• Title/Summary/Keyword: Fan expression

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Isolation, Characterization, and Molecular Cloning of the cDNA Encoding a Novel Phytase from Aspergillus niger 113 and High Expression in Pichia pastoris

  • Xiong, Ai Sheng;Yao, Quan-Hong;Peng, Ri-He;Li, Xian;Fan, Hui-Qin;Guo, Mei-Jin;Zhang, Si-Liang
    • BMB Reports
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    • v.37 no.3
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    • pp.282-291
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    • 2004
  • Phytases catalyze the release of phosphate from phytic acid. Phytase-producing microorganisms were selected by culturing the soil extracts on agar plates containing phytic acid. Two hundred colonies that exhibited potential phytase activity were selected for further study. The colony showing the highest phytase activity was identified as Aspergillus niger and designated strain 113. The phytase gene from A. niger 113 (phyI1) was isolated, cloned, and characterized. The nucleotide and deduced amino acid sequence identity between phyI1 and phyA from NRRL3135 were 90% and 98%, respectively. The identity between phyI1 and phyA from SK-57 was 89% and 96%. A synthetic phytase gene, phyI1s, was synthesized by successive PCR and transformed into the yeast expression vector carrying a signal peptide that was designed and synthesized using P. pastoris biased codon. For the phytase expression and secretion, the construct was integrated into the genome of P. pastoris by homologous recombination. Over-expressing strains were selected and fermented. It was discovered that ~4.2 g phytase could be purified from one liter of culture fluid. The activity of the resulting phytase was 9.5 U/mg. Due to the heavy glycosylation, the expressed phytase varied in size (120, 95, 85, and 64 kDa), but could be deglycosylated to a homogeneous 64 kDa species. An enzymatic kinetics analysis showed that the phytase had two pH optima (pH 2.0 and pH 5.0) and an optimum temperature of $60^{\circ}C$.

Knockdown of HMGN5 Expression by RNA Interference Induces Cell Cycle Arrest in Human Lung Cancer Cells

  • Chen, Peng;Wang, Xiu-Li;Ma, Zhong-Sen;Xu, Zhong;Jia, Bo;Ren, Jin;Hu, Yu-Xin;Zhang, Qing-Hua;Ma, Tian-Gang;Yan, Bing-Di;Yan, Qing-Zhu;Li, Yan-Lei;Li, Zhen;Yu, Jin-Yan;Gao, Rong;Fan, Na;Li, Bo;Yang, Jun-Ling
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3223-3228
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    • 2012
  • HMGN5 is a typical member of the HMGN (high mobility group nucleosome-binding protein) family which may function as a nucleosomal binding and transcriptional activating protein. Overexpression of HMGN5 has been observed in several human tumors but its role in tumorigenesis has not been fully clarified. To investigate its significance for human lung cancer progression, we successfully constructed a shRNA expression lentiviral vector in which sense and antisense sequences targeting the human HMGN5 were linked with a 9-nucleotide loop. Inhibitory effects of siRNA on endogenous HMGN5 gene expression and protein synthesis were demonstrated via real-time RT-PCR and western blotting. We found HMGN5 silencing to significantly inhibit A549 and H1299 cell proliferation assessed by MTT, BrdU incorporation and colony formation assays. Furthermore, flow cytometry analysis showed that specific knockdown of HMGN5 slowed down the cell cycle at the G0/G1 phase and decreased the populations of A549 and H1299 cells at the S and G2/M phases. Taken together, these results suggest that HMGN5 is directly involved in regulation cell proliferation in A549 and H1299 cells by influencing signaling pathways involved in cell cycle progression. Thus, our finding suggests that targeting HMGN5 may be an effective strategy for human lung cancer treatment.

Studies on meat color, myoglobin content, enzyme activities, and genes associated with oxidative potential of pigs slaughtered at different growth stages

  • Yu, Qin Ping;Feng, Ding Yuan;Xiao, Juan;Wu, Fan;He, Xiao Jun;Xia, Min Hao;Dong, Tao;Liu, Yi Hua;Tan, Hui Ze;Zou, Shi Geng;Zheng, Tao;Ou, Xian Hua;Zuo, Jian Jun
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.12
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    • pp.1739-1750
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    • 2017
  • Objective: This experiment investigated meat color, myoglobin content, enzyme activities, and expression of genes associated with oxidative potential of pigs slaughtered at different growth stages. Methods: Sixty 4-week-old $Duroc{\times}Landrace{\times}Yorkshire$ pigs were assigned to 6 replicate groups, each containing 10 pigs. One pig from each group was sacrificed at day 35, 63, 98, and 161 to isolate longissimus dorsi and triceps muscles. Results: Meat color scores were higher in pigs at 35 d than those at 63 d and 98 d (p<0.05), and those at 98 d were lower than those at 161 d (p<0.05). The total myoglobin was higher on 161 d compared with those at 63 d and 98 d (p<0.05). Increase in the proportions of metmyoglobin and deoxymyoglobin and a decrease in oxymyoglobin were observed between days 35 and 161 (p<0.05). Meat color scores were correlated to the proportion of oxymyoglobin (r = 0.59, p<0.01), and negatively correlated with deoxymyoglobin and metmyoglobin content (r = -0.48 and -0.62, p<0.05). Malate dehydrogenase (MDH) activity at 35 d and 98 d was higher than that at 161 d (p<0.05). The highest lactate dehydrogenase/MDH ratio was achieved at 161 d (p<0.05). Calcineurin mRNA expression decreased at 35 d compared to that at 63 d and 98 d (p<0.05). Myocyte enhancer factor 2 mRNA results indicated a higher expression at 161 d than that at 63 d and 98 d (p<0.05). Conclusion: Porcine meat color, myoglobin content, enzyme activities, and genes associated with oxidative potential varied at different stages.

Adenosine A3 Receptor Mediates ERK1/2- and JNK-Dependent TNF-α Production in Toxoplasma gondii-Infected HTR8/SVneo Human Extravillous Trophoblast Cells

  • Ye, Wei;Sun, Jinhui;Li, Chunchao;Fan, Xuanyan;Gong, Fan;Huang, Xinqia;Deng, Mingzhu;Chu, Jia-Qi
    • Parasites, Hosts and Diseases
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    • v.58 no.4
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    • pp.393-402
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    • 2020
  • Toxoplasma gondii is an intracellular parasite that causes severe disease when the infection occurs during pregnancy. Adenosine is a purine nucleoside involved in numerous physiological processes; however, the role of adenosine receptors in T. gondii-induced trophoblast cell function has not been investigated until now. The goal of the present study was to evaluate the intracellular signaling pathways regulated by adenosine receptors using a HTR-8/SVneo trophoblast cell model of T. gondii infection. HTR8/SVneo human extravillous trophoblast cells were infected with or without T. gondii and then evaluated for cell morphology, intracellular proliferation of the parasite, adenosine receptor expression, TNF-α production and mitogen-activated protein (MAP) kinase signaling pathways triggered by adenosine A3 receptor (A3AR). HTR8/SVneo cells infected with T. gondii exhibited an altered cytoskeletal changes, an increased infection rate and reduced viability in an infection time-dependent manner. T. gondii significantly promoted increased TNF-α production, A3AR protein levels and p38, ERK1/2 and JNK phosphorylation compared to those observed in uninfected control cells. Moreover, the inhibition of A3AR by A3AR siRNA transfection apparently suppressed the T. gondii infection-mediated upregulation of TNF-α, A3AR production and MAPK activation. In addition, T. gondii-promoted TNF-α secretion was dramatically attenuated by pretreatment with PD098059 or SP600125. These results indicate that A3AR-mediated activation of ERK1/2 and JNK positively regulates TNF-α secretion in T. gondii-infected HTR8/SVneo cells.

Ginsengenin derivatives synthesized from 20(R)-panaxotriol: Synthesis, characterization, and antitumor activity targeting HIF-1 pathway

  • Guo, Hong-Yan;Xing, Yue;Sun, Yu-Qiao;Liu, Can;Xu, Qian;Shang, Fan-Fan;Zhang, Run-Hui;Jin, Xue-Jun;Chen, Fener;Lee, Jung Joon;Kang, Dongzhou;Shen, Qing-Kun;Quan, Zhe-Shan
    • Journal of Ginseng Research
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    • v.46 no.6
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    • pp.738-749
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    • 2022
  • Background: Ginseng possesses antitumor effects, and ginsenosides are considered to be one of its main active chemical components. Ginsenosides can further be hydrolyzed to generate secondary saponins, and 20(R)-panaxotriol is an important sapogenin of ginsenosides. We aimed to synthesize a new ginsengenin derivative from 20(R)-panaxotriol and investigate its antitumor activity in vivo and in vitro. Methods: Here, 20(R)-panaxotriol was selected as a precursor and was modified into its derivatives. The new products were characterized by 1H-NMR, 13C-NMR and HR-MS and evaluated by molecular docking, MTT, luciferase reporter assay, western blotting, immunofluorescent staining, colony formation assay, EdU labeling and immunofluorescence, apoptosis assay, cells migration assay, transwell assay and in vivo antitumor activity assay. Results: The derivative with the best antitumor activity was identified as 6,12-dihydroxy-4,4,8,10,14-pentamethyl-17-(2,6,6-trimethyltetrahydro-2H-pyran-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-yl(tert-butoxycarbonyl)glycinate (A11). The focus of this research was on the antitumor activity of the derivatives. The efficacy of the derivative A11 (IC50 < 0.3 µM) was more than 100 times higher than that of 20(R)- panaxotriol (IC50 > 30 µM). In addition, A11 inhibited the protein expression and nuclear accumulation of the hypoxia-inducible factor HIF-1α in HeLa cells under hypoxic conditions in a dose-dependent manner. Moreover, A11 dose-dependently inhibited the proliferation, migration, and invasion of HeLa cells, while promoting their apoptosis. Notably, the inhibition by A11 was more significant than that by 20(R)-panaxotriol (p < 0.01) in vivo. Conclusion: To our knowledge, this is the first study to report the production of derivative A11 from 20(R)-panaxotriol and its superior antitumor activity compared to its precursor. Moreover, derivative A11 can be used to further study and develop novel antitumor drugs.

Cloning, Expression, and Characterization of Protease-resistant Xylanase from Streptomyces fradiae var. k11

  • Li, Ning;Yang, Peilong;Wang, Yaru;Luo, Huiying;Meng, Kun;Wu, Nigfeng;Fan, Yunliu;Yao, Bin
    • Journal of Microbiology and Biotechnology
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    • v.18 no.3
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    • pp.410-416
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    • 2008
  • The gene SfXyn10, which encodes a protease-resistant xylanase, was isolated using colony PCR screening from a genomic library of a feather-degrading bacterial strain Streptomyces fradiae var. k11. The full-length gene consists of 1,437bp and encodes 479 amino acids, which includes 41 residues of a putative signal peptide at its N terminus. The amino acid sequence shares the highest similarity (80%) to the endo-1,4-${\beta}$-xylanase from Streptomyces coelicolor A3, which belongs to the glycoside hydrolase family 10. The gene fragment encoding the mature xylanase was expressed in Escherichia coli BL21 (DE3). The recombinant protein was purified to homogeneity by acetone precipitation and anion-exchange chromatography, and subsequently characterized. The optimal pH and temperature for the purified recombinant enzyme were 7.8 and $60^{\circ}C$, respectively. The enzyme showed stability over a pH range of 4.0-10.0. The kinetic values on oat spelt xylan and birchwood xylan substrates were also determined. The enzyme activity was enhanced by $Fe^{2+}$ and strongly inhibited by $Hg^{2+}$ and SDS. The enzyme also showed resistance to neutral and alkaline proteases. Therefore, these characteristics suggest that SfXyn10 could be an important candidate for protease-resistant mechanistic research and has potential applications in the food industry, cotton scouring, and improving animal nutrition.

Short hairpin RNA targeting of fibroblast activation protein inhibits tumor growth and improves the tumor microenvironment in a mouse model

  • Cai, Fan;Li, Zhiyong;Wang, Chunting;Xian, Shuang;Xu, Guangchao;Peng, Feng;Wei, Yuquan;Lu, You
    • BMB Reports
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    • v.46 no.5
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    • pp.252-257
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    • 2013
  • Fibroblast activation protein (FAP) is a specific serine protease expressed in tumor stroma proven to be a stimulatory factor in the progression of some cancers. The purpose of this study was to investigate the effects of FAP knockdown on tumor growth and the tumor microenvironment. Mice bearing 4T1 subcutaneous tumors were treated with liposome-shRNA complexes targeting FAP. Tumor volumes and weights were monitored, and FAP, collagen, microvessel density (MVD), and apoptosis were measured. Our studies showed that shRNA targeting of FAP in murine breast cancer reduces FAP expression, inhibits tumor growth, promotes collagen accumulation (38%), and suppresses angiogenesis (71.7%), as well as promoting apoptosis (by threefold). We suggest that FAP plays a role in tumor growth and in altering the tumor microenvironment. Targeting FAP may therefore represent a supplementary therapy for breast cancer.

Molecular Characterization, Chromosomal Localizations, Expression Profile, and Association Analysis of the Porcine PECI Gene with Carcass Traits

  • Gao, H.;Fan, B.;Zhu, M.J.;Liu, Bang
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.1
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    • pp.7-12
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    • 2010
  • The full-length cDNA of the porcine peroxisomal ${\Delta}^3$,${\Delta}^2$-enoyl-CoA isomerase (PECI) gene encodes a monofunctional peroxisomal ${\Delta}^3$,${\Delta}^2$-enoyl-CoA isomerase. Cloning and sequencing of the porcine PECI cDNA revealed the presence of an 1185-base pair open reading frame predicted to encode a 394-amino acid protein by the 5'rapid amplification of cDNA ends (5'RACE) and EST sequences. The porcine PECI gene was expressed in seven tissues (heart, liver, spleen, lung, kidney, skeletal muscle, fat) which was revealed by reverse transcriptase-polymerase chain reaction (RT-PCR). The porcine PECI was mapped to SSC71/2 p11-13 using the somatic cell hybrid panel (SCHP) and the radiation hybrid panel (RH) (LOD score 12.84). The data showed that PECI was closely linked to marker S0383. A C/T single nucleotide polymorphism in PECI exon 10 (3'UTR) was detected as a PvuII PCR-RFLP. Association analysis in our experimental pig population showed that different genotypes of PECI gene were significantly associated with the Average Backfat thickness (ABF) (p<0.05) and Buttock backfat thickness (p<0.01).

Transcriptomic Features of Echinococcus granulosus Protoscolex during the Encystation Process

  • Fan, Junjie;Wu, Hongye;Li, Kai;Liu, Xunuo;Tan, Qingqing;Cao, Wenqiao;Liang, Bo;Ye, Bin
    • Parasites, Hosts and Diseases
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    • v.58 no.3
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    • pp.287-299
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    • 2020
  • Cystic echinococcosis (CE) is a zoonotic infection caused by Echinococcus granulosus larvae. It seriously affects the development of animal husbandry and endangers human health. Due to a poor understanding of the cystic fluid formation pathway, there is currently a lack of innovative methods for the prevention and treatment of CE. In this study, the protoscoleces (PSCs) in the encystation process were analyzed by high-throughput RNA sequencing. A total of 32,401 transcripts and 14,903 cDNAs revealed numbers of new genes and transcripts, stage-specific genes, and differently expressed genes. Genes encoding proteins involved in signaling pathways, such as putative G-protein coupled receptor, tyrosine kinases, and serine/threonine protein kinase, were predominantly up-regulated during the encystation process. Antioxidant enzymes included cytochrome c oxidase, thioredoxin glutathione, and glutathione peroxidase were a high expression level. Intriguingly, KEGG enrichment suggested that differentially up-regulated genes involved in the vasopressin-regulated water reabsorption metabolic pathway may play important roles in the transport of proteins, carbohydrates, and other substances. These results provide valuable information on the mechanism of cystic fluid production during the encystation process, and provide a basis for further studies on the molecular mechanisms of growth and development of PSCs.

Exosomes from CIITA-Transfected CT26 Cells Enhance Anti-tumor Effects

  • Fan, Wen;Tian, Xing-De;Huang, E.;Zhang, Jia-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.2
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    • pp.987-991
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    • 2013
  • Aim: To study anti-tumor effects of exosomes from class II transactivator (CIITA) gene transfected CT26 cells. Methods: In this study, we established an MHC class II molecule-expressing murine colon cancer cell line (CT26-CIITA) by transduction of the CIITA gene. Immune effects in vitro and tumor protective results in vivo were tested and monitored. Results: Exosomes from CT26-CIITA cells were found to contain a high level of MHC class II protein. When loaded on dendritic cells (DCs), exosomes from CT26-CIITA cells significantly increased expression of MHC class II molecules, CD86 and CD80, as compared to exosomes from CT26 cells. In vitro assays using co-culture of immunized splenocytes and exosome-loaded DCs demonstrated that CIITA-Exo enhanced splenocyte proliferation and IFN-${\gamma}$ production of CD4+T cells, while inhibiting IL-10 secretion. In addition, compared to exosomes from CT26 cells, CT26-CIITA-derived exosomes induced higher TNF-${\alpha}$ and IL-12 mRNA levels. A mouse tumour preventive model showed that CT26-CIITA derived exosomes significantly inhibited tumour growth in a dose-dependent manner and significantly prolonged the survival time of tumour-bearing mice. Conclusion: Our findings indicate that CT26-CIITA-released exosomes are more efficient to induce anti-tumour immune responses, suggesting a potential role of MHC class II-containing tumour exosomes as cancer vaccine candidates.