• Title/Summary/Keyword: Knockout

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Alloimmune and Skin Allograft Responses In 4-1BB (CD137)-deficient Mice

  • Wolisi, Godwin;Srirangam, Anjaiah;Vinay, Dass S.;Suh, Jae H.;Suh, Ho-Seok;Choi, Beom K.;Kwon, Byoung S.
    • IMMUNE NETWORK
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    • v.2 no.3
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    • pp.133-136
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    • 2002
  • Background: The costimulatory molecule 4-1BB, a member of nerve growth factor receptor/tumor necrosis factor (NGFR/TNFR) super family, is involved in cell survival and death. Methods: In this study, female C57BL/6 ($H-2^b$) mice were used as a recipient, and DBA/2 ($H-2^d$) as a donor to assess a mixed lymphocyte reaction (MLR) and CTL response in vitro, and skin graft survival. IL-2, IFN level was measured by ELISA. Results: Mixed lymphocyte reaction (MLR) analysis showed that 4-1BB-deficient responder cells showed enhanced cellular proliferation over littermate controls. In contrast, IL-2 production was diminished only in 4-1BB knockout cultures. The IFN expression, on the other hand, was comparable between the groups. When female C57BL/6 ($H-2^b$) mice were grafted with the trunk skin of DBA/2 ($H-2^d$) mice, the in vivo tissue destruction of 4-1BB-deficient mice was not distinct from the normal littermates. Conclusion: These data suggest that 4-1BB is critical for the induction of alloreactive responses in vitro but 4-1BB alone could not change the course of skin rejection in vivo.

Enhancement of Allergen-induced Airway Inflammation by NOX2 Deficiency

  • Won, Hee-Yeon;Jang, Eun-Jung;Min, Hyun-Jung;Hwang, Eun-Sook
    • IMMUNE NETWORK
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    • v.11 no.3
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    • pp.169-174
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    • 2011
  • Background: NADPH oxidase (NOX) modulates cell proliferation, differentiation and immune response through generation of reactive oxygen species. Particularly, NOX2 is recently reported to be important for regulating Treg cell differentiation of CD4+ T cells. Methods: We employed ovalbumin-induced airway inflammation in wild-type and NOX2-deficient mice and analyzed tissue histopathology and cytokine profiles. Results: We investigated whether NOX2-deficiency affects T cell-mediated airway inflammation. Ovalbumin injection which activates T cell-mediated allergic response increased airway inflammation in wild-type mice, as evidenced by increased immune cell infiltration, allergic cytokine expression, and goblet cell hyperplasia in the lung. Interestingly, NOX2 knockout (KO) mice were more susceptible to allergen-induced lung inflammation compared to wild-type mice. Immune cells including neutrophils, lymphocytes, macrophages, and eosinophils were drastically infiltrated into the lung of NOX2 KO mice and mucus secretion was substantially increased in deficiency of NOX2. Furthermore, inflammatory allergic cytokines and eotaxin were significantly elevated in NOX2 KO mice, in accordance with enhanced generation of inflammatory cytokines interleukin-17 and interferon-${\gamma}$ by CD4+ T cells. Conclusion: These results indicate that NOX2 deficiency favorably produces inflammatory cytokines by T cells and thus increases the susceptibility to severe airway inflammation.

Predominant $D_1$ Receptors Involvement in the Over-expression of CART Peptides after Repeated Cocaine Administration

  • Hu, Zhenzhen;Oh, Eun-Hye;Chung, Yeon Bok;Hong, Jin Tae;Oh, Ki-Wan
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.2
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    • pp.89-97
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    • 2015
  • The aim of this study was to investigate the involvement of dopaminergic receptors (DR) in behavioral sensitization, as measured by locomotor activity, and the over-expression of cocaine- and amphetamine-regulated transcript (CART) peptides after repeated administration of cocaine in mice. Repeated administrations of cocaine induced behavioral sensitization and CART over-expression in mice. The levels of striatal CART mRNA were significantly increased on the $3^{rd}$ day. CART peptides were over-expressed on the $5^{th}$ day in the striata of behaviorally sensitized mice. A higher proportion of $CART^+$ cells in the cocaine-treated mice were present in the nucleus accumbens (NAc) shell than in the dorsolateral (DL) part of caudate putamen (CP). The concomitant administration of both $D_1R$ and $D_2R$ antagonists, SCH 23390 ($D_1R$ selective) and raclopride ($D_2R$ selective), blocked cocaine induced-behavioral sensitization, CART over-expression, and cyclic adenosine 5'-monophosphate (cAMP)/ protein kinase A (PKA)/phospho-cAMP response element-binding protein (pCREB) signal pathways. SCH 23390 more predominantly inhibited the locomotor activity, CART over-expression, pCREB and PKA activity than raclopride. Cocaine induced-behavioral sensitization was also attenuated in the both $D_1R$ and $D_2R$ knockout (KO) mice, respectively. CART over-expression and activated cAMP/PKA/pCREB signal pathways were inhibited in the $D_1R$-KO mice, but not in the $D_2R$-KO mice. It is suggested that behavioral sensitization, CART over-expression and activated cAMP/PKA/pCREB signal pathways induced by repeated administration of cocaine could be more predominantly mediated by $D_1R$.

Targeted Editing of Myostatin Gene in Sheep by Transcription Activator-like Effector Nucleases

  • Zhao, Xinxia;Ni, Wei;Chen, Chuangfu;Sai, Wujiafu;Qiao, Jun;Sheng, Jingliang;Zhang, Hui;Li, Guozhong;Wang, Dawei;Hu, Shengwei
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.3
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    • pp.413-418
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    • 2016
  • Myostatin (MSTN) is a secreted growth factor expressed in skeletal muscle and adipose tissue that negatively regulates skeletal muscle mass. Gene knockout of MSTN can result in increasing muscle mass in sheep. The objectives were to investigate whether myostatin gene can be edited in sheep by transcription activator-like effector nucleases (TALENs) in tandem with single-stranded DNA oligonucleotides (ssODNs). We designed a pair of TALENs to target a highly conserved sequence in the coding region of the sheep MSTN gene. The activity of the TALENs was verified by using luciferase single-strand annealing reporter assay in HEK 293T cell line. Co-transfection of TALENs and ssODNs oligonucleotides induced precise gene editing of myostatin gene in sheep primary fibroblasts. MSTN gene-edited cells were successfully used as nuclear donors for generating cloned embryos. TALENs combined with ssDNA oligonucleotides provide a useful approach for precise gene modification in livestock animals.

Ectopic Expression of Cenexin1 S796A Mutant in $ODF2^{+/-}$ Knockout Background Causes a Sperm Tail Development Defect

  • Lee, Kyung Ho
    • Development and Reproduction
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    • v.16 no.4
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    • pp.363-370
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    • 2012
  • The outer dense fiber 2 (ODF2) protein is an important component of sperm tail outer dense fiber and localizes at the centrosome. It has been reported that the RO072 ES cell derived homozygote knock out of ODF2 results in an embryonic lethal phenotype, and XL169 ES cell derived heterozygote knock out causes severe defects in sperm tail development. The ODF2s splicing variant, Cenexin1, possesses a C-terminal extension, and the phosphorylation of serine 796 residue in an extended C-terminal is responsible for Plk1 binding. Cenexin1 assembles ninein and causes ciliogenesis in early stages of the cell cycle in a Plk1-independent manner. Alternatively, in the late stages of the cell cycle, G2/M phase, Cenexin1 binds to Plk1 and results in proper mitotic progression. In this study, to identify the in vivo function of Plk1 binding to phosphorylated Cenexin1 S796 residue, and to understand the in vivo functional differences between ODF2 and Cenexin1, we generated ODF2/Cenexin1 S796A/Cenexin1 WT expressing transgenic mice in a RO072 ES cell derived $ODF2^{+/-}$ knock out background. We observed a severe defect of sperm tail development by ectopic expression of Cenexin1 S796A mutant and no phenotypic differences between the ectopic expression of ODF2/Cenexin1 WT in $ODF2^{+/-}$ background and in normal wild type mice.

The Role of Nuclear Receptor Subfamily 1 Group H Member 4 (NR1H4) in Colon Cancer Cell Survival through the Regulation of c-Myc Stability

  • Lee, Yun Jeong;Lee, Eun-Young;Choi, Bo Hee;Jang, Hyonchol;Myung, Jae-Kyung;You, Hye Jin
    • Molecules and Cells
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    • v.43 no.5
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    • pp.459-468
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    • 2020
  • Nuclear receptor subfamily group H member 4 (NR1H4), also known as farnesoid X receptor, has been implicated in several cellular processes in the liver and intestine. Preclinical and clinical studies have suggested a role of NR1H4 in colon cancer development; however, how NR1H4 regulates colon cancer cell growth and survival remains unclear. We generated NR1H4 knockout (KO) colon cancer cells using clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 nuclease (CAS9) technology and explored the effects of NR1H4 KO in colon cancer cell proliferation, survival, and apoptosis. Interestingly, NR1H4 KO cells showed impaired cell proliferation, reduced colony formation, and increased apoptotic cell death compared to control colon cancer cells. We identified MYC as an important mediator of the signaling pathway alterations induced by NR1H4 KO. NR1H4 silencing in colon cancer cells resulted in reduced MYC protein levels, while NR1H4 activation using an NR1H4 ligand, chenodeoxycholic acid, resulted in time- and dose-dependent MYC induction. Moreover, NR1H4 KO enhanced the anti-cancer effects of doxorubicin and cisplatin, supporting the role of MYC in the enhanced apoptosis observed in NR1H4 KO cells. Taken together, our findings suggest that modulating NR1H4 activity in colon cancer cells might be a promising alternative approach to treat cancer using MYC-targeting agents.

Study on Embryo Transfer System for Production of Transgenic Pigs

  • Na, Seungwon;Lee, Euncheol;Kim, Ghangyong;Min, Kyuhong;Yu, Youngkwang;Roy, Pantu Kumar;Fang, Xun;Hassan, Bahia Mohamed Salih;Yoon, Kiyoung;Shin, Sangtae;Cho, Jongki
    • Journal of Embryo Transfer
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    • v.30 no.4
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    • pp.345-350
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    • 2015
  • In the last 10 years, porcine somatic cell nuclear transfer to generate transgenic pig has been performed tremendous development with introduction and knockout of many genes. However, efficiency of porcine somatic cell nuclear transfer is still low and embryo transfer (ET) is one of important step for production efficiency. In porcine ET for production of transgenic cloned pig, we can consider many of points to increase production rates. In respect of seasonality and weather, porcine ET usually is not performed in summer and winter. Cloned transgenic embryos must be transferred into reproductive tracts of recipients where embryos are located after natural fertilization with similar estrous cycle. If cloned embryos with 2~4 cell stage are transferred, they must be transferred into oviducts in periovulatory stage. Number and deposition sites of transferred cloned embryos are important. And we must compare the methods of ET between surgical and non-surgical ones in respect of production efficiency. Sow recipients after natural estrus is most preferred recipients however its cost is must be considered. Here we will review many of current studies about porcine embryo transfer to increase production efficiency of transgenic pigs and strategies for further studies.

Malondialdehyde Level by Ethanol Exposure in Mouse According to the ALDH2 Enzyme Activity

  • Lee, Chung-Jong;Kim, Yong-Dae;Kim, Sung-Hoon;Eom, Sang-Yong;Zhang, Yan Wei;Kim, Heon
    • Biomedical Science Letters
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    • v.14 no.1
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    • pp.13-18
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    • 2008
  • Excessive alcohol consumption is associated with increased risks of many diseases including cancer. Individuals who regularly consume excessive quantities of alcohol have a greater risk of developing head and neck cancers such as esophageal, pharyngeal and oral cavity cancers if they are deficient in ALDH2 expression compared to normal populations. We evaluated lipid peroxidation in Aldh2 +/+ and Aldh2 -/- mice after they had been subjected to acute ethanol exposure. Malondialdehyde(MDA) level in liver tissue was evaluated as a biomarker of oxidative lipid peroxidation. Although the ethanol treatment did not increase the hepatic MDA level both in Aldh2 +/+ mice and in Aldh2 -/- mice, the MDA level was significant higher in the Aldh2 -/- mice than in the Aldh2 +/+ group. The MDA level was also significantly correlated with olive tail moment in blood and the level of 8-OHdG in liver tissue. This is a strong evidence to support our hypothesis that oxidative stress is more intense in Aldh2 -/- mice than in Aldh2 +/+ mice. Our results suggest that ALDH2-deficient individuals may be more susceptible than wild-type ALDH2 individuals to ethanol-mediated liver disease, including cancer.

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Functional Genomic Approaches Using the Nematode Caenorhabditis elegans as a Model System

  • Lee, Jun-Ho;Nam, Seung-Hee;Hwang, Soon-Baek;Hong, Min-Gi;Kwon, Jae-Young;Joeng, Kyu-Sang;Im, Seol-Hee;Shim, Ji-Won;Park, Moon-Cheol
    • BMB Reports
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    • v.37 no.1
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    • pp.107-113
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    • 2004
  • Since the completion of the genome project of the nematode C. elegans in 1998, functional genomic approaches have been applied to elucidate the gene and protein networks in this model organism. The recent completion of the whole genome of C. briggsae, a close sister species of C. elegans, now makes it possible to employ the comparative genomic approaches for identifying regulatory mechanisms that are conserved in these species and to make more precise annotation of the predicted genes. RNA interference (RNAi) screenings in C. elegans have been performed to screen the whole genome for the genes whose mutations give rise to specific phenotypes of interest. RNAi screens can also be used to identify genes that act genetically together with a gene of interest. Microarray experiments have been very useful in identifying genes that exhibit co-regulated expression profiles in given genetic or environmental conditions. Proteomic approaches also can be applied to the nematode, just as in other species whose genomes are known. With all these functional genomic tools, genetics will still remain an important tool for gene function studies in the post genome era. New breakthroughs in C. elegans biology, such as establishing a feasible gene knockout method, immortalized cell lines, or identifying viruses that can be used as vectors for introducing exogenous gene constructs into the worms, will augment the usage of this small organism for genome-wide biology.

Role of NADH: quinone oxidoreductase-1 in the tight junctions of colonic epithelial cells

  • Nam, Seung Taek;Hwang, Jung Hwan;Kim, Dae Hong;Park, Mi Jung;Lee, Ik Hwan;Nam, Hyo Jung;Kang, Jin Ku;Kim, Sung Kuk;Hwang, Jae Sam;Chung, Hyo Kyun;Shong, Minho;Lee, Chul-Ho;Kim, Ho
    • BMB Reports
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    • v.47 no.9
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    • pp.494-499
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    • 2014
  • NADH:quinone oxidoreductase 1 (NQO1) is known to be involved in the regulation of energy synthesis and metabolism, and the functional studies of NQO1 have largely focused on metabolic disorders. Here, we show for the first time that compared to NQO1-WT mice, NQO1-KO mice exhibited a marked increase of permeability and spontaneous inflammation in the gut. In the DSS-induced colitis model, NQO1-KO mice showed more severe inflammatory responses than NQO1-WT mice. Interestingly, the transcript levels of claudin and occludin, the major tight junction molecules of gut epithelial cells, were significantly decreased in NQO1-KO mice. The colons of NQO1-KO mice also showed high levels of reactive oxygen species (ROS) and histone deacetylase (HDAC) activity, which are known to affect transcriptional regulation. Taken together, these novel findings indicate that NQO1 contributes to the barrier function of gut epithelial cells by regulating the transcription of tight junction molecules.