Qingyou Liu

Guangxi University, Yung-ning, Guangxi Zhuangzu Zizhiqu, China

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Publications (12)21.37 Total impact

  • Asian Australasian Journal of Animal Sciences 11/2015; DOI:10.5713/ajas.15.0592 · 0.54 Impact Factor
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    ABSTRACT: Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven‑hoofed animals, which leads to serious economical losses. FMDV is not adequately controlled by vaccination or biosecurity measures. To generate genetically modified FMDV‑resistant animals, a combinatorial expression cassette producing three short hairpin (sh)RNAs was constructed using the lentivirus (LV) vector, LV‑3shRNA. The three shRNAs were expressed under the regulation of DNA polymerase III promoters from a buffalo and a bovine source, with one targeted to the non‑structural protein 3B, and the other two targeted to the viral polymerase protein 3D of FMDV, respectively. The role of LV‑3shRNA in the inhibition of the replication of FMDV was determined in BHK‑21 cells and in suckling mice. The results revealed that LV‑3shRNA reduced viral growth 3‑fold (24 h post‑infection) when the cells were challenged with 107‑times the tissue culture infective dose (TCID50)/ml of O serotype FMDV. The suckling mice pretreated with LV‑3shRNA were completely protected on administration of 5‑times the dose of FMDV otherwise sufficient to kill 50% of the experimental animals (LD50). These results demonstrated that the LV‑mediated dual expression of three FMDV‑specific shRNAs provided a novel strategy towards combating FMDV, which facilitates the permanent introduction of novel disease-resistance traits into the buffalo and bovine genomes in the future.
    Molecular Medicine Reports 08/2015; 12(5). DOI:10.3892/mmr.2015.4246 · 1.55 Impact Factor
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    ABSTRACT: The present study was undertaken to examine the effect of Scriptaid treatment on histone acetylation, DNA methylation, expression of genes related to histone acetylation, and development of buffalo somatic cell nuclear transfer (SCNT) embryos. Treatment of buffalo SCNT embryos with 500 nM Scriptaid for 24 h resulted in a significant increase in the blastocyst formation rate (28.2% vs. 13.6%, p<0.05). Meanwhile, treatment of buffalo SCNT embryos with Scriptaid also resulted in higher acetylation levels of H3K18 and lower methylation levels of global DNA at the blastocyst stage, which was similar to fertilized counterparts. The expression levels of CBP, p300, HAT1, Dnmt1, and Dnmt3a in SCNT embryos treated with Scriptaid were significantly lower than the control group at the eight-cell stage (p<0.05), but the expression of HAT1 and Dnmt1a was higher than the control group at the blastocyst stage (p<0.05). When 96 blastocysts developed from Scriptaid-treated SCNT embryos were transferred into 48 recipients, 11 recipients (22.9%) became pregnant, whereas only one recipient (11.1%) became pregnant following transfer of 18 blastocysts developed from untreated SCNT embryos into nine recipients. These results indicate that treatment of buffalo SCNT embryos with Scriptaid can improve their developmental competence, and this action is mediated by resulting in a similar histone acetylation level and global DNA methylation level compared to in vitro-fertilized embryos through regulating the expression pattern of genes related to histone acetylation and DNA methylation.
    06/2015; 17(5). DOI:10.1089/cell.2014.0084
  • Yanping Ren · Xiangping Li · Qingyou Liu · Yanfei Deng · Deshun Shi ·
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    ABSTRACT: Reporter genes are often used as markers to track the integration and expression of target genes in animal genetic engineering. To avoid potential side effects from reporter genes, in this study an improved Tet-on system was developed to control reporter gene expression, and its effectiveness was explored in transgenic cells. First, the rtTA protein was fused with Tat and NLS proteins to obtain the prokaryotic expression vector pET32a-Tat-rtTA-NSL. A eukaryotic transgenic vector was constructed, p-HS4-BPA-TmA-HS4, in which the reporter (mCherry) and target (PRL) genes were promoted by TRE and BCN, respectively. After confirming the functionality of the transgenic vector, purified rtTA protein and Dox were added to induce expression of the mCherry gene. The optimal amount of purified rtTA protein, its influence on target gene expression, and the time of rtTA protein action were each investigated separately. The results showed that rtTA protein was expressed in transformed E. coli with IPTG induction. TRE could promote mCherry gene expression by co-transfecting the constructed transgenic vector and prtTA plasmid. When purified rtTA protein and Dox were added, red fluorescence was observed in Bcap-37 cells transfected with the p-HS4-BPA-TmA-HS4 vector, and the exogenous PRL gene was expressed regardless of mCherry gene expression. The optimal amount of rtTA protein was 16 μg/mL, and it needed about 6 h to promote mCherry gene expression in transfected cells. These results demonstrate that the expression of the mCherry reporter gene can be tightly and conditionally regulated by our Tet-on system.
    Biotechnology and Bioprocess Engineering 02/2015; 20(1):44-50. DOI:10.1007/s12257-014-0422-9 · 1.11 Impact Factor
  • Mengmei Li · Lanyu Li · Jun Zhang · Vinod Verma · Qingyou Liu · Deshun Shi · Ben Huang ·

    Stem Cell Discovery 01/2015; 05(01):1-9. DOI:10.4236/scd.2015.51001
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    ABSTRACT: N-3 polyunsaturated fatty acids (n-3 PUFAs) have their first double bond at the third carbon from the methyl end of the fatty-acid chain and had been proven to be beneficial to human health. However, mammals cannot produce n-3 PUFAs by themselves because they lack the n-3 fatty-acid desaturase (Fat-1) gene. Thus, the possibility of producing sFat-1 transgenic rabbits was explored in this study. The transgenic cassette of pPGK1-sFat-1-CMV-EGFP was constructed and transgenic rabbit embryos were produced by intracytoplasmic sperm injection (ICSI). When 123 EGFP-positive embryos at the 2-8-cell stage were transplanted into the oviduct of four oestrous-synchronised recipients, two of them became pregnant and gave birth to seven pups. However, transfer of embryos into the uterus of oestrous-synchronised recipients and oviduct or uterus of oocyte donor rabbits did not result in pregnancy. The integration of the sFat-1 gene was confirmed in six of the seven live pups by PCR and Southern blot. The expression of the sFat-1 gene in the six transgenic pups was also detected by reverse transcription polymerase chain reaction (RT-PCR). Gas chromatography-mass spectrometry analysis revealed that transgenic rabbits exhibited an ~15-fold decrease in the ratio of n-6:n-3 PUFAs in muscle compared with wild-type rabbits and non-transgenic rabbits. These results demonstrate that sFat-1 transgenic rabbits can be produced by ICSI and display a low ratio of n-6:n-3 PUFAs.
    Reproduction Fertility and Development 07/2014; DOI:10.1071/RD13413 · 2.40 Impact Factor
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    Xiaoxi Zhang · Qingyou Liu · Chan Luo · Yanfei Deng · Kuiqing Cui · Deshun Shi ·
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    ABSTRACT: RNA polymerase III (pol III) type 3 promoters, such as 7SK and U6, are routinely used to induce short hairpin RNAs (shRNAs) to knockdown gene expression by RNA interference (RNAi). To extend the application of RNAi to studies of buffalo, an shRNAs expressing system using the buffalo pol III promoters was developed. Buffalo 7SK promoter (bu7SK) and U6 promoter (buU6) sequences upstream of the full-length 7SK and U6 small nuclear RNA sequence in the buffalo genome were identified and characterized, respectively. To determine the functionality of these promoters in constructs driving shRNA expression, anti-EGFP shRNAs (shEGFP) cassettes under the direction of bu7SK and buU6 were constructed. We further compared the EGFP knockdown efficiency of constructs using bu7SK and buU6 with that of promoters of human and bovine origins in BFF cells and mouse PT67 cells by flow cytometry and quantitative real-time PCR assays. We found that the bu7SK and buU6 promoters induced the greatest level of suppression in homologous and heterologous cells relative to promoters derived from other species. Taken together, functional bu7SK and buU6 promoters were identified and characterized, thus laying the groundwork for future development of RNAi therapeutics and gene modification in buffalo species.
    International Journal of Molecular Sciences 02/2014; 15(2):2596-607. DOI:10.3390/ijms15022596 · 2.86 Impact Factor
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    ABSTRACT: It has been reported that buffalo (Bubalus bubalis) embryos reconstructed by somatic cell nucleus transfer (SCNT) can develop to the full term of gestation and result in newborn calves. However, the developmental competence of reconstructed embryos is still low. Recently, it has been reported that treating donor cells or embryos with trichostatin A (TSA) can increase the cloning efficiency in some species. Thus, the present study was undertaken to improve the development of buffalo SCNT embryos by treatment of donor cells (buffalo fetal fibroblasts) with TSA and explore the relation between histone acetylation status of donor cells and developmental competence of SCNT embryos. Treatment of donor cells with either 0.15 or 0.3 μM TSA for 48 hours resulted in a significant increase in the cleavage rate and blastocyst yield of SCNT embryos (P < 0.05). Meanwhile, the expression level of HDAC1 in donor cells was also decreased (0.4-0.6 fold, P < 0.05) by TSA treatment, although the expression level of HAT1 was not affected. Further measurement of the epigenetic maker AcH4K8 in buffalo IVF and SCNT embryos at the eight-cell stage revealed that the spatial distribution of acH4K8 staining in SCNT embryos was different from the IVF embryos. Treatment of donor cells with TSA resulted in an increase in the AcH4K8 level of SCNT embryos and similar to fertilized counterparts. These results suggest that treatment of donor cells with TSA can facilitate their nucleus reprogramming by affecting the acetylated status of H4K8 and improving the in vitro development of buffalo SCNT embryos. The AcH4K8 status at the eight-cell stage can be used as an epigenetic marker for predicting the SCNT efficiency in buffalos.
    Theriogenology 09/2013; 80(8). DOI:10.1016/j.theriogenology.2013.07.013 · 1.80 Impact Factor
  • Hui Li · Xiangping Li · Qingyou Liu · Zhendan Shi · Deshun Shi ·
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    ABSTRACT: Human interferon alpha 2b (IFNα-2b) is a pleiotropic cytokine used to treat various viral diseases and cancers. Conventionally, recombinant human IFNα-2b used in clinics was produced by prokaryotic expression system, which always lack of enough biological activity due to limitations on proper folding and post-translational modifications, so the eukaryotic expression system are becoming prevailing method for the production of recombinant proteins. In this study, human breast cancer cell Bcap-37 was firstly used as host for the expression of human IFNα-2b, with the expression vector pIRES2-IFN-EGFP, in which IFNα-2b gene is under the control of CMV promoter. The expression of recombinant IFNα-2b was detected by Western blot and ELISA. Results showed that the concentration of the secreted recombinant IFNα-2b in culture medium was 435.7 pg/mL/24 h. Biological activity of the recombinant IFNα-2b was assayed by detecting the expression of IFN-inducible genes, including MxA, OAS, PKR, and Caspase1 through QRT-PCR. Results demonstrated that recombinant IFNα-2b possess the biological activities. Compared to non-transgenic cells, the expression levels of the aforementioned four IFN-inducible genes were increased by 18.098-, 1.843-, 2.21-, and 3.066-folds, respectively. We got to a conclusion that the human breast cancer cell Bcap-37 could express bioactive recombinant IFNα-2b.
    Applied biochemistry and biotechnology 08/2013; 171(6). DOI:10.1007/s12010-013-0420-y · 1.74 Impact Factor
  • Hui Li · Qingyou Liu · Kuiqing Cui · Jinfeng Liu · Yanping Ren · Deshun Shi ·
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    ABSTRACT: Interferon alpha 2b (IFNα-2b) is an important immune regulator widely used in clinic, for the treatment of chronic hepatitis, hairy cell leukemia, chronic myelogenous leukemia and multiple myeloma, etc. The clinically used IFNα-2b is generally produced by E.Coli, which lacks the post-translational O-glycosylation presents on naturally synthesized protein, and has a short serum half-life. In this study, a transgenic cassette pBCN-IFN-pA-CMV-EGFP was constructed, with a 5.2 kb beta-casein regulation fragment from Jersey cow and a 6×His tagged human Interferon alpha 2b (hIFNα-2b) gene fragment. By using pronuclear microinjection technique, transgenic mice were generated and the expression of IFNα-2b in the milk was assayed. The hIFNα-2b was correctly translated in milk of transgenic mice according to Western blot analysis. The expression level of hIFNα-2b was varied among the transgenic mice, and the highest one was about 29.71 μg/L. The recombinant protein exhibited biological activity in vitro by increasing the luminescence value and the MxA gene expression in established WISH cells, and the specific activity is approximately 2.8 × 10(7 )IU/mg. The expression of recombinant hIFNα-2b in mammary glands of transgenic mice constitutes an important step towards low-cost and full biological activity production of this protein drug in mammary gland bioreactor.
    Transgenic Research 06/2012; 22(1). DOI:10.1007/s11248-012-9623-1 · 2.32 Impact Factor
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    ABSTRACT: Ectopically, expression of defined factors could reprogram mammalian somatic cells into induced pluripotent stem cells (iPSCs), which initiates a new strategy to obtain pluripotent stem cell lines. Attempts have been made to generate buffalo pluripotent stem cells by culturing primary germ cells or inner cell mass, but the efficiency is extremely low. Here, we report a successful method to reprogram buffalo fetal fibroblasts (BFFs) into pluripotent stem cells [buffalo induced pluripotent stem cell (biPSCs)] by transduction of buffalo defined factors (Oct4, Sox2, Klf4, and c-Myc) using retroviral vectors. The established biPSCs displayed typical morphological characteristics of pluripotent stem cells, normal karyotype, positive staining of alkaline phosphatase, and expressed pluripotent markers including Oct4, Sox2, Nanog, Lin28, E-Cadherin, SSEA-1, SSEA-4, TRA-1-81, STAT3, and FOXD3. They could form embryoid bodies (EBs) in vitro and teratomas after injecting into the nude BALB/C mice, and 3 germ layers were identified in the EBs and teratomas. Methylation assay revealed that the promoters of Oct4 and Nanog were hypomethylated in biPSCs compared with BFFs and pre-biPSCs, while the promoters of Sox2 and E-Cadherin were hypomethylated in both BFFs and biPSCs. Further, inhibiting p53 expression by coexpression of SV40 large T antigen and buffalo defined factors in BFFs or treating BFFs with p53 inhibitor pifithrin-a (PFT) could increase the efficiency of biPSCs generation up to 3-fold, and nuclear transfer embryos reconstructed with biPSCs could develop to blastocysts. These results indicate that BFFs can be reprogrammed into biPSCs by buffalo defined factors, and the generation efficiency of biPSCs can be increased by inhibition of p53 expression. These efforts will provide a feasible approach for investigating buffalo stem cell signal pathways, establishing buffalo stem cell lines, and producing genetic modification buffaloes in the future.
    Stem cells and development 03/2012; 21(13):2485-94. DOI:10.1089/scd.2012.0018 · 3.73 Impact Factor
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    ABSTRACT: Cloning of buffalos (Bubalus bubalis) through nuclear transfer is a potential alternative approach in genetic improvement of buffalos. However, to our knowledge, cloned offspring of buffalos derived from embryonic, fetal, or somatic cells have not yet been reported. Thus, factors affecting the nuclear transfer of buffalo somatic cells were examined, and the possibility of cloning buffalos was explored in the present study. Treatment of buffalo fibroblasts and granulosa cells with aphidicolin plus serum starvation resulted in more cells being arrested at the G0/G1 phase, the proportion of cells with DNA fragmentation being less, and the number of embryos derived from these cells that developed to blastocysts being greater. In addition, a difference was found in the development of embryos reconstructed with fetal fibroblasts from different individuals (P < 0.001). Forty-two blastocysts derived from granulosa cells and fetal fibroblasts were transferred into 21 recipient swamp buffalos, and 4 recipients were confirmed to be pregnant by rectal palpation on Day 60 of gestation. One recipient received two embryos from fetal fibroblasts aborted on Day 300 of gestation and delivered two female premature calves. Three recipients maintained pregnancy to term and delivered three female cloned calves after Days 338-349 of gestation. These results indicate that buffalo embryos derived from either fetal fibroblasts or granulosa cells can develop to the term of gestation and result in newborn calves.
    Biology of Reproduction 09/2007; 77(2):285-91. DOI:10.1095/biolreprod.107.060210 · 3.32 Impact Factor