1
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Stavreva DA, Varticovski L, Raziuddin R, Pegoraro G, Schiltz RL, Hager GL. Novel biosensor for high-throughput detection of progesterone receptor-interacting endocrine disruptors. Sci Rep 2024; 14:5567. [PMID: 38448539 PMCID: PMC10917811 DOI: 10.1038/s41598-024-55254-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/20/2024] [Indexed: 03/08/2024] Open
Abstract
Progesterone receptor (PR)-interacting compounds in the environment are associated with serious health hazards. However, methods for their detection in environmental samples are cumbersome. We report a sensitive activity-based biosensor for rapid and reliable screening of progesterone receptor (PR)-interacting endocrine disrupting chemicals (EDCs). The biosensor is a cell line which expresses nuclear mCherry-NF1 and a green fluorescent protein (GFP)-tagged chimera of glucocorticoid receptor (GR) N terminus fused to the ligand binding domain (LBD) of PR (GFP-GR-PR). As this LBD is shared by the PRA and PRB, the biosensor reports on the activation of both PR isoforms. This GFP-GR-PR chimera is cytoplasmic in the absence of hormone and translocates rapidly to the nucleus in response to PR agonists or antagonists in concentration- and time-dependent manner. In live cells, presence of nuclear NF1 label eliminates cell fixation and nuclear staining resulting in efficient screening. The assay can be used in screens for novel PR ligands and PR-interacting contaminants in environmental samples. A limited screen of river water samples indicated a widespread, low-level contamination with PR-interacting contaminants in all tested samples.
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Affiliation(s)
- Diana A Stavreva
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, 41 Medlars Dr., Bethesda, MD, 20892-5055, USA.
| | - Lyuba Varticovski
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, 41 Medlars Dr., Bethesda, MD, 20892-5055, USA
| | - Razi Raziuddin
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, 41 Medlars Dr., Bethesda, MD, 20892-5055, USA
| | - Gianluca Pegoraro
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, 41 Medlars Dr., Bethesda, MD, 20892-5055, USA
| | - R Louis Schiltz
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, 41 Medlars Dr., Bethesda, MD, 20892-5055, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, 41 Medlars Dr., Bethesda, MD, 20892-5055, USA.
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2
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Wu GY, Zheng XX, Zhao SL, Wang Y, Jiang S, Wang YS, Yi YL, Yao J, Wen HZ, Liu J, Li HL, Sui JF. The prelimbic cortex regulates itch processing by controlling attentional bias. iScience 2022; 26:105829. [PMID: 36619983 PMCID: PMC9816985 DOI: 10.1016/j.isci.2022.105829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 10/31/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Itch is a complex and unpleasant sensory experience. Recent studies have begun to investigate the neural mechanisms underlying the modulation of sensory and emotional components of itch in the brain. However, the key brain regions and neural mechanism involved in modulating the attentional processing of itch remain elusive. Here, we showed that the prelimbic cortex (PrL) is associated with itch processing and that the manipulation of itch-responsive neurons in the PrL significantly disrupted itch-induced scratching. Interestingly, we found that increasing attentional bias toward a distracting stimulus could disturb itch processing. We also demonstrated the existence of a population of attention-related neurons in the PrL that drive attentional bias to regulate itch processing. Importantly, itch-responsive neurons and attention-related neurons significantly overlapped in the PrL and were mutually interchangeable in the regulation of itch processing at the cellular activity level. Our results revealed that the PrL regulates itch processing by controlling attentional bias.
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Affiliation(s)
- Guang-Yan Wu
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Corresponding author
| | - Xiao-Xia Zheng
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Shan-Lan Zhao
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Yi Wang
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Shan Jiang
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Yi-Song Wang
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Yi-Lun Yi
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Juan Yao
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Hui-Zhong Wen
- Department of Neurobiology, College of Basic Medical Sciences, Chongqing Key Laboratory of Neurobiology, Army Medical University, Chongqing 400038, China
| | - Ju Liu
- Department of Foreign Languages, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Hong-Li Li
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Corresponding author
| | - Jian-Feng Sui
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Corresponding author
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3
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Sharma M, Mandal MK, Pandey S, Kumar R, Dubey KK. Visible-Light-Driven Photocatalytic Degradation of Tetracycline Using Heterostructured Cu 2O-TiO 2 Nanotubes, Kinetics, and Toxicity Evaluation of Degraded Products on Cell Lines. ACS OMEGA 2022; 7:33572-33586. [PMID: 36157782 PMCID: PMC9494644 DOI: 10.1021/acsomega.2c04576] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 09/01/2022] [Indexed: 05/30/2023]
Abstract
This study first reports on the tetracycline photodegradation with the synthesized heterostructured titanium oxide nanotubes coupled with cuprous oxide photocatalyst. The large surface area and more active sites on TiO2 nanotubes with a reduced band gap (coupling of Cu2O) provide faster photodegradation of tetracycline under visible light conditions. Cytotoxicity experiments performed on the RAW 264.7 (mouse macrophage) and THP-1 (human monocytes) cell lines of tetracycline and the photodegraded products of tetracycline as well as quenching experiments were also performed. The effects of different parameters like pH, photocatalyst loading concentration, cuprous oxide concentration, and tetracycline load on the photodegradation rate were investigated. With an enhanced surface area of nanotubes and a reduced band gap of 2.58 eV, 1.5 g/L concentration of 10% C-TAC showed the highest efficiency of visible-light-driven photodegradation (∼100% photodegradation rate in 60 min) of tetracycline at pH 5, 7, and 9. The photodegradation efficiency is not depleted up to five consecutive batch cycles. Quenching experiments confirmed that superoxide radicals and hydroxyl radicals are the most involved reactive species in the photodegradation of tetracycline, while valance band electrons are the least involved reactive species. The cytotoxicity percentage of tetracycline and its degraded products on RAW 264.7 (-0.932) as well as THP-1 (-0.931) showed a negative correlation with the degradation percentage with a p-value of 0.01. The toxicity-free effluent of photodegradation suggests the application of the synthesized photocatalyst in wastewater treatment.
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Affiliation(s)
- Manisha Sharma
- Department
of Biotechnology, Central University of
Haryana, Mahendergarh, Haryana 123031, India
| | - Mrinal Kanti Mandal
- Department
of Chemical Engineering, National Institute
of Technology, Durgapur, West Bengal 713209, India
| | - Shailesh Pandey
- Department
of Chemical Engineering, National Institute
of Technology, Durgapur, West Bengal 713209, India
| | - Ravi Kumar
- Department
of Biotechnology, Central University of
Haryana, Mahendergarh, Haryana 123031, India
| | - Kashyap Kumar Dubey
- Bioprocess
Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New
Delhi 110067, India
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4
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Mitochondrial GTP Links Nutrient Sensing to β Cell Health, Mitochondrial Morphology, and Insulin Secretion Independent of OxPhos. Cell Rep 2020; 28:759-772.e10. [PMID: 31315053 DOI: 10.1016/j.celrep.2019.06.058] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 02/15/2019] [Accepted: 06/14/2019] [Indexed: 12/18/2022] Open
Abstract
Mechanisms coordinating pancreatic β cell metabolism with insulin secretion are essential for glucose homeostasis. One key mechanism of β cell nutrient sensing uses the mitochondrial GTP (mtGTP) cycle. In this cycle, mtGTP synthesized by succinyl-CoA synthetase (SCS) is hydrolyzed via mitochondrial PEPCK (PEPCK-M) to make phosphoenolpyruvate, a high-energy metabolite that integrates TCA cycling and anaplerosis with glucose-stimulated insulin secretion (GSIS). Several strategies, including xenotopic overexpression of yeast mitochondrial GTP/GDP exchanger (GGC1) and human ATP and GTP-specific SCS isoforms, demonstrated the importance of the mtGTP cycle. These studies confirmed that mtGTP triggers and amplifies normal GSIS and rescues defects in GSIS both in vitro and in vivo. Increased mtGTP synthesis enhanced calcium oscillations during GSIS. mtGTP also augmented mitochondrial mass, increased insulin granule number, and membrane proximity without triggering de-differentiation or metabolic fragility. These data highlight the importance of the mtGTP signal in nutrient sensing, insulin secretion, mitochondrial maintenance, and β cell health.
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5
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Kumar P, Nagarajan A, Uchil PD. Introducing Genes into Cultured Mammalian Cells. Cold Spring Harb Protoc 2019; 2019:pdb.top095406. [PMID: 31285274 DOI: 10.1101/pdb.top095406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Strategies for the delivery of genes into eukaryotic cells fall into three categories: transfection by biochemical methods, transfection by physical methods, and virus-mediated transduction. This introduction deals with the first two categories.
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6
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Abstract
Large-scale sequencing of human tumours has uncovered a vast array of genomic alterations. Genetically engineered mouse models recapitulate many features of human cancer and have been instrumental in assigning biological meaning to specific cancer-associated alterations. However, their time, cost and labour-intensive nature limits their broad utility; thus, the functional importance of the majority of genomic aberrations in cancer remains unknown. Recent advances have accelerated the functional interrogation of cancer-associated alterations within in vivo models. Specifically, the past few years have seen the emergence of CRISPR-Cas9-based strategies to rapidly generate increasingly complex somatic alterations and the development of multiplexed and quantitative approaches to ascertain gene function in vivo.
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7
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A Comparison of Inducible Gene Expression Platforms: Implications for Recombinant Adeno-Associated Virus (rAAV) Vector-Mediated Ocular Gene Therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1185:79-83. [PMID: 31884592 DOI: 10.1007/978-3-030-27378-1_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
The ability to temporally control levels of a therapeutic protein in vivo is vital for the development of safe and efficacious gene therapy treatments for autosomal dominant or complex retinal diseases, where uncontrolled transgene overexpression may lead to deleterious off-target effects and accelerated disease progression. While numerous platforms exist that allow for modulation of gene expression levels - ranging from inducible promoters to destabilizing domains - many have drawbacks that make them less than ideal for use in recombinant adeno-associated virus (rAAV) vectors, which over the past two decades have become the mainstay technology for mediating gene delivery to the retina. Herein, we discuss the advantages and disadvantages of three major gene expression platforms with regard to their suitability for ocular gene therapy applications.
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8
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Bryk J, Reeves RG, Reed FA, Denton JA. Transcriptional effects of a positive feedback circuit in Drosophila melanogaster. BMC Genomics 2017; 18:990. [PMID: 29281970 PMCID: PMC5746007 DOI: 10.1186/s12864-017-4385-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 12/15/2017] [Indexed: 01/24/2023] Open
Abstract
Background Synthetic systems that use positive feedback have been developed to control human disease vectors and crop pests. The tTAV system, which has been deployed in several insect species, relies on a positive feedback circuit that can be inhibited via dietary tetracycline. Although insects carrying tTAV fail to survive until adulthood in the absence of tetracycline, the exact reason for its lethality, as well as the transcriptomic effects of an active positive feedback circuit, remain unknown. Results We engineered the tTAV system in Drosophila melanogaster and investigated the effects of tTAV genome integration locus on the whole fly transcriptome during larval and adult life stages in four transgenic fly strains using gene expression microarrays. We found that while there were widespread effects on the transcriptome, the gene expression differences after removal of tetracycline were not consistent between integration sites. No specific region of the genome was affected, no common set of genes or pathways, nor did the integration site affect the transcripts in cis. Conclusion Although the positive feedback tTAV system is effective at killing insect larvae regardless of where it is inserted in the genome, it does not exhibit a specific, consistent transcriptional signature. Instead, each insertion site is associated with broad, but different, transcriptional effects. Our results suggest that lethality may not be caused by a direct effect on transcription of a set of key genes or pathways. Instead, we propose that rather than a specific action of a tTAV protein, it is the stochastic transcriptional effects specific to each insertion site that contribute to the tTAV-induced mortality. Electronic supplementary material The online version of this article (10.1186/s12864-017-4385-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jarosław Bryk
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany.,School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, UK
| | - R Guy Reeves
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Floyd A Reed
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany.,Department of Biology, University of Hawai'i at Mānoa, Hawai'i, Honolulu, 96822, USA
| | - Jai A Denton
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany. .,Genomics & Regulatory Systems Unit, Okinawa Institute for Science & Technology Graduate University, Onna-son, Okinawa, Japan.
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9
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Jenson LJ, Sun B, Bloomquist JR. Voltage-sensitive potassium channels expressed after 20-Hydroxyecdysone treatment of a mosquito cell line. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 87:75-80. [PMID: 28668511 DOI: 10.1016/j.ibmb.2017.06.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 06/24/2017] [Accepted: 06/26/2017] [Indexed: 06/07/2023]
Abstract
The goal of this research was to express receptors and ion channels in hormone-treated insect cell lines. Treatment of Anopheles gambiae Sua1B cells with 20-hydroxyecdysone showed an inhibition of cell growth over a time course of three days, with no change in cellular morphology. The effect of 20-hydroxyecdysone was enhanced in the presence of the potassium channel blocker 4-aminopyridine, but not tetraethylammonium. Concentration-response curves of 4-aminopyridine in the presence of 42 μM (1 mg/ml) 20-hydroxyecdysone showed similar IC50 values (6-10 μM) across 3 day exposures. Whole cell patch clamp confirmed the expression of delayed-rectifier (Kv2) potassium channels in hormone-supplemented Sua1B cells, whereas untreated Sua1B cells showed no evidence of Kv2 expression. The hormone-induced expression of Kv2 channels occurred in as little as 4 h after treatment, but were not observed after 24 h of exposure to 20-hydroxyecdysone, suggesting they played a role in cell death. The expressed channels had current-voltage relationships diagnostic for the Kv2 subtype, and were inhibited with an IC50 = 13 mM of tetraethylammonium. Overall, these parameters were similar to Anopheles gambiae Kv2 potassium channels expressed in HEK-293 cells. The induced presence of ion channels (and possibly receptors) in these cells has potential utility for high throughput screening and basic neuroscience research.
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Affiliation(s)
- Lacey J Jenson
- Emerging Pathogens Institute, Department of Entomology and Nematology, University of Florida, Gainesville, FL, 32601, USA; Bedoukian Research Inc., 21 Finance Drive, Danbury, CT, 06810, USA
| | - Baonan Sun
- Emerging Pathogens Institute, Department of Entomology and Nematology, University of Florida, Gainesville, FL, 32601, USA
| | - Jeffrey R Bloomquist
- Emerging Pathogens Institute, Department of Entomology and Nematology, University of Florida, Gainesville, FL, 32601, USA.
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10
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Isaac R, Vinik Y, Boura-Halfon S, Farack L, Streim S, Elhanany E, Kam Z, Zick Y. Prolonged Elimination of Negative Feedback Control Mechanisms Along the Insulin Signaling Pathway Impairs β-Cell Function In Vivo. Diabetes 2017; 66:1879-1889. [PMID: 28424159 DOI: 10.2337/db16-0827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 04/06/2017] [Indexed: 11/13/2022]
Abstract
Cellular stress and proinflammatory cytokines induce phosphorylation of insulin receptor substrate (IRS) proteins at Ser sites that inhibit insulin and IGF-I signaling. We therefore examined the effects of mutation of five "inhibitory" Ser phosphorylation sites on IRS2 function in transgenic mice that overexpress, selectively in pancreatic β-cells, either wild-type (WT) or a mutated IRS2 protein (IRS25A). Islets size, number, and mRNA levels of catalase and superoxide dismutase were increased, whereas those of nitric oxide synthase were decreased, in 7- to 10-week-old IRS25A-β mice compared with IRS2WT-β mice. However, glucose homeostasis and insulin secretion in IRS25A-β mice were impaired when compared with IRS2WT-β mice or to nontransgenic mice. This was associated with reduced mRNA levels of Glut2 and islet β-cell transcription factors such as Nkx6.1 and MafA Similarly, components mediating the unfolded protein response were decreased in islets of IRS25A-β mice in accordance with their decreased insulin secretion. The beneficial effects of IRS25A on β-cell proliferation and β-cell transcription factors were evident only in 5- to 8-day-old mice. These findings suggest that elimination of inhibitory Ser phosphorylation sites of IRS2 exerts short-term beneficial effects in vivo; however, their sustained elimination leads to impaired β-cell function.
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Affiliation(s)
- Roi Isaac
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yaron Vinik
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Sigalit Boura-Halfon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Lydia Farack
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Sarina Streim
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Eytan Elhanany
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Zvi Kam
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yehiel Zick
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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11
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Okuma K, Fukagawa K, Kohma T, Takahama Y, Hamaguchi Y, Ito M, Tanaka Y, Buonocore L, Rose JK, Hamaguchi I. A recombinant vesicular stomatitis virus encoding CCR5-tropic HIV-1 receptors targets HIV-1-infected cells and controls HIV-1 infection. Microbes Infect 2016; 19:277-287. [PMID: 28025070 DOI: 10.1016/j.micinf.2016.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/15/2016] [Accepted: 12/18/2016] [Indexed: 11/29/2022]
Abstract
Anti-retroviral therapy is useful to treat human immunodeficiency virus type 1 (HIV-1)-infected individuals, but has some major problems, such as the generation of multidrug-resistant viruses. To develop a novel supplemental or alternative therapeutic for CCR5-tropic (R5) HIV-1 infection, we generated a recombinant vesicular stomatitis virus (rVSV) in which the gene encoding its envelope glycoprotein (G) was replaced with the genes encoding R5 HIV-1 receptors (human CD4 and CCR5), designated VSVΔG-CC5. Our present data demonstrate that this rVSV specifically infects cells that are transiently expressing R5 HIV-1 envelope glycoproteins, but does not infect those expressing CXCR4-tropic HIV-1 envelope glycoproteins. Notably, after a CD4+CCR5+ T cell line or primary cells initially infected with R5 HIV-1 were inoculated with G-complemented VSVΔG-CC5, the rVSV significantly reduced the number of HIV-1-infected cells, probably through direct targeting of the rVSV and VSV-mediated cytolysis and/or through syncytium formation- or cell-cell fusion-dependent killing, and markedly inhibited HIV-1 production. Furthermore, G-complemented VSVΔG-CC5 also efficiently inhibited HIV-1 infection in R5 HIV-1-infected humanized immunodeficient mice. Taken together, our findings indicate that a cytolytic rVSV that targets and eliminates R5 HIV-1-infected cells potentially has therapeutic value for controlling R5 HIV-1 infection.
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Affiliation(s)
- Kazu Okuma
- Department of Safety Research on Blood and Biological Products, National Institute of Infectious Diseases, Tokyo, Japan.
| | - Koji Fukagawa
- Department of Safety Research on Blood and Biological Products, National Institute of Infectious Diseases, Tokyo, Japan; Technology and Product Development Division, Diagnostic Reagent Development, Sysmex Corporation, Kobe, Japan
| | - Takuya Kohma
- Department of Safety Research on Blood and Biological Products, National Institute of Infectious Diseases, Tokyo, Japan; Technology and Product Development Division, Diagnostic Reagent Development, Sysmex Corporation, Kobe, Japan
| | - Youichi Takahama
- Technology and Product Development Division, Diagnostic Reagent Development, Sysmex Corporation, Kobe, Japan
| | - Yukio Hamaguchi
- Technology and Product Development Division, Diagnostic Reagent Development, Sysmex Corporation, Kobe, Japan
| | - Mamoru Ito
- Central Institute of Experimental Animals, Kanagawa, Japan
| | - Yuetsu Tanaka
- Department of Immunology, Graduate School and Faculty of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Linda Buonocore
- Department of Pathology, Yale University School of Medicine, CT, USA
| | - John K Rose
- Department of Pathology, Yale University School of Medicine, CT, USA
| | - Isao Hamaguchi
- Department of Safety Research on Blood and Biological Products, National Institute of Infectious Diseases, Tokyo, Japan
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12
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Brahmachari S, Ge P, Lee SH, Kim D, Karuppagounder SS, Kumar M, Mao X, Shin JH, Lee Y, Pletnikova O, Troncoso JC, Dawson VL, Dawson TM, Ko HS. Activation of tyrosine kinase c-Abl contributes to α-synuclein-induced neurodegeneration. J Clin Invest 2016; 126:2970-88. [PMID: 27348587 PMCID: PMC4966315 DOI: 10.1172/jci85456] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 05/05/2016] [Indexed: 12/20/2022] Open
Abstract
Aggregation of α-synuclein contributes to the formation of Lewy bodies and neurites, the pathologic hallmarks of Parkinson disease (PD) and α-synucleinopathies. Although a number of human mutations have been identified in familial PD, the mechanisms that promote α-synuclein accumulation and toxicity are poorly understood. Here, we report that hyperactivity of the nonreceptor tyrosine kinase c-Abl critically regulates α-synuclein-induced neuropathology. In mice expressing a human α-synucleinopathy-associated mutation (hA53Tα-syn mice), deletion of the gene encoding c-Abl reduced α-synuclein aggregation, neuropathology, and neurobehavioral deficits. Conversely, overexpression of constitutively active c-Abl in hA53Tα-syn mice accelerated α-synuclein aggregation, neuropathology, and neurobehavioral deficits. Moreover, c-Abl activation led to an age-dependent increase in phosphotyrosine 39 α-synuclein. In human postmortem samples, there was an accumulation of phosphotyrosine 39 α-synuclein in brain tissues and Lewy bodies of PD patients compared with age-matched controls. Furthermore, in vitro studies show that c-Abl phosphorylation of α-synuclein at tyrosine 39 enhances α-synuclein aggregation. Taken together, this work establishes a critical role for c-Abl in α-synuclein-induced neurodegeneration and demonstrates that selective inhibition of c-Abl may be neuroprotective. This study further indicates that phosphotyrosine 39 α-synuclein is a potential disease indicator for PD and related α-synucleinopathies.
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Affiliation(s)
- Saurav Brahmachari
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
| | - Preston Ge
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
| | - Su Hyun Lee
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Donghoon Kim
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Diana Helis Henry Medical Research Foundation, New Orleans, Louisiana, USA
| | - Senthilkumar S. Karuppagounder
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
| | - Manoj Kumar
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
| | - Xiaobo Mao
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
| | - Joo Ho Shin
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
| | - Yunjong Lee
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
| | | | - Juan C. Troncoso
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Pathology, Division of Neuropathology
| | - Valina L. Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
- Department of Physiology
- Solomon H. Snyder Department of Neuroscience, and
| | - Ted M. Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana, USA
- Solomon H. Snyder Department of Neuroscience, and
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Han Seok Ko
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, and
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Diana Helis Henry Medical Research Foundation, New Orleans, Louisiana, USA
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Esmaeili M, Jennek S, Ludwig S, Klitzsch A, Kraft F, Melle C, Baniahmad A. The tumor suppressor ING1b is a novel corepressor for the androgen receptor and induces cellular senescence in prostate cancer cells. J Mol Cell Biol 2016; 8:207-20. [PMID: 26993046 DOI: 10.1093/jmcb/mjw007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/10/2015] [Indexed: 12/28/2022] Open
Abstract
The androgen receptor (AR) signaling is critical for prostate cancer (PCa) progression to the castration-resistant stage with poor clinical outcome. Altered function of AR-interacting factors may contribute to castration-resistant PCa (CRPCa). Inhibitor of growth 1 (ING1) is a tumor suppressor that regulates various cellular processes including cell proliferation. Interestingly, ING1 expression is upregulated in senescent primary human prostate cells; however, its role in AR signaling in PCa was unknown. Using a proteomic approach by surface-enhanced laser desorption ionization-mass spectrometry (SELDI-MS) combined with immunological techniques, we provide here evidence that ING1b interacts in vivo with the AR. The interaction was confirmed by co-immunoprecipitation, in vitro GST-pull-down, and quantitative intracellular colocalization analyses. Functionally, ING1b inhibits AR-responsive promoters and endogenous key AR target genes in the human PCa LNCaP cells. Conversely, ING1b knockout (KO) mouse embryonic fibroblasts (MEFs) exhibit enhanced AR activity, suggesting that the interaction with ING1b represses the AR-mediated transcription. Also, data suggest that ING1b expression is downregulated in CRPCa cells compared with androgen-dependent LNCaP cells. Interestingly, its ectopic expression induces cellular senescence and reduces cell migration in both androgen-dependent and CRPCa cells. Intriguingly, ING1b can also inhibit androgen-induced growth in LNCaP cells in a similar manner as AR antagonists. Moreover, ING1b upregulates different cell cycle inhibitors including p27(KIP1), which is a novel target for ING1b. Taken together, our findings reveal a novel corepressor function of ING1b on various AR functions, thereby inhibiting PCa cell growth.
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Affiliation(s)
- Mohsen Esmaeili
- Institute of Human Genetics, Jena University Hospital, Jena, Germany
| | - Susanne Jennek
- Institute of Human Genetics, Jena University Hospital, Jena, Germany
| | - Susann Ludwig
- Institute of Human Genetics, Jena University Hospital, Jena, Germany
| | | | - Florian Kraft
- Institute of Human Genetics, Jena University Hospital, Jena, Germany
| | - Christian Melle
- Biomolecular Photonics Group, Jena University Hospital, Jena, Germany
| | - Aria Baniahmad
- Institute of Human Genetics, Jena University Hospital, Jena, Germany
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14
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Translating Lung Function Genome-Wide Association Study (GWAS) Findings. ADVANCES IN GENETICS 2016; 93:57-145. [DOI: 10.1016/bs.adgen.2015.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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15
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A53T human α-synuclein overexpression in transgenic mice induces pervasive mitochondria macroautophagy defects preceding dopamine neuron degeneration. J Neurosci 2015; 35:890-905. [PMID: 25609609 DOI: 10.1523/jneurosci.0089-14.2015] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
In vitro evidence suggests that the inefficient removal of damaged mitochondria by macroautophagy contributes to Parkinson's disease (PD). Using a tissue-specific gene amplification strategy, we generated a transgenic mouse line with human α-synuclein A53T overexpression specifically in dopamine (DA) neurons. Transgenic mice showed profound early-onset mitochondria abnormalities, characterized by macroautophagy marker-positive cytoplasmic inclusions containing mainly mitochondrial remnants, which preceded the degeneration of DA neurons. Genetic deletion of either parkin or PINK1 in these transgenic mice significantly worsened mitochondrial pathologies, including drastically enlarged inclusions and loss of total mitochondria contents. These data suggest that mitochondria are the main targets of α-synuclein and their defective autophagic clearance plays a significant role during pathogenesis. Moreover, endogenous PINK1 or parkin is indispensable for the proper autophagic removal of damaged mitochondria. Our data for the first time establish an essential link between mitochondria macroautophagy impairments and DA neuron degeneration in an in vivo model based on known PD genetics. The model, its well-defined pathologies, and the demonstration of a main pathogenesis pathway in the present study have set the stage and direction of emphasis for future studies.
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16
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Abstract
The majority of human breast cancers are estrogen receptor-positive (ER+), but this has proven challenging to model in genetically engineered mice. This review summarizes information on 21 mouse models that develop ER+ mammary cancer. Where available, information on cancer pathology and gene expression profiles is referenced to assist in understanding which histological subtype of ER+ human cancer each model might represent. ESR1, CCDN1, prolactin, TGFα, AIB1, ESPL1, and WNT1 overexpression, PIK3CA gain of function, as well as loss of P53 (Trp53) or STAT1 are associated with ER+ mammary cancer. Treatment with the PPARγ agonist efatutazone in a mouse with Brca1 and p53 deficiency and 7,12-dimethylbenz(a)anthracene exposure in combination with an activated myristoylated form of AKT1 also induce ER+ mammary cancer. A spontaneous mutant in nude mice that develops metastatic ER+ mammary cancer is included. Age of cancer development ranges from 3 to 26 months and the percentage of cancers that are ER+ vary from 21 to 100%. Not all models are characterized as to their estrogen dependency and/or response to anti-hormonal therapy. Strain backgrounds include C57Bl/6, FVB, BALB/c, 129S6/SvEv, CB6F1, and NIH nude. Most models have only been studied on one strain background. In summary, while a range of models are available for studies of pathogenesis and therapy of ER+ breast cancers, many could benefit from further characterization, and opportunity for development of new models remains.
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Affiliation(s)
- Sarah A. Dabydeen
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia, USA 20057
| | - Priscilla A. Furth
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia, USA 20057
- Department of Medicine, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia, USA 20057
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17
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Yang T, Burrows C, Park JH. Development of a doxycycline-inducible lentiviral plasmid with an instant regulatory feature. Plasmid 2014; 72:29-35. [PMID: 24727543 DOI: 10.1016/j.plasmid.2014.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 03/23/2014] [Accepted: 04/01/2014] [Indexed: 12/19/2022]
Abstract
Lentiviruses provide highly efficient gene delivery vehicles in both dividing and non-dividing cells. Inducible gene expression systems often employ a specific cell line that constitutively expresses a regulatory protein for transgene expression. As one of such inducible expression systems the Tet-On system uses a cell line expressing reverse tetracycline-responsive transcriptional activator (rtTA). The rtTA protein binds to the tetracycline-responsive element (TRE) in the promoter and activates transcription of a transgene in a doxycycline-dependent manner. To establish a universal and instant regulatory system without generating Tet-On cell lines, the cDNAs of rtTA and a testing target gene (PPM1B) were cloned in the bi-directional TRE-containing promoters. Here, we examined whether a basal leaky expression of rtTA allows instantly inducible expression of both rtTA itself and the target gene, PPM1B in a single plasmid using the two mini-CMV promoters. Transient transfection of the lentiviral plasmids into human embryonic kidney HEK293T cells showed a significant induction of PPM1B expression in response to doxycycline, suggesting that these lentiviral plasmids can be used as an instantly inducible mammalian expression vector. However, the expression of rtTA by lentiviral transduction shows a minimal expression without a consistent response to doxycycline, suggesting that the utility of these lentiviral vectors is limited. A potential solution to overcome lentiviral transgene inactivation is proposed.
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Affiliation(s)
- Tian Yang
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand; Institute of Somatology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu 210029, PR China
| | - Christopher Burrows
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Jeong Hyeon Park
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
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18
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Thomas DC, Wong FS, Zaccone P, Green EA, Wållberg M. Protection of islet grafts through transforming growth factor-β-induced tolerogenic dendritic cells. Diabetes 2013; 62:3132-42. [PMID: 23715623 PMCID: PMC3749342 DOI: 10.2337/db12-1740] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In type 1 diabetes, the insulin-producing β-cells are destroyed by the immune system. One way of restoring glucose control is to transplant β-cells from a donor. Although this procedure may restore endogenous insulin production, immunosuppressive treatment is needed to prevent the recipient from rejecting the donor-derived islets. We investigated the possibilities of transient expression of the immunosuppressive cytokine transforming growth factor (TGF)-β within islets to achieve long-term graft tolerance. We found that brief expression of TGF-β prevented rejection of syngeneic islets, that there was reduction of dendritic cell (DC) activation in the graft, and that there was reduced reactivation of T cells in the graft-draining lymph nodes. In vitro exposure of bone marrow-derived DCs to TGF-β reduced expression of costimulatory molecules CD80 and CD86, as well as production of proinflammatory cytokines such as interleukin-12 p70 in DCs, but did not alter levels of major histocompatibility complex classes I and II. Furthermore, the capacity of TGF-β-treated bone marrow-derived DCs to activate both CD4(+) and CD8(+) T cells was reduced. Adding TGF-β-conditioned tolerogenic DCs to the grafted islets led to long-term survival of the graft, demonstrating that TGF-β-induced tolerogenic DCs can provide an effective means to restore immune tolerance in an already established autoimmune disease.
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Affiliation(s)
- David C. Thomas
- Cambridge Institute for Medical Research, Addenbrooke’s Hospital, Cambridge, U.K
| | - F. Susan Wong
- Diabetes Research Group, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff, U.K
| | - Paola Zaccone
- Department of Pathology, University of Cambridge, Cambridge, U.K
| | - E. Allison Green
- Centre for Immunology and Infection, Hull York Medical School and the Department of Biology, University of York, York, U.K
- Corresponding authors: E. Allison Green, , and Maja Wållberg,
| | - Maja Wållberg
- Cambridge Institute for Medical Research, Addenbrooke’s Hospital, Cambridge, U.K
- Corresponding authors: E. Allison Green, , and Maja Wållberg,
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19
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Zhang Y, Sicot G, Cui X, Vogel M, Wuertzer CA, Lezon-Geyda K, Wheeler J, Harki DA, Muzikar KA, Stolper DA, Dervan PB, Perkins AS. Targeting a DNA binding motif of the EVI1 protein by a pyrrole-imidazole polyamide. Biochemistry 2011; 50:10431-41. [PMID: 22039883 PMCID: PMC3619939 DOI: 10.1021/bi200962u] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The zinc finger protein EVI1 is causally associated with acute myeloid leukemogenesis, and inhibition of its function with a small molecule therapeutic may provide effective therapy for EVI1-expressing leukemias. In this paper we describe the development of a pyrrole-imidazole polyamide to specifically block EVI1 binding to DNA. We first identify essential domains for leukemogenesis through structure-function studies on both EVI1 and the t(3;21)(q26;q22)-derived RUNX1-MDS1-EVI1 (RME) protein, which revealed that DNA binding to the cognate motif GACAAGATA via the first of two zinc finger domains (ZF1, encompassing fingers 1-7) is essential transforming activity. To inhibit DNA binding via ZF1, we synthesized a pyrrole-imidazole polyamide 1, designed to bind to a subsite within the GACAAGATA motif and thereby block EVI1 binding. DNase I footprinting and electromobility shift assays revealed a specific and high affinity interaction between polyamide 1 and the GACAAGATA motif. In an in vivo CAT reporter assay using NIH-3T3-derived cell line with a chromosome-embedded tet-inducible EVI1-VP16 as well as an EVI1-responsive reporter, polyamide 1 completely blocked EVI1-responsive reporter activity. Growth of a leukemic cell line bearing overexpressed EVI1 was also inhibited by treatment with polyamide 1, while a control cell line lacking EVI1 was not. Finally, colony formation by RME was attenuated by polyamide 1 in a serial replating assay. These studies provide evidence that a cell permeable small molecule may effectively block the activity of a leukemogenic transcription factor and provide a valuable tool to dissect critical functions of EVI1 in leukemogenesis.
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Affiliation(s)
- Yi Zhang
- Department of Pathology and Lab Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, New York 14642, United States
| | - Géraldine Sicot
- Department of Pathology and Lab Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, New York 14642, United States
| | - Xiaohui Cui
- Department of Pathology and Lab Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, New York 14642, United States
| | - Marion Vogel
- Department of Pathology and Lab Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, New York 14642, United States
| | - Charles A. Wuertzer
- Department of Pathology and Lab Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, New York 14642, United States
| | - Kimberly Lezon-Geyda
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut 06510, United States
| | - John Wheeler
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut 06510, United States
| | - Daniel A. Harki
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Katy A. Muzikar
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | | | - Peter B. Dervan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Archibald S. Perkins
- Department of Pathology and Lab Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, New York 14642, United States
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20
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Xu HP, Furman M, Mineur YS, Chen H, King SL, Zenisek D, Zhou ZJ, Butts DA, Tian N, Picciotto MR, Crair MC. An instructive role for patterned spontaneous retinal activity in mouse visual map development. Neuron 2011; 70:1115-27. [PMID: 21689598 DOI: 10.1016/j.neuron.2011.04.028] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/05/2011] [Indexed: 10/18/2022]
Abstract
Complex neural circuits in the mammalian brain develop through a combination of genetic instruction and activity-dependent refinement. The relative role of these factors and the form of neuronal activity responsible for circuit development is a matter of significant debate. In the mammalian visual system, retinal ganglion cell projections to the brain are mapped with respect to retinotopic location and eye of origin. We manipulated the pattern of spontaneous retinal waves present during development without changing overall activity levels through the transgenic expression of β2-nicotinic acetylcholine receptors in retinal ganglion cells of mice. We used this manipulation to demonstrate that spontaneous retinal activity is not just permissive, but instructive in the emergence of eye-specific segregation and retinotopic refinement in the mouse visual system. This suggests that specific patterns of spontaneous activity throughout the developing brain are essential in the emergence of specific and distinct patterns of neuronal connectivity.
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Affiliation(s)
- Hong-ping Xu
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA.
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21
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Fussenegger M, Moser S, Bailey JE. Regulated multicistronic expression technology for mammalian metabolic engineering. Cytotechnology 2011; 28:111-26. [PMID: 19003413 PMCID: PMC3449837 DOI: 10.1023/a:1008037916674] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Contemporary basic research is rapidly revealing increasingly complex molecular regulatory networks which are often interconnected via key signal integrators. These connections among regulatory and catalytic networks often frustrate bioengineers as promising metabolic engineering strategies are bypassed by compensatory metabolic responses or cause unexpected, undesired outcomes such as apoptosis, product protein degradation or inappropriate post- translational modification. Therefore, for metabolic engineering to achieve greater success in mammalian cell culture processes and to become important for future applications such as gene therapy and tissue engineering, this technology must be enhanced to allow simultaneous, in cases conditional, reshaping of metabolic pathways to access difficult-to-attain cell states. Recent advances in this new territory of multigene metabolic engineering are intimately linked to the development of multicistronic expression technology which allows the simultaneous, and in some cases, regulated expression of several genes in mammalian cells. Here we review recent achievements in multicistronic expression technology in view of multigene metabolic engineering.
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Affiliation(s)
- M Fussenegger
- Swiss Federal Institute of Technology, ETH Zurich, Institute of Biotechnology, CH-8093, Zurich, Switzerland
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22
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Liang FS, Ho WQ, Crabtree GR. Engineering the ABA plant stress pathway for regulation of induced proximity. Sci Signal 2011; 4:rs2. [PMID: 21406691 DOI: 10.1126/scisignal.2001449] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Chemically induced proximity (CIP) systems use small molecules and engineered proteins to control and study biological processes. However, small molecule-based systems for controlling protein abundance or activities have been limited by toxicity, instability, cost, and slow clearance of the small molecules in vivo. To address these problems, we modified proteins of the plant abscisic acid (ABA) stress response pathway to control the proximity of cellular proteins and showed that the system could be used to regulate transcription, signal transduction, and subcellular localization of proteins in response to exogenously applied ABA. We also showed that the ABA CIP system can be combined with other CIP systems to simultaneously control multiple processes. We found that, when given to mice, ABA was orally available and had a 4-hour half-life. These properties, along with its lack of toxicity and low cost, suggest that ABA may be well suited for therapeutic applications and as an experimental tool to control diverse cellular activities in vivo.
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Affiliation(s)
- Fu-Sen Liang
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
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23
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McKinney AJ, Holmen SL. Animal models of melanoma: a somatic cell gene delivery mouse model allows rapid evaluation of genes implicated in human melanoma. CHINESE JOURNAL OF CANCER 2011; 30:153-62. [PMID: 21352692 PMCID: PMC4013311 DOI: 10.5732/cjc.011.10007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 01/10/2011] [Accepted: 01/26/2011] [Indexed: 01/13/2023]
Abstract
The increasing incidence and mortality associated with advanced stages of melanoma are cause for concern. Few treatment options are available for advanced melanoma and the 5-year survival rate is less than 15%. Targeted therapies may revolutionize melanoma treatment by providing less toxic and more effective strategies. However, maximizing effectiveness requires further understanding of the molecular alterations that drive tumor formation, progression, and maintenance, as well as elucidating the mechanisms of resistance. Several different genetic alterations identified in human melanoma have been recapitulated in mice. This review outlines recent progress made in the development of mouse models of melanoma and summarizes what these findings reveal about the human disease. We begin with a discussion of traditional models and conclude with the recently developed RCAS/TVA somatic cell gene delivery mouse model of melanoma.
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Affiliation(s)
- Andrea J McKinney
- Department of Drug and Target Discovery, Nevada Cancer Institute, Las Vegas, NV 89135, USA
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24
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Tsuruno C, Okuma K, Takahashi Y, Tanaka R, Tanaka Y, Takahama Y, Hamaguchi Y, Hamaguchi I, Yamaguchi K. A recombinant vesicular stomatitis virus encoding HIV-1 receptors and human OX40 ligand efficiently eliminates HIV-1-infected CD4-positive T cells expressing OX40. Hum Immunol 2011; 72:295-304. [PMID: 21262309 DOI: 10.1016/j.humimm.2011.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 12/23/2010] [Accepted: 12/13/2010] [Indexed: 10/18/2022]
Abstract
OX40 protein is highly expressed on activated CD4-positive T cells that are susceptible for human immunodeficiency virus type 1 (HIV-1) infection. To target and kill HIV-1-infected OX40(+) T cells, we used a recombinant vesicular stomatitis virus (rVSV) lacking its envelope glycoprotein (ΔG) and instead expressing HIV-1 receptors CD4/CXCR4 and OX40 ligand (OX40L). Expression of OX40L as well as HIV-1 receptors on the VSV particles led to specific infection of OX40(+) T cells, including primary cells, either acutely or chronically infected with X4 HIV-1. Consequently, the rVSV rapidly eliminated these infected cells and caused a marked reduction of HIV-1 viral load in culture. Inclusion of the OX40L gene in the VSV recombinant led to significantly better infection and HIV-1 elimination compared with an rVSVΔG expressing only HIV-1 receptors. A novel rVSVΔG encoding both HIV-1 receptors and OX40L has a potentially greater therapeutic value than an rVSVΔG expressing only HIV-1 receptors.
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Affiliation(s)
- Chikayuki Tsuruno
- Department of Safety Research on Blood and Biological products, National Institute of Infectious Diseases, Tokyo, Japan
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25
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Paulose T, Hernández-Ochoa I, Basavarajappa MS, Peretz J, Flaws JA. Increased sensitivity of estrogen receptor alpha overexpressing antral follicles to methoxychlor and its metabolites. Toxicol Sci 2011; 120:447-59. [PMID: 21252393 DOI: 10.1093/toxsci/kfr011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Methoxychlor (MXC), an organochlorine pesticide, and its metabolites, mono-hydroxy MXC (MOH) and bis-hydroxy MXC (HPTE) are known ovarian toxicants and can cause inhibition of antral follicle growth. Since these chemicals bind to estrogen receptor alpha (ESR1), we hypothesized that ovaries overexpressing ESR1 (ESR1 OE) would be more susceptible to toxicity induced by MXC and its metabolites because the chemicals can bind to more ESR1 in the antral follicles. We cultured antral follicles from controls and ESR1 OE mouse ovaries with either the vehicle dimethylsulfoxide (DMSO), MXC, MOH, or HPTE. The data show that at 96 h, the cultured antral follicles from ESR1 OE antral follicles are more susceptible to toxicity induced by MXC, MOH, and HPTE because low doses of these chemicals cause follicle growth inhibition in ESR1 OE mice but not in control mice. On comparing gene expression levels of nuclear receptors in the cultured antral follicles of ESR1 OE and control follicles, we found differential messenger RNA (mRNA) expression of Esr1, estrogen receptor beta (Esr2), androgen receptor (Ar), progesterone receptor (Pr), and aryl hydrocarbon receptor (Ahr) between the genotypes. We also analyzed mRNA levels of Cyp3a41a, the enzyme metabolizing MOH and HPTE, in the cultured follicles and found that Cyp3a41a was significantly lower in DMSO-treated ESR1 OE follicles compared with controls. In ESR1 OE livers, we found that Cyp3a41a levels were significantly lower compared with control livers. Collectively, these data suggest that MXC and its metabolites cause differential gene expression in ESR1 OE mice compared with controls. The results also suggest that the increased sensitivity of ESR1 OE mouse ovaries to toxicity induced by MXC and its metabolites is due to low clearance of the metabolites by the liver and ovary.
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Affiliation(s)
- Tessie Paulose
- Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61802, USA
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26
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Wållberg M, Wong FS, Green EA. An islet-specific pulse of TGF-β abrogates CTL function and promotes β cell survival independent of Foxp3+ T cells. THE JOURNAL OF IMMUNOLOGY 2011; 186:2543-51. [PMID: 21217013 DOI: 10.4049/jimmunol.1002098] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Effective therapies that prevent chronic inflammation from developing into type 1 diabetes remain elusive. In this study, we show that expression of TGF-β for just 1 wk in inflamed islets of NOD mice significantly delays diabetes development. Time course studies demonstrated that the brief TGF-β pulse protects only if administered when extensive β cell destruction has occurred. Surprisingly, TGF-β-mediated protection is not linked to enhanced Foxp3(+) regulatory T cell activity or to decreased intrapancreatic presentation of islet Ags. Instead, TGF-β disables the transition of primed autoreactive CD8(+) T cells to cytotoxic effectors and decreases generation, or maintenance, of CD8(+) memory T cells within the pancreas, significantly impairing their diabetogenic capacity.
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Affiliation(s)
- Maja Wållberg
- Department of Pathology, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge, United Kingdom
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27
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Sinclair P, Bian Q, Plutz M, Heard E, Belmont AS. Dynamic plasticity of large-scale chromatin structure revealed by self-assembly of engineered chromosome regions. ACTA ACUST UNITED AC 2010; 190:761-76. [PMID: 20819934 PMCID: PMC2935575 DOI: 10.1083/jcb.200912167] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Interphase chromatin compaction well above the 30-nm fiber is well documented, but the structural motifs underlying this level of chromatin folding remain unknown. Taking a reductionist approach, we analyzed in mouse embryonic stem (ES) cells and ES-derived fibroblasts and erythroblasts the folding of 10-160-megabase pair engineered chromosome regions consisting of tandem repeats of bacterial artificial chromosomes (BACs) containing approximately 200 kilobases of mammalian genomic DNA tagged with lac operator (LacO) arrays. Unexpectedly, linear mitotic and interphase chromatid regions formed from noncontiguously folded DNA topologies. Particularly, in ES cells, these model chromosome regions self-organized with distant sequences segregating into functionally distinct, compact domains. Transcriptionally active and histone H3K27me3-modified regions positioned toward the engineered chromosome subterritory exterior, with LacO repeats and the BAC vector backbone localizing within an H3K9me3, HP1-enriched core. Differential compaction of Dhfr and alpha- and beta-globin transgenes was superimposed on dramatic, lineage-specific reorganization of large-scale chromatin folding, demonstrating a surprising plasticity of large-scale chromatin organization.
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Affiliation(s)
- Paul Sinclair
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801, USA
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28
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Heath J, Abdelmageed Y, Braden TD, Williams CS, Williams JW, Paulose T, Hernandez-Ochoa I, Gupta R, Flaws JA, Goyal HO. Genetically induced estrogen receptor α mRNA (Esr1) overexpression does not adversely affect fertility or penile development in male mice. ACTA ACUST UNITED AC 2010; 32:282-94. [PMID: 20930192 DOI: 10.2164/jandrol.110.010769] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previously, we reported that estrogen receptor α mRNA (Esr1) or protein (ESR1) overexpression resulting from neonatal exposure to estrogens in rats was associated with infertility and maldeveloped penis characterized by reduced length and weight and abnormal accumulation of fat cells. The objective of this study was to determine if mutant male mice overexpressing Esr1 are naturally infertile or have reduced fertility and/or develop abnormal penis. The fertility parameters, including fertility and fecundity indices, numbers of days from the day of cohabitation to the day of delivery, and numbers of pups per female, were not altered from controls as a result of Esr1 overexpression. Likewise, penile morphology, including the length, weight, and diameter and os penis development, was not altered from controls. Conversely, weights of the seminal vesicles and bulbospongiosus and levator ani (BS/LA) muscles were significantly (P < .05) lower as compared with controls; however, the weight of the testis, the morphology of the testis and epididymis, and the plasma and testicular testosterone concentration were not different from controls. Hence, genetically induced Esr1 overexpression alone, without an exogenous estrogen exposure during the neonatal period, is unable to adversely affect the development of the penis as well as other male reproductive organs, except for limited, but significant, reductions in weights of the seminal vesicles and BS/LA muscles.
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Affiliation(s)
- John Heath
- Department of Biomedical Sciences, College of Veterinary Medicine, Tuskegee University, Tuskegee, AL, USA
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Hackl H, Rommer A, Konrad TA, Nassimbeni C, Wieser R. Tetracycline regulator expression alters the transcriptional program of mammalian cells. PLoS One 2010; 5:e13013. [PMID: 20886048 PMCID: PMC2945318 DOI: 10.1371/journal.pone.0013013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 09/03/2010] [Indexed: 11/19/2022] Open
Abstract
Background Tetracycline regulated ectopic gene expression is a widely used tool to study gene function. However, the tetracycline regulator (tetR) itself has been reported to cause certain phenotypic changes in mammalian cells. We, therefore, asked whether human myeloid U937 cells expressing the tetR in an autoregulated manner would exhibit alterations in gene expression upon removal of tetracycline. Methodology/Principal Findings Microarray analyses revealed that 172 and 774 unique genes were significantly differentially expressed by at least 2- or 1.5-fold, respectively, when tetR expressing U937 cells were maintained in media with or without the antibiotic. Conclusions/Significance These alterations in gene expression are likely to contribute to the phenotypic consequences of tetR expression. In addition, they need to be taken into consideration when using the tetR system for the identification of target genes of transcription factors or other genes of interest.
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Affiliation(s)
- Hubert Hackl
- Biocenter, Section for Bioinformatics, Innsbruck Medical University, Innsbruck, Austria
| | - Anna Rommer
- Clinic of Medicine I, Medical University of Vienna, Vienna, Austria
- Institute of Human Genetics, Medical University of Vienna, Vienna, Austria
| | - Torsten A. Konrad
- Institute of Human Genetics, Medical University of Vienna, Vienna, Austria
| | | | - Rotraud Wieser
- Clinic of Medicine I, Medical University of Vienna, Vienna, Austria
- Institute of Human Genetics, Medical University of Vienna, Vienna, Austria
- * E-mail:
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Souza DS, Spencer DM, Salles TSI, Salomão MA, Payen E, Beuzard Y, Carvalho HF, Costa FF, Saad STO. Death switch for gene therapy: application to erythropoietin transgene expression. Braz J Med Biol Res 2010; 43:634-44. [PMID: 20499015 DOI: 10.1590/s0100-879x2010007500046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2009] [Accepted: 04/30/2010] [Indexed: 11/22/2022] Open
Abstract
The effectiveness of the caspase-9-based artificial "death switch" as a safety measure for gene therapy based on the erythropoietin (Epo) hormone was tested in vitro and in vivo using the chemical inducer of dimerization, AP20187. Plasmids encoding the dimeric murine Epo, the tetracycline-controlled transactivator and inducible caspase 9 (ptet-mEpoD, ptet-tTAk and pSH1/Sn-E-Fv'-Fvls-casp9-E, respectively) were used in this study. AP20187 induced apoptosis of iCasp9-modified C2C12 myoblasts. In vivo, two groups of male C57BI/6 mice, 8-12 weeks old, were injected intramuscularly with 5 microg/50 g ptet-mEpoD and 0.5 microg/50 g ptet-tTAk. There were 20 animals in group 1 and 36 animals in group 2. Animals from group 2 were also injected with the 6 microg/50 g iCasp9 plasmid. Seventy percent of the animals showed an increase in hematocrit of more than 65% for more than 15 weeks. AP20187 administration significantly reduced hematocrit and plasma Epo levels in 30% of the animals belonging to group 2. TUNEL-positive cells were detected in the muscle of at least 50% of the animals treated with AP20187. Doxycycline administration was efficient in controlling Epo secretion in both groups. We conclude that inducible caspase 9 did not interfere with gene transfer, gene expression or tetracycline control and may be used as a safety mechanism for gene therapy. However, more studies are necessary to improve the efficacy of this technique, for example, the use of lentivirus vector.
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Affiliation(s)
- D S Souza
- Centro de Hematologia e Hemoterapia, Departamento de Clínica Médica, Universidade de Campinas, Campinas, SP, Brasil
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Scott GB, de Wynter EA, Cook GP. Detecting variable (V), diversity (D) and joining (J) gene segment recombination using a two-colour fluorescence system. Mob DNA 2010; 1:9. [PMID: 20226006 PMCID: PMC3225881 DOI: 10.1186/1759-8753-1-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Accepted: 03/01/2010] [Indexed: 11/12/2022] Open
Abstract
Background Diversity of immunoglobulins and the T cell antigen receptors is achieved via the recombination activating gene (RAG)-mediated rearrangement of variable (V), diversity (D) and joining (J) gene segments, and this underpins the efficient recognition of a seemingly limitless array of antigens. Analysis of V(D)J recombination activity is typically performed using extrachromosomal recombination substrates that are recovered from transfected cells and selected using bacterial transformation. We have developed a two-colour fluorescence-based system that simplifies detection of both deletion and inversion joining events mediated by RAG proteins. Results This system employs two fluorescent reporter genes that differentially mark unrearranged substrates and those that have undergone RAG-mediated deletion or inversion events. The recombination products bear the hallmarks of true V(D)J recombination and activity can be detected using fluorescence microscopy or flow cytometry. Recombination events can be detected without the need for cytotoxic selection of recombination products and the system allows analysis of recombination activity using substrates integrated into the genome. Conclusions This system will be useful in the analysis and exploitation of the V(D)J recombination machinery and suggests that similar approaches could be used to replace expression of one gene with another during lymphocyte development.
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Affiliation(s)
- Gina B Scott
- Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK.
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Ito S, Ozawa S, Ikoma T, Yajima N, Kiyono T, Hata RI. Expression of a chemokine BRAK/CXCL14 in oral floor carcinoma cells reduces the settlement rate of the cells and suppresses their proliferation in vivo. Biomed Res 2010; 31:199-206. [DOI: 10.2220/biomedres.31.199] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Ogura E, Okuda Y, Kondoh H, Kamachi Y. Adaptation of GAL4 activators for GAL4 enhancer trapping in zebrafish. Dev Dyn 2009; 238:641-55. [PMID: 19191223 DOI: 10.1002/dvdy.21863] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
An enhancer trap-based GAL4-UAS system in zebrafish requires strong GAL4 activators with minimal adverse effects. However, the activity of yeast GAL4 is too low in zebrafish, while a fusion protein of the GAL4 DNA-binding domain and the VP16 activation domain is toxic to embryonic development, even when expressed at low levels. To alleviate this toxicity, we developed variant GAL4 activators by fusing either multimeric forms of the VP16 minimal activation domain or the NF-kappaB activation domain to the GAL4 DNA-binding domain. These variant GAL4 activators are sufficiently innocuous and yet highly effective transactivators in developing zebrafish. Enhancer-trap vectors containing these GAL4 activators downstream of an appropriate weak promoter were randomly inserted into the zebrafish genome using the Sleeping Beauty transposon system. By the combination of these genetic elements, we have successfully developed enhancer trap lines that activate UAS-dependent reporter genes in a tissue-specific fashion that reflects trapped enhancer activities.
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Affiliation(s)
- Eri Ogura
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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Stewart HJ, Leroux-Carlucci MA, Sion CJM, Mitrophanous KA, Radcliffe PA. Development of inducible EIAV-based lentiviral vector packaging and producer cell lines. Gene Ther 2009; 16:805-14. [DOI: 10.1038/gt.2009.20] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Tomioka Y, Miyazaki T, Taharaguchi S, Yoshino S, Morimatsu M, Uede T, Ono E, Watanabe M. Cerebellar pathology in transgenic mice expressing the pseudorabies virus immediate-early protein IE180. Eur J Neurosci 2008; 27:2115-32. [PMID: 18412631 DOI: 10.1111/j.1460-9568.2008.06174.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pseudorabies virus is an alphaherpesvirus causing fatal neurological diseases in animals. Pseudorabies virus carries a gene encoding immediate-early (IE) protein IE180, which controls the transcription of other viral and host cell genes. Previously, we reported that transgenic expression of IE180 in mice causes severe ataxia and cerebellar deformity. Here we identified profound abnormalities in adult IE180 transgenic mice, including malpositioning of Purkinje cells (PCs), granule cells (GCs) and Bergmann glia (BG), impaired dendritogenesis and synaptogenesis in PCs, disoriented BG fibers, absence of molecular layer interneurons, and increased apoptosis of neurons and glia. In accordance with the cellular defects, we found the expression of IE180 in PCs, GCs and astrocytes during cerebellar development. We next examined transgenic mice expressing truncated IE180 mutants: dlN132 lacking the acidic transcriptional active domain, dlC629 lacking the nuclear localization signal and dlC1081 having all known domains but lacking the carboxyl-terminal sequence. Despite similar expression levels of the transgenes, ataxia and cerebellar defects were only manifested in the dlC1081 transgenic mice but their phenotypes were milder compared with the IE180 transgenic mice. In the dlC1081 transgenic mice, cerebellar neurons and glia were normally positioned but cerebellar size was severely reduced due to GC deficits. Interestingly, dlC1081 was mainly expressed in the GCs with low expression in a few BG. Taken together, the present findings clarified a causal relationship between cerebellar pathology and cellular expression of IE180, and further afforded an experimental insight into different symptomatic severity as a consequence of different cellular defects caused by such cytotoxic viral agents.
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Affiliation(s)
- Yukiko Tomioka
- Laboratory of Animal Experiment for Disease Model, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
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Lo HL, Yee JK. Production of vesicular stomatitis virus G glycoprotein (VSV-G) pseudotyped retroviral vectors. ACTA ACUST UNITED AC 2008; Chapter 12:Unit 12.7. [PMID: 18428407 DOI: 10.1002/0471142905.hg1207s52] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Retrovirus pseudotype is defined as the genome of one retrovirus encapsidated by the envelope protein of a second virus. The host range of the pseudotype is that of the virus donating the envelope protein. Two procedures that use 293GP cells, which are derived from human kidney 293 cells, are described here. The first is based on the high transient transfection efficiency of 293 cells. The retroviral construct and an expression plasmid for VSV-G are co-transfected into 293GP cells that stably express MLV gag and pol proteins. Transiently generated virus is then harvested during consecutive days following DNA transfection. The second procedure involves stable 293GP cell lines containing the VSV-G gene under the control of a promoter whose activity is regulated by tetracycline. Cell lines containing the retroviral vector of interest are established under noninduced conditions. Infectious virus can be harvested following the induction of VSV-G expression in these cell lines.
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Affiliation(s)
- Hsin-Lung Lo
- City of Hope National Medical Center, Duarte, California, USA
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37
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Chen SC, Henry DO, Reczek PR, Wong MK. Plasminogen activator inhibitor-1 inhibits prostate tumor growth through endothelial apoptosis. Mol Cancer Ther 2008; 7:1227-36. [DOI: 10.1158/1535-7163.mct-08-0051] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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38
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Sabatakos G, Rowe GC, Kveiborg M, Wu M, Neff L, Chiusaroli R, Philbrick WM, Baron R. Doubly truncated FosB isoform (Delta2DeltaFosB) induces osteosclerosis in transgenic mice and modulates expression and phosphorylation of Smads in osteoblasts independent of intrinsic AP-1 activity. J Bone Miner Res 2008; 23:584-95. [PMID: 18433296 PMCID: PMC2674536 DOI: 10.1359/jbmr.080110] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 12/14/2007] [Accepted: 01/28/2008] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Activator protein (AP)-1 family members play important roles in the development and maintenance of the adult skeleton. Transgenic mice that overexpress the naturally occurring DeltaFosB splice variant of FosB develop severe osteosclerosis. Translation of Deltafosb mRNA produces both DeltaFosB and a further truncated isoform (Delta2DeltaFosB) that lacks known transactivation domains but, like DeltaFosB, induces increased expression of osteoblast marker genes. MATERIALS AND METHODS To test Delta2DeltaFosB's ability to induce bone formation in vivo, we generated transgenic mice that overexpress only Delta2DeltaFosB using the enolase 2 (ENO2) promoter-driven bitransgenic Tet-Off system. RESULTS Despite Delta2DeltaFosB's failure to induce transcription of an AP-1 reporter gene, the transgenic mice exhibited both the bone and the fat phenotypes seen in the ENO2-DeltaFosB mice. Both DeltaFosB and Delta2DeltaFosB activated the BMP-responsive Xvent-luc reporter gene and increased Smad1 expression. Delta2DeltaFosB enhanced BMP-induced Smad1 phosphorylation and the translocation of phospho-Smad1 (pSmad1) to the nucleus more efficiently than DeltaFosB and showed a reduced induction of inhibitory Smad6 expression. CONCLUSIONS DeltaFosB's AP-1 transactivating function is not needed to induce increased bone formation, and Delta2DeltaFosB may act, at least in part, by increasing Smad1 expression, phosphorylation, and translocation to the nucleus.
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Affiliation(s)
- George Sabatakos
- These authors contributed equally to this manuscript
- Department of Orthopaedics, Yale University School of Medicine, New Haven, Connecticut, USA
- Present address: Procter & Gamble Pharmaceuticals, New Technology Development, Mason, Ohio, USA
| | - Glenn C Rowe
- These authors contributed equally to this manuscript
- Department of Orthopaedics, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Oral Medicine, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Marie Kveiborg
- These authors contributed equally to this manuscript
- Department of Orthopaedics, Yale University School of Medicine, New Haven, Connecticut, USA
- Present address: Department of Biomedical Sciences and Biotech Research & Innovation Center, University of Copenhagen, Copenhagen, Denmark
| | - Meilin Wu
- Department of Orthopaedics, Yale University School of Medicine, New Haven, Connecticut, USA
- Cardiovascular Division, Molecular Cardiology Research Center, University of Pennsylvania Medical School, Philadelphia, Pennsylvania, USA:
| | - Lynn Neff
- Department of Orthopaedics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Riccardo Chiusaroli
- Department of Orthopaedics, Yale University School of Medicine, New Haven, Connecticut, USA
- Present address: Rotta Pharmaceuticals, Milan, Italy
| | - William M Philbrick
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Roland Baron
- Department of Orthopaedics, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Oral Medicine, Harvard School of Dental Medicine, Boston, Massachusetts, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, USA
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Pettway GJ, Meganck JA, Koh AJ, Keller ET, Goldstein SA, McCauley LK. Parathyroid hormone mediates bone growth through the regulation of osteoblast proliferation and differentiation. Bone 2008; 42:806-18. [PMID: 18234576 PMCID: PMC2677418 DOI: 10.1016/j.bone.2007.11.017] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 11/19/2007] [Accepted: 11/26/2007] [Indexed: 02/07/2023]
Abstract
PTH (1-34) is the only FDA-approved anabolic agent for osteoporosis treatment in the U.S., but its mechanisms are not completely understood. This study investigated PTH effects on osteogenic cells at various stages of differentiation and proliferation using an engineered bone growth model in vivo. Ossicles were generated from bone marrow stromal cells (BMSCs) implanted in immunocompromised mice. Three weeks of PTH (40 microg/kg/day) or vehicle treatment initiated 1 day, 1, 2, or 3 weeks after BMSC implantation resulted in an anabolic response in PTH-treated implants (via histomorphometry and muCT) in all treatment groups. A novel in vivo tracking strategy with luciferase tagged BMSCs and weekly bioluminescent imaging of ossicles revealed increased donor cell proliferation in PTH-treated ossicles. The greatest increase occurred during the first week, and the activity remained elevated in PTH-treated implants over time. Zoledronic acid (ZA) was combined with PTH to delineate interactive mechanisms of these bone active agents. Combining ZA with PTH treatment reduced the PTH-mediated increase in luciferase BMSC activity, serum osteocalcin, and serum tartrate resistant acid phosphotase-5b (TRAP-5b) but ZA did not reduce the PTH-induced increase in total bone. Since zoledronic acid reduced PTH-induced proliferation without reducing bone volume, these data suggest that combining PTH and bisphosphonate therapy warrants further investigation in the treatment of bone disorders.
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Affiliation(s)
- Glenda J. Pettway
- Department of Biomedical Engineering, University of Michigan College of Engineering
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry
| | - Jeffrey A. Meganck
- Department of Biomedical Engineering, University of Michigan College of Engineering
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, University of Michigan
| | - Amy J. Koh
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry
| | - Evan T. Keller
- Department of Urology, University of Michigan School of Medicine
- Department of Pathology, University of Michigan School of Medicine
| | - Steven A. Goldstein
- Department of Biomedical Engineering, University of Michigan College of Engineering
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, University of Michigan
| | - Laurie K. McCauley
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry
- Department of Pathology, University of Michigan School of Medicine
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Shockett P, Schatz D. Inducible gene expression using an autoregulatory, tetracycline-controlled system. ACTA ACUST UNITED AC 2008; Chapter 16:Unit 16.14. [PMID: 18265300 DOI: 10.1002/0471142727.mb1614s60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The protocols in this unit describe the transfection of adherent cells and the testing of resultant clones for inducible transactivator or target gene protein expression. Stably transfected fibroblast cell lines expressing transactivator and target gene(s) can be derived by first cotransfecting pTet-tTAk and a plasmid encoding a selectable marker and obtaining stable lines with inducible transactivator expression. These lines are subsequently stably cotransfected with plasmids encoding the target gene(s) and a second selectable marker. The procedure may also be used to cotransfect pTet-tTAk with the target gene-encoding plasmid(s) and a single selectable marker plasmid. A support protocol describes methods to test stably transfected cell lines for inducible gene expression, for transient transfection and induction of tet-regulated plasmids, and for detection of the tTAk gene in cells (or transgenic mice).
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Affiliation(s)
- Penny Shockett
- Yale University School of Medicine, New Haven, Connecticut, USA
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41
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Gulick J, Robbins J. Regulation of transgene expression using tetracycline. ACTA ACUST UNITED AC 2008; Chapter 23:Unit 23.12. [PMID: 18265363 DOI: 10.1002/0471142727.mb2312s71] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transgenesis has proven useful in creating animal models that mimic certain disease states, providing a mechanistic approach for understanding the underlying disease mechanisms at the molecular and cellular levels. With traditional transgenics, the gene of interest is cloned behind a promoter that has the desired expression pattern, allowing the gene to be expressed in those tissues at the developmental times that the promoter is active. In order to more precisely control gene expression both in vitro and in vivo, inducible systems that use pharmacologic intervention to control transgene expression have been developed (UNIT 16.14). As previously described, the system consists of two components, an activator that is regulated by tetracycline and a responder that is dependent upon the activator. Both limbs of the system will be discussed in the context of inducible and reversible transgene expression that is cell type- or organ-specific, with particular attention paid to the cardiovascular system.
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Affiliation(s)
- James Gulick
- Cincinnati Children's Hospital, University of Cincinnati, Cincinnati, Ohio, USA
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42
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Shockett P, Schatz D. Inducible gene expression using an autoregulatory, tetracycline-controlled system. CURRENT PROTOCOLS IN CELL BIOLOGY 2008; Chapter 20:20.8.1-20.8.10. [PMID: 18228465 DOI: 10.1002/0471143030.cb2008s27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The protocols in this unit describe the transfection of adherent cells and the testing of resultant clones for inducible transactivator or target gene protein expression. Stably transfected fibroblast cell lines expressing transactivator and target gene(s) can be derived by first cotransfecting pTet-tTAk and a plasmid encoding a selectable marker and obtaining stable lines with inducible transactivator expression. These lines are subsequently stably cotransfected with plasmids encoding the target gene(s) and a second selectable marker. The procedure may also be used to cotransfect pTet-tTAk with the target gene-encoding plasmid(s) and a single selectable marker plasmid. A support protocol describes methods to test stably transfected cell lines for inducible gene expression, for transient transfection and induction of tet-regulated plasmids, and for detection of the tTAk gene in cells (or transgenic mice).
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Affiliation(s)
| | - David Schatz
- Howard Hughes Medical Institute and Yale University School of Medicine, New Haven, Connecticut
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43
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Intrathecal coelectrotransfer of a tetracycline-inducible, three-plasmid-based system to achieve tightly regulated antinociceptive gene therapy for mononeuropathic rats. J Gene Med 2008; 10:208-16. [DOI: 10.1002/jgm.1132] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Tenbaum SP, Papaioannou M, Reeb CA, Goeman F, Escher N, Kob R, von Eggeling F, Melle C, Baniahmad A. Alien inhibits E2F1 gene expression and cell proliferation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1773:1447-54. [PMID: 17570542 DOI: 10.1016/j.bbamcr.2007.04.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 04/25/2007] [Accepted: 04/28/2007] [Indexed: 12/24/2022]
Abstract
Recently, using a proteomic approach we have identified the corepressor Alien as a novel interacting factor of the cell cycle regulator E2F1. Unclear was whether this interaction influences cell proliferation and endogenous E2F1 target gene expression. Here, we show by chromatin immunoprecipitation (ChIP) that Alien is recruited in vivo to the E2F binding sites present in the E2F1 gene promoter, inhibits the transactivation of E2F1 and represses endogenous E2F1 gene expression. Interestingly, using synchronized cells to assess the expression of Alien profile during cell cycle the levels of endogenous Alien are increased during G1, G1/S and G2 phase. Furthermore, stable transfection of Alien leads to reduction of cell proliferation. Thus, the data suggest that Alien acts as a corepressor for E2F1 and is involved in cell cycle regulation.
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Affiliation(s)
- Stephan P Tenbaum
- Molecular Genetics, Institute of Human Genetics and Anthropology, Friedrich-Schiller-University, 07740 Jena, Germany
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Stringent and reproducible tetracycline-regulated transgene expression by site-specific insertion at chromosomal loci with pre-characterised induction characteristics. BMC Mol Biol 2007; 8:30. [PMID: 17493262 PMCID: PMC1884169 DOI: 10.1186/1471-2199-8-30] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Accepted: 05/10/2007] [Indexed: 12/16/2022] Open
Abstract
Background The ability to regulate transgene expression has many applications, mostly concerning the analysis of gene function. Desirable induction characteristics, such as low un-induced expression, high induced expression and limited cellular heterogeneity, can be seriously impaired by chromosomal position effects at the site of transgene integration. Many clones may therefore need to be screened before one with optimal induction characteristics is identified. Furthermore, such screens must be repeated for each new transgene investigated, and comparisons between clones with different transgenes is complicated by their different integration sites. Results To circumvent these problems we have developed a "screen and insert" strategy in which clones carrying a transgene for a fluorescent reporter are first screened for those with optimal induction characteristics. Site-specific recombination (SSR) is then be used repeatedly to insert any new transgene at the reporter transgene locus of such clones so that optimal induction characteristics are conferred upon it. Here we have tested in a human fibrosarcoma cell line (HT1080) two of many possible implementations of this approach. Clones (e.g. Rht14-10) in which a GFP reporter gene is very stringently regulated by the tetracycline (tet) transactivator (tTA) protein were first identified flow-cytometrically. Transgenes encoding luciferase, I-SceI endonuclease or Rad52 were then inserted by SSR at a LoxP site adjacent to the GFP gene resulting stringent tet-regulated transgene expression. In clone Rht14-10, increases in expression from essentially background levels (+tet) to more than 104-fold above background (-tet) were reproducibly detected after Cre-mediated insertion of either the luciferase or the I-SceI transgenes. Conclusion Although previous methods have made use of SSR to integrate transgenes at defined sites, none has effectively combined this with a pre-selection step to identify integration sites that support optimal regulatory characteristics. Rht14-10 and similar HT1080-derived clones can now be used in conjunction with a convenient delivery vector (pIN2-neoMCS), in a simple 3-step protocol leading to stringent and reproducible transgene regulation. This approach will be particularly useful for transgenes whose products are very active at low concentrations and/or for comparisons of multiple related transgenes.
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46
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Yao F, Pomahac B, Visovatti S, Chen M, Johnson S, Augustinova H, Svensjo T, Eriksson E. Systemic and Localized Reversible Regulation of Transgene Expression by Tetracycline with tetR-Mediated Transcription Repression Switch. J Surg Res 2007; 138:267-74. [PMID: 17254606 DOI: 10.1016/j.jss.2006.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 04/26/2006] [Accepted: 05/01/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND We recently developed a new tetracycline-inducible gene switch employing the tetracycline operator-containing hCMV major immediate-early promoter and the tetracycline repressor, tetR, rather than the previously used tetR-mammalian cell transcription factor fusion derivatives. MATERIALS AND METHODS The present study demonstrates that this tetR-mediated transcription repression system can function as a powerful gene switch for On-and-Off regulation of therapeutic gene expression in ex vivo gene transfer protocols. Firstly, for achieving regulated gene expression in a localized tissue environment, R11/OEGF cells, a stable line that expresses hEGF under the control of the tetR-mediated transcription repression switch, were transplanted into porcine full-thickness wounds enclosed by wound chambers. RESULTS By topically applying tetracycline in wound chambers at various concentrations or at different time points post-transplantation, the levels and timing of hEGF expression in transplanted wounds could be reversibly regulated by tetracycline. Over 3000-fold induction in hEGF expression was achieved in the local wound microenvironment. Secondly, R11/OEGF cells were intramuscularly injected into NCr outbread nude mice to test the efficacy of intermittent systemic gene delivery of a soluble peptide(s). CONCLUSIONS Basal circulating hEGF was undetectable and induced up to at least 1,500-fold after administration of tetracycline. Furthermore, the timing and duration of hEGF expression could be finely adjusted by the presence or the absence of tetracycline in the drinking water.
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Affiliation(s)
- Feng Yao
- Laboratory of Tissue Repair and Gene Transfer, Plastic Surgery, Brigham and Women's Hospital, and Department of Surgery, Harvard Medical School, Boston, Massachusetts 02115, USA.
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47
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Welman A, Barraclough J, Dive C. Tetracycline regulated systems in functional oncogenomics. TRANSLATIONAL ONCOGENOMICS 2007; 2:17-33. [PMID: 23645981 PMCID: PMC3634622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The increasing number of proteomic and DNA-microarray studies is continually providing a steady acquisition of data on the molecular abnormalities associated with human tumors. Rapid translation of this accumulating biological information into better diagnostics and more effective cancer therapeutics in the clinic depends on the use of robust function-testing strategies. Such strategies should allow identification of molecular lesions that are essential for the maintenance of the transformed phenotype and enable validation of potential drug-targets. The tetracycline regulated gene expression/ suppression systems (Tet-systems) developed and optimized by bioengineers over recent years seem to be very well suited for the function-testing purposes in cancer research. We review the history and latest improvements in Tet-technology in the context of functional oncogenomics.
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Affiliation(s)
- Arkadiusz Welman
- Cancer Research U.K., Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, United Kingdom.,Correspondence: Arkadiusz Welman, Ph.D, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, United Kingdom. Tel: +44 161 446 8104; Fax: +44 161 446 3109;
| | - Jane Barraclough
- Cancer Research U.K., Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, United Kingdom
| | - Caroline Dive
- Cancer Research U.K., Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, United Kingdom
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Judelson HS, Narayan R, Fong AMVA, Tani S, Kim KS. Performance of a tetracycline-responsive transactivator system for regulating transgenes in the oomycete Phytophthora infestans. Curr Genet 2007; 51:297-307. [PMID: 17377792 DOI: 10.1007/s00294-007-0125-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Revised: 02/23/2007] [Accepted: 02/24/2007] [Indexed: 11/27/2022]
Abstract
The oomycete genus Phytophthora includes many important plant pathogens for which extensive genome data exist, but lacking is an inducible expression system to study contributions of their genes to growth and pathogenicity. Here the adaptation of the reverse tetracycline transactivator (rtTA) system to P. infestans is described. Vectors were developed containing rtTA expressed from an oomycete promoter, and beta-glucuronidase (GUS) controlled by TetR binding sites fused to a minimal oomycete promoter. Transformants were obtained in which GUS was expressed in a dose-dependent manner by the rtTA inducer doxycycline, indicating that the gene switch functions in P. infestans. However, toxicity of rtTA hindered the isolation of transformants if expressed on the same plasmid as the nptII selection marker. Better results were obtained by cotransforming those genes on separate plasmids, with 92% of transformants acquiring both DNAs although only 4% expressed rtTA at detectable levels. Low levels of reporter activity were measured in such transformants, suggesting that rtTA activated transcription weakly. Also, significant variation in the sensitivity of isolates to doxycycline and tetracycline was observed. These results are useful both in terms of developing tools for functional genomics and understanding the fate of DNA during Phytophthora transformation.
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Affiliation(s)
- Howard S Judelson
- Department of Plant Pathology, University of California, Riverside, CA 92521, USA.
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49
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Klokk TI, Kurys P, Elbi C, Nagaich AK, Hendarwanto A, Slagsvold T, Chang CY, Hager GL, Saatcioglu F. Ligand-specific dynamics of the androgen receptor at its response element in living cells. Mol Cell Biol 2007; 27:1823-43. [PMID: 17189428 PMCID: PMC1820481 DOI: 10.1128/mcb.01297-06] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 08/24/2006] [Accepted: 12/08/2006] [Indexed: 12/29/2022] Open
Abstract
Androgens have key roles in normal physiology and in male sexual differentiation as well as in pathological conditions such as prostate cancer. Androgens act through the androgen receptor (AR), which is a ligand-modulated transcription factor. Antiandrogens block AR function and are widely used in disease states, but little is known about their mechanism of action in vivo. Here, we describe a rapid differential interaction of AR with target genomic sites in living cells in the presence of agonists which coincides with the recruitment of BRM ATPase complex and chromatin remodeling, resulting in transcriptional activation. In contrast, the interaction of antagonist-bound or mutant AR with its target was found to be kinetically different: it was dramatically faster, occurred without chromatin remodeling, and resulted in the lack of transcriptional inhibition. Fluorescent resonance energy transfer analysis of wild-type AR and a transcriptionally compromised mutant at the hormone response element showed that intramolecular interactions between the N and C termini of AR play a key functional role in vivo compared to intermolecular interactions between two neighboring ARs. These data provide a kinetic and mechanistic basis for regulation of gene expression by androgens and antiandrogens in living cells.
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MESH Headings
- Adenocarcinoma/pathology
- Androgen Antagonists/pharmacology
- Androgens/pharmacology
- Anilides/pharmacology
- Animals
- Cell Line, Tumor
- Chromatin Assembly and Disassembly
- Cyproterone Acetate/pharmacology
- Dihydrotestosterone/pharmacology
- Female
- Fluorescence Recovery After Photobleaching
- Flutamide/analogs & derivatives
- Flutamide/pharmacology
- Genes, Reporter
- Green Fluorescent Proteins/metabolism
- In Situ Hybridization, Fluorescence
- Ligands
- Luciferases/metabolism
- Mammary Neoplasms, Animal/pathology
- Mammary Tumor Virus, Mouse/genetics
- Metribolone/pharmacology
- Mice
- Microscopy, Video
- Mifepristone/pharmacology
- Models, Biological
- Nitriles/pharmacology
- Plasmids
- Promoter Regions, Genetic
- Receptors, Androgen/drug effects
- Receptors, Androgen/metabolism
- Response Elements/physiology
- Testosterone/pharmacology
- Tosyl Compounds/pharmacology
- Transcription, Genetic
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Affiliation(s)
- Tove I Klokk
- Department of Molecular Biosciences, University of Oslo, Postboks 1041 Blindern, 0316 Oslo, Norway
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50
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Ziv I, Fuchs Y, Preger E, Shabtay A, Harduf H, Zilpa T, Dym N, Ron D. The human sef-a isoform utilizes different mechanisms to regulate receptor tyrosine kinase signaling pathways and subsequent cell fate. J Biol Chem 2006; 281:39225-35. [PMID: 17035228 DOI: 10.1074/jbc.m607327200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Negative feedback is among the key mechanisms for regulating receptor tyrosine kinase (RTK) signaling. Human Sef, a recently identified inhibitor of RTK signaling, encodes different isoforms, including a membrane spanning (hSef-a) and a cytosolic (hSef-b) isoform. Previously, we reported that hSef-b inhibited fibroblast proliferation and prevented the activation of mitogen-activated protein kinase (MAPK), without affecting protein kinase B/Akt or p38 MAPK. Conflicting results were reported concerning hSef-a inhibition of MAPK activation, and the effect of hSef-a on other RTK-induced signaling pathways is unknown. Here we show that, in fibroblasts, similar to hSef-b, ectopic expression of hSef-a inhibited fibroblast growth factor-induced cell proliferation. Unlike hSef-b, however, the growth arrest was mediated via a MAPK-independent mechanism, and was accompanied by elevated p38 MAPK phosphorylation and inhibition of protein kinase B/Akt. In addition, hSef-a, but not hSef-b, mediated apoptosis in fibroblast growth factor-stimulated cells. Chemical inhibitor of p38 MAPK abrogated the effect of hSef-a on apoptosis. In epithelial cells, ectopic expression of hSef-a inhibited the activation of MAPK, whereas down-regulation of endogenous hSef-a significantly increased MAPK activation and accelerated growth factor-dependent cell proliferation. These results indicate that hSef-a is a multifunctional negative modulator of RTK signaling and clearly demonstrate that hSef-a can inhibit the activation of MAPK, although in a cell type-specific manner. Moreover, the differences between the activities of hSef-a and hSef-b suggest that hSef isoforms can control signal specificity and subsequent cell fate by utilizing different mechanisms to modulate RTK signaling.
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Affiliation(s)
- Inbal Ziv
- Department of Biology, Technion Institute of Technology, Haifa 32000, Israel
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