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Doszyn O, Dulski T, Zmorzynska J. Diving into the zebrafish brain: exploring neuroscience frontiers with genetic tools, imaging techniques, and behavioral insights. Front Mol Neurosci 2024; 17:1358844. [PMID: 38533456 PMCID: PMC10963419 DOI: 10.3389/fnmol.2024.1358844] [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: 12/21/2023] [Accepted: 02/27/2024] [Indexed: 03/28/2024] Open
Abstract
The zebrafish (Danio rerio) is increasingly used in neuroscience research. Zebrafish are relatively easy to maintain, and their high fecundity makes them suitable for high-throughput experiments. Their small, transparent embryos and larvae allow for easy microscopic imaging of the developing brain. Zebrafish also share a high degree of genetic similarity with humans, and are amenable to genetic manipulation techniques, such as gene knockdown, knockout, or knock-in, which allows researchers to study the role of specific genes relevant to human brain development, function, and disease. Zebrafish can also serve as a model for behavioral studies, including locomotion, learning, and social interactions. In this review, we present state-of-the-art methods to study the brain function in zebrafish, including genetic tools for labeling single neurons and neuronal circuits, live imaging of neural activity, synaptic dynamics and protein interactions in the zebrafish brain, optogenetic manipulation, and the use of virtual reality technology for behavioral testing. We highlight the potential of zebrafish for neuroscience research, especially regarding brain development, neuronal circuits, and genetic-based disorders and discuss its certain limitations as a model.
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Affiliation(s)
| | | | - J. Zmorzynska
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology in Warsaw (IIMCB), Warsaw, Poland
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2
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Sparrelid E, Olthof PB, Dasari BVM, Erdmann JI, Santol J, Starlinger P, Gilg S. Current evidence on posthepatectomy liver failure: comprehensive review. BJS Open 2022; 6:6840812. [PMID: 36415029 PMCID: PMC9681670 DOI: 10.1093/bjsopen/zrac142] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/21/2022] [Accepted: 10/03/2022] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION Despite important advances in many areas of hepatobiliary surgical practice during the past decades, posthepatectomy liver failure (PHLF) still represents an important clinical challenge for the hepatobiliary surgeon. The aim of this review is to present the current body of evidence regarding different aspects of PHLF. METHODS A literature review was conducted to identify relevant articles for each topic of PHLF covered in this review. The literature search was performed using Medical Subject Heading terms on PubMed for articles on PHLF in English until May 2022. RESULTS Uniform reporting on PHLF is lacking due to the use of various definitions in the literature. There is no consensus on optimal preoperative assessment before major hepatectomy to avoid PHLF, although many try to estimate future liver remnant function. Once PHLF occurs, there is still no effective treatment, except liver transplantation, where the reported experience is limited. DISCUSSION Strict adherence to one definition is advised when reporting data on PHLF. The use of the International Study Group of Liver Surgery criteria of PHLF is recommended. There is still no widespread established method for future liver remnant function assessment. Liver transplantation is currently the only effective way to treat severe, intractable PHLF, but for many indications, this treatment is not available in most countries.
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Affiliation(s)
- Ernesto Sparrelid
- Department of Clinical Science, Intervention and Technology, Division of Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Pim B Olthof
- Department of Surgery, Erasmus MC, Rotterdam, The Netherlands.,Department of Surgery, Amsterdam UMC, Amsterdam, The Netherlands
| | - Bobby V M Dasari
- Department of HPB Surgery and Liver Transplantation, Queen Elizabeth Hospital, Birmingham, UK.,University of Birmingham, Birmingham, UK
| | - Joris I Erdmann
- Department of Surgery, Amsterdam UMC, Amsterdam, The Netherlands
| | - Jonas Santol
- Department of Surgery, HPB Center, Viennese Health Network, Clinic Favoriten and Sigmund Freud Private University, Vienna, Austria.,Department of Vascular Biology and Thrombosis Research, Centre of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Patrick Starlinger
- Division of General Surgery, Department of Surgery, Medical University of Vienna, General Hospital of Vienna, Vienna, Austria.,Department of Surgery, Division of Hepatobiliary and Pancreas Surgery, Mayo Clinic, Rochester, New York, USA
| | - Stefan Gilg
- Department of Clinical Science, Intervention and Technology, Division of Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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3
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Ineichen BV, Di Palma S, Laczko E, Liddelow SA, Neumann S, Schwab ME, Mosberger AC. Regional Differences in Penetration of the Protein Stabilizer Trimethoprim (TMP) in the Rat Central Nervous System. Front Mol Neurosci 2020; 13:167. [PMID: 33013318 PMCID: PMC7496896 DOI: 10.3389/fnmol.2020.00167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/11/2020] [Indexed: 12/04/2022] Open
Abstract
Regulating gene expression at the protein level is becoming increasingly important for answering basic questions in neurobiology. Several techniques using destabilizing domains (DD) on transgenes, which can be activated or deactivated by specific drugs, have been developed to achieve this goal. A DD from bacterial dihydrofolate reductase bound and stabilized by trimethoprim (TMP) represents such a tool. To control transgenic protein levels in the brain, the DD-regulating drugs need to have sufficient penetration into the central nervous system (CNS). Yet, very limited information is available on TMP pharmacokinetics in the CNS following systemic injection. Here, we performed a pharmacokinetic study on the penetration of TMP into different CNS compartments in the rat. We used mass spectrometry to measure TMP concentrations in serum, cerebrospinal fluid (CSF) and tissue samples of different CNS regions upon intraperitoneal TMP injection. We show that TMP quickly (within 10 min) penetrates from serum to CSF through the blood-CSF barrier. TMP also shows quick penetration into brain tissue but concentrations were an order of magnitude lower compared to serum or CSF. TMP concentration in spinal cord was lower than in any other analyzed CNS area. Nevertheless, effective levels of TMP to stabilize DDs can be reached in the CNS with half-lives around 2 h. These data show that TMP has good and fast penetration properties into the CNS and is therefore a valuable ligand for precisely controlling protein expression in the CNS in rodents.
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Affiliation(s)
- Benjamin V Ineichen
- Department of Health Sciences and Technology, Brain Research Institute, University of Zurich, ETH Zürich, Zurich, Switzerland
| | - Serena Di Palma
- Functional Genomics Center Zurich, University of Zurich, ETH Zürich, Zurich, Switzerland
| | - Endre Laczko
- Functional Genomics Center Zurich, University of Zurich, ETH Zürich, Zurich, Switzerland
| | - Shane A Liddelow
- Neuroscience Institute, NYU School of Medicine, New York, NY, United States.,Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY, United States.,Department of Ophthalmology, NYU School of Medicine, New York, NY, United States
| | - Susanne Neumann
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Martin E Schwab
- Department of Health Sciences and Technology, Brain Research Institute, University of Zurich, ETH Zürich, Zurich, Switzerland
| | - Alice C Mosberger
- Department of Health Sciences and Technology, Brain Research Institute, University of Zurich, ETH Zürich, Zurich, Switzerland
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4
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Testing the Cre-mediated genetic switch for the generation of conditional knock-in mice. PLoS One 2019; 14:e0213660. [PMID: 30865697 PMCID: PMC6415906 DOI: 10.1371/journal.pone.0213660] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 02/25/2019] [Indexed: 12/20/2022] Open
Abstract
The Cre-mediated genetic switch combines the ability of Cre recombinase to stably invert or excise a DNA fragment depending upon the orientation of flanking mutant loxP sites. In this work, we have tested this strategy in vivo with the aim to generate two conditional knock-in mice for missense mutations in the Impad1 and Clcn7 genes causing two different skeletal dysplasias. Targeting constructs were generated in which the Impad1 exon 2 and an inverted exon 2* and the Clcn7 exon 7 and an inverted exon 7* containing the point mutations were flanked by mutant loxP sites in a head-to-head orientation. When the Cre recombinase is present, the DNA flanked by the mutant loxP sites is expected to be stably inverted leading to the activation of the mutated exon. The targeting vectors were used to generate heterozygous floxed mice in which inversion of the wild-type with the mutant exon has not occurred yet. To generate knock-in mice, floxed animals were mated to a global Cre-deleter mouse strain for stable inversion and activation of the mutation. Unexpectedly the phenotype of homozygous Impad1 knock-in animals overlaps with the lethal phenotype described previously in Impad1 knock-out mice. Similarly, the phenotype of homozygous Clcn7 floxed mice overlaps with Clcn7 knock-out mice. Expression studies by qPCR and RT-PCR demonstrated that mutant mRNA underwent abnormal splicing leading to the synthesis of non-functional proteins. Thus, the skeletal phenotypes in both murine strains were not caused by the missense mutations, but by aberrant splicing. Our data demonstrate that the Cre mediated genetic switch strategy should be considered cautiously for the generation of conditional knock-in mice.
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5
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Gurumurthy CB, Lloyd KCK. Generating mouse models for biomedical research: technological advances. Dis Model Mech 2019; 12:dmm029462. [PMID: 30626588 PMCID: PMC6361157 DOI: 10.1242/dmm.029462] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Over the past decade, new methods and procedures have been developed to generate genetically engineered mouse models of human disease. This At a Glance article highlights several recent technical advances in mouse genome manipulation that have transformed our ability to manipulate and study gene expression in the mouse. We discuss how conventional gene targeting by homologous recombination in embryonic stem cells has given way to more refined methods that enable allele-specific manipulation in zygotes. We also highlight advances in the use of programmable endonucleases that have greatly increased the feasibility and ease of editing the mouse genome. Together, these and other technologies provide researchers with the molecular tools to functionally annotate the mouse genome with greater fidelity and specificity, as well as to generate new mouse models using faster, simpler and less costly techniques.
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Affiliation(s)
- Channabasavaiah B Gurumurthy
- Developmental Neuroscience, Munroe Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, NE 68106-5915, USA
- Mouse Genome Engineering Core Facility, Vice Chancellor for Research Office, University of Nebraska Medical Center, Omaha, NE 68106-5915, USA
| | - Kevin C Kent Lloyd
- Department of Surgery, School of Medicine, University of California, Davis, CA 95618, USA
- Mouse Biology Program, University of California, Davis, CA 95618, USA
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6
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Tomioka I, Nogami N, Nakatani T, Owari K, Fujita N, Motohashi H, Takayama O, Takae K, Nagai Y, Seki K. Generation of transgenic marmosets using a tetracyclin-inducible transgene expression system as a neurodegenerative disease model. Biol Reprod 2018; 97:772-780. [PMID: 29045563 DOI: 10.1093/biolre/iox129] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/12/2017] [Indexed: 01/18/2023] Open
Abstract
Controllable transgene expression systems are indispensable tools for the production of animal models of disease to investigate protein functions at defined periods. However, in nonhuman primates that share genetic, physiological, and morphological similarities with humans, genetic modification techniques have not been well established; therefore, the establishment of novel transgenic models with controllable transgene expression systems will be valuable tools to understand pathological mechanism of human disease. In the present study, we successfully generated transgenic marmosets using a tetracyclin-inducible transgene expression (tet-on) system as a neurodegenerative disease model. The mutant human ataxin 3 gene controlled by the tet-on system was introduced into marmoset embryos via lentiviral transduction, and 34 transgene-introduced embryos were transferred into the uteri of surrogate mothers. Seven live offspring (TET1-7) were obtained, of which four were transgenic. Fibroblasts from TET1 and 3 revealed that inducible transgene expression had occurred after treatment with 10 μg/mL of doxycycline, while treatment with doxycycline via drinking water resulted in 1.7- to 1.8-fold inducible transgene expression compared with before treatment. One transgenic second-generation offspring (TET3-3) was obtained from TET3, and doxycycline-inducible transgene expression in its fibroblasts showed that TET3-3 maintained a high transgene expression level that matched its parent. In conclusion, we established a novel transgenic marmoset line carrying the mutant human ataxin 3 gene controlled by the tet-on system. The development of nonhuman primate models with controllable transgene expression systems will be useful for the identification of disease biomarkers and evaluation of the efficacy and metabolic profiles of therapeutic candidates.
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Affiliation(s)
- Ikuo Tomioka
- Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.,Institute for Biomedical Science, Shinshu University, Nagano, Japan
| | - Naotake Nogami
- Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Terumi Nakatani
- Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Kensuke Owari
- Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Naoko Fujita
- Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Hideyuki Motohashi
- Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Osamu Takayama
- Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Kentaro Takae
- Institute for Biomedical Science, Shinshu University, Nagano, Japan
| | - Yoshitaka Nagai
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.,Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Kazuhiko Seki
- Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
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7
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Kumar TR. Extragonadal Actions of FSH: A Critical Need for Novel Genetic Models. Endocrinology 2018; 159:2-8. [PMID: 29236987 PMCID: PMC5761596 DOI: 10.1210/en.2017-03118] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 11/14/2017] [Indexed: 12/11/2022]
Abstract
Follicle-stimulating hormone (FSH) is critical for ovarian folliculogenesis and essential for female fertility. FSH binds to FSH receptors (FSHRs) and regulates estrogen production in ovarian granulosa cells to orchestrate female reproductive physiology. Ovarian senescence that occurs as a function of aging results in loss of estrogen production, and this is believed to be the major reason for bone loss in postmenopausal women. Although conflicting, studies in rodents and humans during the last decade have provided genetic, pharmacological, and physiological evidence that elevated FSH levels that occur in the face of normal or declining estrogen levels directly regulate bone mass and adiposity. Recently, an efficacious blocking polyclonal FSHβ antibody was developed that inhibited ovariectomy-induced bone loss and triggered white-to-brown fat conversion accompanied by mitochondrial biogenesis in mice. Moreover, additional nongonadal targets of FSH action have been identified, and these include the female reproductive tract (endometrium and myometrium), the placenta, hepatocytes, and blood vessels. In this mini-review, I summarize these studies in mice and humans and discuss critical gaps in our knowledge, yet unanswered questions, and the rationale for developing novel genetic models to unambiguously address the extragonadal actions of FSH.
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Affiliation(s)
- T. Rajendra Kumar
- Division of Reproductive Sciences and Division of Reproductive Endocrinology & Infertility, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
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8
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Abstract
Heat shock transcription factors (Hsfs) regulate transcription of heat shock proteins as well as other genes whose promoters contain heat shock elements (HSEs). There are at least five Hsfs in mammalian cells, Hsf1, Hsf2, Hsf3, Hsf4, and Hsfy (Wu, Annu Rev Cell Dev Biol 11:441-469, 1995; Morimoto, Genes Dev 12:3788-3796, 1998; Tessari et al., Mol Hum Repord 4:253-258, 2004; Fujimoto et al., Mol Biol Cell 21:106-116, 2010; Nakai et al., Mol Cell Biol 17:469-481, 1997; Sarge et al., Genes Dev 5:1902-1911, 1991). To understand the physiological roles of Hsf1, Hsf2, and Hsf4 in vivo, we generated knockout mouse lines for these factors (Zhang et al., J Cell Biochem 86:376-393, 2002; Wang et al., Genesis 36:48-61, 2003; Min et al., Genesis 40:205-217, 2004). Numbers of other laboratories have also generated Hsf1 (Xiao et al., EMBO J 18:5943-5952, 1999; Sugahara et al., Hear Res 182:88-96, 2003), Hsf2 (McMillan et al., Mol Cell Biol 22:8005-8014, 2002; Kallio et al., EMBO J 21:2591-2601, 2002), and Hsf4 (Fujimoto et al., EMBO J 23:4297-4306, 2004) knockout mouse models. In this chapter, we describe the design of the targeting vectors, the plasmids used, and the successful generation of mice lacking the individual genes. We also briefly describe what we have learned about the physiological functions of these genes in vivo.
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Affiliation(s)
- Xiongjie Jin
- Molecular Chaperone Biology, Medical College of Georgia, Augusta University, Georgia Cancer Center, 1410 Laney Walker Blvd., CN3141, Augusta, GA, 30912, USA
| | - Binnur Eroglu
- Molecular Chaperone Biology, Medical College of Georgia, Augusta University, Georgia Cancer Center, 1410 Laney Walker Blvd., CN3141, Augusta, GA, 30912, USA
| | - Demetrius Moskophidis
- Molecular Chaperone Biology, Medical College of Georgia, Augusta University, Georgia Cancer Center, 1410 Laney Walker Blvd., CN3141, Augusta, GA, 30912, USA
| | - Nahid F Mivechi
- Molecular Chaperone Biology, Medical College of Georgia, Augusta University, Georgia Cancer Center, 1410 Laney Walker Blvd., CN3141, Augusta, GA, 30912, USA.
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9
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A mouse retinal explant model for use in studying neuroprotection in glaucoma. Exp Eye Res 2016; 151:38-44. [DOI: 10.1016/j.exer.2016.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 06/30/2016] [Accepted: 07/16/2016] [Indexed: 11/17/2022]
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10
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Abstract
Liver regeneration has been studied for many decades and the mechanisms underlying regeneration of the normal liver following resection or moderate damage are well described. A large number of factors extrinsic (such as bile acids and circulating growth factors) and intrinsic to the liver interact to initiate and regulate liver regeneration. Less well understood, and more clinically relevant, are the factors at play when the abnormal liver is required to regenerate. Fatty liver disease, chronic scarring, prior chemotherapy and massive liver injury can all inhibit the normal programme of regeneration and can lead to liver failure. Understanding these mechanisms could enable the rational targeting of specific therapies to either reduce the factors inhibiting regeneration or directly stimulate liver regeneration. Although animal models of liver regeneration have been highly instructive, the clinical relevance of some models could be improved to bridge the gap between our in vivo model systems and the clinical situation. Likewise, modern imaging techniques such as spectroscopy will probably improve our understanding of whole-organ metabolism and how this predicts the liver's regenerative capacity. This Review describes briefly the mechanisms underpinning liver regeneration, the models used to study this process, and discusses areas in which failed or compromised liver regeneration is clinically relevant.
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Affiliation(s)
- Stuart J Forbes
- MRC Centre for Regenerative Medicine, 5 Little France Drive, University of Edinburgh, Edinburgh EH16 4UU, UK
| | - Philip N Newsome
- Birmingham National Institute for Health Research (NIHR) Liver Biomedical Research Unit and Centre for Liver Research, University of Birmingham, Vincent Drive Birmingham, B15 2TT, UK
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11
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Ansell DM, Campbell L, Thomason HA, Brass A, Hardman MJ. A statistical analysis of murine incisional and excisional acute wound models. Wound Repair Regen 2014; 22:281-7. [PMID: 24635179 PMCID: PMC4309476 DOI: 10.1111/wrr.12148] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 12/21/2013] [Indexed: 01/17/2023]
Abstract
Mice represent the most commonly used species for preclinical in vivo research. While incisional and excisional acute murine wound models are both frequently employed, there is little agreement on which model is optimum. Moreover, current lack of standardization of wounding procedure, analysis time point(s), method of assessment, and the use of individual wounds vs. individual animals as replicates makes it difficult to compare across studies. Here we have profiled secondary intention healing of incisional and excisional wounds within the same animal, assessing multiple parameters to determine the optimal methodology for future studies. We report that histology provides the least variable assessment of healing. Furthermore, histology alone (not planimetry) is able to detect accelerated healing in a castrated mouse model. Perhaps most importantly, we find virtually no correlation between wounds within the same animal, suggesting that use of wound (not animal) biological replicates is perfectly acceptable. Overall, these findings should guide and refine future studies, increasing the likelihood of detecting novel phenotypes while reducing the numbers of animals required for experimentation.
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Affiliation(s)
- David M Ansell
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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12
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Abstract
Current dogma is that mouse primordial germ cells (PGCs) segregate within the allantois, or source of the umbilical cord, and translocate to the gonads, differentiating there into sperm and eggs. In light of emerging data on the posterior embryonic-extraembryonic interface, and the poorly studied but vital fetal-umbilical connection, we have reviewed the past century of experiments on mammalian PGCs and their relation to the allantois. We demonstrate that, despite best efforts and valuable data on the pluripotent state, what is and is not a PGC in vivo is obscure. Furthermore, sufficient experimental evidence has yet to be provided either for an extragonadal origin of mammalian PGCs or for their segregation within the posterior region. Rather, most evidence points to an alternative hypothesis that PGCs in the mouse allantois are part of a stem/progenitor cell pool that exhibits all known PGC "markers" and that builds/reinforces the fetal-umbilical interface, common to amniotes. We conclude by suggesting experiments to distinguish the mammalian germ line from the soma.
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13
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Tian YG, Yue M, Gu Y, Gu WW, Wang YJ. Single-nucleotide polymorphism analysis of GH, GHR, and IGF-1 genes in minipigs. ACTA ACUST UNITED AC 2014; 47:753-8. [PMID: 25098617 PMCID: PMC4143202 DOI: 10.1590/1414-431x20143945] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 05/12/2014] [Indexed: 11/22/2022]
Abstract
Tibetan (TB) and Bama (BM) miniature pigs are two popular pig breeds that are used as experimental animals in China due to their small body size. Here, we analyzed single-nucleotide polymorphisms (SNPs) in gene fragments that are closely related to growth traits [growth hormone (GH), growth hormone receptor (GHR), and insulin-like growth factor (IGF)-1)] in these pig breeds and a large white (LW) control pig breed. On the basis of the analysis of 100 BMs, 108 TBs, and 50 LWs, the polymorphic distribution levels of GH, GHR, and IGF-1 were significantly different among these three pig breeds. According to correlation analyses between SNPs and five growth traits--body weight (BW), body length (BL), withers height (WH), chest circumference (CC), and abdomen circumference (AC)--three SNP loci in BMs and four SNP loci in TBs significantly affected growth traits. Three SNP sites in BMs and four SNP sites in TBs significantly affected growth traits. SNPs located in the GH gene fragment significantly affected BL and CC at locus 12 and BL at locus 45 in BMs, and also BW, WH, CC, and AC at locus 45 and WH and CC at locus 93 in TBs. One SNP at locus 85 in the BM GHR gene fragment significantly affected all growth traits. All indices were significantly reduced with a mixture of alleles at locus 85. These results provide more information regarding the genetic background of these minipig species and indicate useful selection markers for pig breeding programs.
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Affiliation(s)
- Y G Tian
- Laboratory Animal Center, Southern Medical University, Guangzhou, Guangdong, China
| | - M Yue
- Laboratory Animal Center, Southern Medical University, Guangzhou, Guangdong, China
| | - Y Gu
- Laboratory Animal Center, Southern Medical University, Guangzhou, Guangdong, China
| | - W W Gu
- Laboratory Animal Center, Southern Medical University, Guangzhou, Guangdong, China
| | - Y J Wang
- Laboratory Animal Center, Southern Medical University, Guangzhou, Guangdong, China
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14
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Jin YX, Jeon Y, Lee SH, Kwon MS, Kim T, Cui XS, Hyun SH, Kim NH. Production of pigs expressing a transgene under the control of a tetracycline-inducible system. PLoS One 2014; 9:e86146. [PMID: 24454957 PMCID: PMC3893280 DOI: 10.1371/journal.pone.0086146] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Accepted: 12/06/2013] [Indexed: 11/21/2022] Open
Abstract
Pigs are anatomically and physiologically closer to humans than other laboratory animals. Transgenic (TG) pigs are widely used as models of human diseases. The aim of this study was to produce pigs expressing a tetracycline (Tet)-inducible transgene. The Tet-on system was first tested in infected donor cells. Porcine fetal fibroblasts were infected with a universal doxycycline-inducible vector containing the target gene enhanced green fluorescent protein (eGFP). At 1 day after treatment with 1 µg/ml doxycycline, the fluorescence intensity of these cells was increased. Somatic cell nuclear transfer (SCNT) was then performed using these donor cells. The Tet-on system was then tested in the generated porcine SCNT-TG embryos. Of 4,951 porcine SCNT-TG embryos generated, 850 were cultured in the presence of 1 µg/ml doxycycline in vitro. All of these embryos expressed eGFP and 15 embryos developed to blastocyst stage. The remaining 4,101 embryos were transferred to thirty three surrogate pigs from which thirty eight cloned TG piglets were obtained. PCR analysis showed that the transgene was inserted into the genome of each of these piglets. Two TG fibroblast cell lines were established from these TG piglets, and these cells were used as donor cells for re-cloning. The re-cloned SCNT embryos expressed the eGFP transgene under the control of doxycycline. These data show that the expression of transgenes in cloned TG pigs can be regulated by the Tet-on/off systems.
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Affiliation(s)
- Yong-Xun Jin
- Department of Animal Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Yubyeol Jeon
- College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Sung-Hyun Lee
- Department of Animal Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Mo-Sun Kwon
- School of Medicine, Catholic University of Daegu, Daegu, Republic of Korea
| | - Teoan Kim
- School of Medicine, Catholic University of Daegu, Daegu, Republic of Korea
| | - Xiang-Shun Cui
- Department of Animal Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Sang-Hwan Hyun
- College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea
- * E-mail: (NHK); (SHH)
| | - Nam-Hyung Kim
- Department of Animal Science, Chungbuk National University, Cheongju, Republic of Korea
- * E-mail: (NHK); (SHH)
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15
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Retina-specific gene excision by targeted expression of Cre recombinase. Biochem Biophys Res Commun 2013; 441:777-81. [PMID: 24211578 DOI: 10.1016/j.bbrc.2013.10.139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 10/25/2013] [Indexed: 10/26/2022]
Abstract
The use of Cre recombinase for conditional targeting permits the controlled removal or activation of genes in specific tissues and at specific times of development. The Rho-Cre mice provide an improved tool for studying gene ablation in rod photoreceptor cells. To establish a robust expression of Rho-Cre transgenic mice that would be useful for the study of various protein functions in photoreceptor cells, a total 11,987 kb fragment (pNCHS4 Rho-NLS-cre) containing human rhodopsin promoter was cloned. The Rho-Cre plasmid was digested with EcoR1 and I Ceu-1, and the 9.316 kb fragment containing the hRho promoter and Cre recombinase gel was purified. To generate transgenic mice, the purified DNA fragment was injected into fertilized oocytes according to standard protocols. ROSA26R reported the steady expression of Rho-Cre especially in photoreceptor cells, allowing further excising proteins in rod photoreceptors across the retina. This Rho-Cre transgenic line should thus prove useful as a general deletor line for genetic analysis of diverse aspects of retinopathy.
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Cabezas-Wallscheid N, Eichwald V, de Graaf J, Löwer M, Lehr HA, Kreft A, Eshkind L, Hildebrandt A, Abassi Y, Heck R, Dehof AK, Ohngemach S, Sprengel R, Wörtge S, Schmitt S, Lotz J, Meyer C, Kindler T, Zhang DE, Kaina B, Castle JC, Trumpp A, Sahin U, Bockamp E. Instruction of haematopoietic lineage choices, evolution of transcriptional landscapes and cancer stem cell hierarchies derived from an AML1-ETO mouse model. EMBO Mol Med 2013; 5:1804-20. [PMID: 24124051 PMCID: PMC3914523 DOI: 10.1002/emmm.201302661] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 08/28/2013] [Accepted: 08/28/2013] [Indexed: 11/11/2022] Open
Abstract
The t(8;21) chromosomal translocation activates aberrant expression of the AML1-ETO (AE) fusion protein and is commonly associated with core binding factor acute myeloid leukaemia (CBF AML). Combining a conditional mouse model that closely resembles the slow evolution and the mosaic AE expression pattern of human t(8;21) CBF AML with global transcriptome sequencing, we find that disease progression was characterized by two principal pathogenic mechanisms. Initially, AE expression modified the lineage potential of haematopoietic stem cells (HSCs), resulting in the selective expansion of the myeloid compartment at the expense of normal erythro- and lymphopoiesis. This lineage skewing was followed by a second substantial rewiring of transcriptional networks occurring in the trajectory to manifest leukaemia. We also find that both HSC and lineage-restricted granulocyte macrophage progenitors (GMPs) acquired leukaemic stem cell (LSC) potential being capable of initiating and maintaining the disease. Finally, our data demonstrate that long-term expression of AE induces an indolent myeloproliferative disease (MPD)-like myeloid leukaemia phenotype with complete penetrance and that acute inactivation of AE function is a potential novel therapeutic option.
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Affiliation(s)
- Nina Cabezas-Wallscheid
- Medical Center of the Johannes Gutenberg-University Mainz, Department of Internal Medicine III, Division of Translational and Experimental Oncology, Mainz, Germany; German Cancer Research Center, Department of Stem Cells and Cancer, Heidelberg, Germany; Medical Center of the Johannes Gutenberg-University Mainz, Institute for Toxicology, Mainz, Germany
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Calaminus SDJ, Guitart A, Sinclair A, Schachtner H, Watson SP, Holyoake TL, Kranc KR, Machesky LM. Lineage tracing of Pf4-Cre marks hematopoietic stem cells and their progeny. PLoS One 2012; 7:e51361. [PMID: 23300543 PMCID: PMC3531453 DOI: 10.1371/journal.pone.0051361] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 11/07/2012] [Indexed: 11/19/2022] Open
Abstract
The development of a megakaryocyte lineage specific Cre deleter, using the Pf4 (CXCL4) promoter (Pf4-Cre), was a significant step forward in the specific analysis of platelet and megakaryocyte cell biology. However, in the present study we have employed a sensitive reporter-based approach to demonstrate that Pf4-Cre also recombines in a significant proportion of both fetal liver and bone marrow hematopoietic stem cells (HSCs), including the most primitive fraction containing the long-term repopulating HSCs. Consequently, we demonstrate that Pf4-Cre activity is not megakaryocyte lineage-specific but extends to other myeloid and lymphoid lineages at significant levels between 15-60%. Finally, we show for the first time that Pf4 transcripts are present in adult HSCs and primitive hematopoietic progenitor cells. These results have fundamental implications for the use of the Pf4-Cre mouse model and for our understanding of a possible role for Pf4 in the development of the hematopoietic lineage.
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Affiliation(s)
- Simon D. J. Calaminus
- Beatson Institute for Cancer Research, University of Glasgow, Glasgow, United Kingdom
| | - Amelie Guitart
- Paul O’Gorman Leukaemia Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Amy Sinclair
- Paul O’Gorman Leukaemia Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Hannah Schachtner
- Beatson Institute for Cancer Research, University of Glasgow, Glasgow, United Kingdom
| | - Steve P. Watson
- Centre for Cardiovascular Sciences, Institute for Biomedical Research, University of Birmingham, Birmingham, United Kingdom
| | - Tessa L. Holyoake
- Paul O’Gorman Leukaemia Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kamil R. Kranc
- Paul O’Gorman Leukaemia Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Laura M. Machesky
- Beatson Institute for Cancer Research, University of Glasgow, Glasgow, United Kingdom
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Jiang BC, Yu DB, Wang LJ, Dong FL, Kaleri HA, Wang XG, Ally N, Li J, Liu HL. Doxycycline-regulated growth hormone gene expression system for swine. GENETICS AND MOLECULAR RESEARCH 2012; 11:2946-57. [PMID: 22869070 DOI: 10.4238/2012.july.10.5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although growth hormone gene transgenic animals are much larger than normal animals, they manifest differences that have adverse effects on survival due to overexpression of growth hormone. We developed a stable pig embryonic fibroblast cell line expressing pig growth hormone (pGH) using the Tet-On system, with which we can conditionally manipulate expression of pGH in vivo. Inducible expression of pGH was achieved by combining reserve Tet-controlled transcriptional activator and tetracycline-responsive element in a single plasmid. The mRNA expression of pGH was significantly increased compared to the non-induced group by about 10-fold. The controlled secretion of pGH induced by doxycycline was further tested in stably transfected cells. We conclude that inducible GH expression can be achieved in pig embryonic fibroblasts.
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Affiliation(s)
- B C Jiang
- Department of Animal Breeding & Genetics, College of Animal Science & Technology, Nanjing Agricultural University, Nanjing, China
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Eliyahu E, Shtraizent N, Shalgi R, Schuchman EH. Construction of conditional acid ceramidase knockout mice and in vivo effects on oocyte development and fertility. Cell Physiol Biochem 2012; 30:735-48. [PMID: 22854249 DOI: 10.1159/000341453] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2012] [Indexed: 12/14/2022] Open
Abstract
The number of resting follicles in the ovary and their successful maturation during development define the fertile female lifespan. Oocytes, enclosed within follicles, are subject to natural selection, and the majority will undergo apoptosis during prenatal life through adulthood. Our previous studies revealed high levels of the lipid hydrolase, acid ceramidase (AC), in human and mouse oocytes, follicular fluid and cumulus cells. In addition, supplementation of in vitro fertilization media with recombinant AC enhanced the survival of oocytes and preimplantation embryos. Herein we constructed and used a conditional knockout mouse model of AC deficiency (cACKO) to further investigate the role of this enzyme in oocyte survival in vivo. Immunohistochemical staining, activity assays, and western blot analysis revealed that AC expression was high in the ovaries of normal mice, particularly in the theca cells. After induction of the AC gene knockout with tamoxifen (TM), AC levels decreased in ovaries, and ceramide was correspondingly elevated. A novel immunostaining method was developed to visualize follicles at various stages, and together with light microscopic examination, the transition of the follicle from the secondary to antral stage was found to be defective in the absence of AC. Western blot analysis showed elevated BAX and PARP expression in TM-treated cACKO mouse ovaries compared to control animals. In parallel, the levels of BCL-2 and anti-Mullerian hormone, a marker of ovarian reserve, were decreased. In addition to the above, there was a significant decrease in fertility observed in the TM-treated cACKO mice. Together, these data suggest that AC plays an important role in the preservation of fertility by maintaining low ceramide levels and preventing apoptosis of theca cells, thereby promoting survival of the follicle during the transition from the secondary to antral stage.
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Affiliation(s)
- Efrat Eliyahu
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, 1425 Madison Avenue, Room 14-20A, New York, NY, USA
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Affiliation(s)
- David M. Ansell
- The Healing Foundation Centre; Faculty of Life Sciences; The University of Manchester; Manchester; UK
| | | | - Matthew J. Hardman
- The Healing Foundation Centre; Faculty of Life Sciences; The University of Manchester; Manchester; UK
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Functions and physiological roles of two types of estrogen receptors, ERα and ERβ, identified by estrogen receptor knockout mouse. Lab Anim Res 2012; 28:71-6. [PMID: 22787479 PMCID: PMC3389841 DOI: 10.5625/lar.2012.28.2.71] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 05/21/2012] [Accepted: 05/25/2012] [Indexed: 01/23/2023] Open
Abstract
Estrogens, a class of steroid hormones, regulate the growth, development, and physiology of the human reproductive system. Estrogens also involve in the neuroendocrine, skeletal, adipogenesis, and cardiovascular systems. Estrogen signaling pathways are selectively stimulated or inhibited depending on a balance between the activities of estrogen receptor (ER) α or ERβ in target organs. ERs belong to the steroid hormone superfamily of nuclear receptors, which act as transcription factors after binding to estrogen. The gene expression regulation by ERs is to modulate biological activities, such as reproductive organ development, bone modeling, cardiovascular system functioning, metabolism, and behavior in both females and males. Understanding of the general physiological roles of ERs has been gained when estrogen levels were ablated by ovariectomy and then replenished by treatment with exogenous estrogen. This technique is not sufficient to fully determine the exact function of estrogen signaling in general processes in living tissues. However, a transgenic mouse model has been useful to study gene-specific functions. ERα and ERβ have different biological functions, and knockout and transgenic animal models have distinct phenotypes. Analysis of ERα and ERβ function using knockout mouse models has identified the roles of estrogen signaling in general physiologic processes. Although transgenic mouse models do not always produce consistent results, they are the useful for studying the functions of these genes under specific pathological conditions.
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22
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Benenson Y. Biomolecular computing systems: principles, progress and potential. Nat Rev Genet 2012; 13:455-68. [PMID: 22688678 DOI: 10.1038/nrg3197] [Citation(s) in RCA: 219] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The task of information processing, or computation, can be performed by natural and man-made 'devices'. Man-made computers are made from silicon chips, whereas natural 'computers', such as the brain, use cells and molecules. Computation also occurs on a much smaller scale in regulatory and signalling pathways in individual cells and even within single biomolecules. Indeed, much of what we recognize as life results from the remarkable capacity of biological building blocks to compute in highly sophisticated ways. Rational design and engineering of biological computing systems can greatly enhance our ability to study and to control biological systems. Potential applications include tissue engineering and regeneration and medical treatments. This Review introduces key concepts and discusses recent progress that has been made in biomolecular computing.
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Affiliation(s)
- Yaakov Benenson
- Department of Biosystems Science and Engineering, Swiss Federal Institute of Technology (ETH Zurich), Mattenstrasse 26, 4058 Basel, Switzerland.
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23
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Animal Models in Cardiovascular MRI Research: Value and Limitations. CURRENT CARDIOVASCULAR IMAGING REPORTS 2012. [DOI: 10.1007/s12410-012-9128-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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24
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The human ubiquitin C promoter drives selective expression in principal neurons in the brain of a transgenic mouse line. Neurochem Int 2011; 59:976-80. [DOI: 10.1016/j.neuint.2011.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 07/13/2011] [Indexed: 01/26/2023]
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Protein delivery using engineered virus-like particles. Proc Natl Acad Sci U S A 2011; 108:16998-7003. [PMID: 21949376 DOI: 10.1073/pnas.1101874108] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Over the years, researchers have developed several methods to deliver macromolecules into the cytosol and nucleus of living cells. However, there are limitations to all of these methods. The problems include (i) inefficient uptake, (ii) endosomal entrapment, (iii) delivery that is restricted to certain cell types, and (iv) damage to cells in the delivery process. Retroviral vectors are often used for gene delivery; however, integration of the genome of retroviral vector into the host genome can have serious consequences. Here we describe a safe alternative in which virus-like particles (VLPs), derived from an avian retrovirus, are used to deliver protein to cells. We show that these VLPs are a highly adaptable platform that can be used to deliver proteins either as part of Gag fusion proteins (intracellular delivery) or on the surface of VLPs. We generated VLPs that contain Gag-Cre recombinase, Gag-Fcy::Fur, and Gag-human caspase-8 as a proof-of-concept and demonstrated that the encapsidated proteins are active in recipient cells. In addition, we show that murine IFN-γ and human TNF-related apoptosis-inducing ligand can be displayed on the surface of VLPs, and that these modified VLPs can cause the appropriate response in cells, as evidenced by phosphorylation of STAT1 and induction of cell death, respectively.
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26
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Gibney BC, Lee GS, Houdek JP, Lin M, Miele LF, Chamoto K, Konerding MA, Tsuda A, Mentzer SJ. Dynamic determination of oxygenation and lung compliance in murine pneumonectomy. Exp Lung Res 2011; 37:301-9. [PMID: 21574875 DOI: 10.3109/01902148.2011.561399] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Thoracic surgical procedures in mice have been applied to a wide range of investigations, but little is known about the murine physiologic response to pulmonary surgery. Using continuous arterial oximetry monitoring and the FlexiVent murine ventilator, the authors investigated the effect of anesthesia and pneumonectomy on mouse oxygen saturation and lung mechanics. Sedation resulted in a dose-dependent decline of oxygen saturation that ranged from 55% to 82%. Oxygen saturation was restored by mechanical ventilation with increased rate and tidal volumes. In the mouse strain studied, optimal ventilatory rates were a rate of 200/minute and a tidal volume of 10 mL/kg. Sustained inflation pressures, referred to as a "recruitment maneuver," improved lung volumes, lung compliance, and arterial oxygenation. In contrast, positive end-expiratory pressure (PEEP) had a detrimental effect on oxygenation; an effect that was ameliorated after pneumonectomy. These results confirm that lung volumes in the mouse are dynamically determined and suggest a threshold level of mechanical ventilation to maintain perioperative oxygen saturation.
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Affiliation(s)
- Barry C Gibney
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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27
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Farley EK, Gale E, Chambers D, Li M. Effects of in ovo electroporation on endogenous gene expression: genome-wide analysis. Neural Dev 2011; 6:17. [PMID: 21527010 PMCID: PMC3105949 DOI: 10.1186/1749-8104-6-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 04/28/2011] [Indexed: 11/23/2022] Open
Abstract
Background In ovo electroporation is a widely used technique to study gene function in developmental biology. Despite the widespread acceptance of this technique, no genome-wide analysis of the effects of in ovo electroporation, principally the current applied across the tissue and exogenous vector DNA introduced, on endogenous gene expression has been undertaken. Here, the effects of electric current and expression of a GFP-containing construct, via electroporation into the midbrain of Hamburger-Hamilton stage 10 chicken embryos, are analysed by microarray. Results Both current alone and in combination with exogenous DNA expression have a small but reproducible effect on endogenous gene expression, changing the expression of the genes represented on the array by less than 0.1% (current) and less than 0.5% (current + DNA), respectively. The subset of genes regulated by electric current and exogenous DNA span a disparate set of cellular functions. However, no genes involved in the regional identity were affected. In sharp contrast to this, electroporation of a known transcription factor, Dmrt5, caused a much greater change in gene expression. Conclusions These findings represent the first systematic genome-wide analysis of the effects of in ovo electroporation on gene expression during embryonic development. The analysis reveals that this process has minimal impact on the genetic basis of cell fate specification. Thus, the study demonstrates the validity of the in ovo electroporation technique to study gene function and expression during development. Furthermore, the data presented here can be used as a resource to refine the set of transcriptional responders in future in ovo electroporation studies of specific gene function.
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Affiliation(s)
- Emma K Farley
- MRC Clinical Sciences Centre, Imperial College London, W12 0NN, UK.
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Abstract
Heat-shock transcription factors (Hsfs) regulate transcription of heat-shock proteins as well as other genes whose promoters contain heat-shock elements. There are at least five Hsfs in mammalian cells, Hsf1, Hsf2, Hsf3, Hsf4, and Hsfy. To understand the physiological roles of Hsf1, Hsf2, and Hsf4 in vivo, we generated knockout mouse lines for these factors. In this chapter, we describe the design of the targeting vectors, the plasmids used, and the successful generation of mice lacking the individual genes. We also briefly describe what we have learned about the physiological functions of these genes in vivo.
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Affiliation(s)
- Xiongjie Jin
- Center for Molecular Chaperone/Radiobiology and Cancer Virology, Medical College of Georgia, Augusta, GA, USA
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29
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Wörtge S, Eshkind L, Cabezas-Wallscheid N, Lakaye B, Kim J, Heck R, Abassi Y, Diken M, Sprengel R, Bockamp E. Tetracycline-controlled transgene activation using the ROSA26-iM2-GFP knock-in mouse strain permits GFP monitoring of DOX-regulated transgene-expression. BMC DEVELOPMENTAL BIOLOGY 2010; 10:95. [PMID: 20815887 PMCID: PMC2944160 DOI: 10.1186/1471-213x-10-95] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 09/03/2010] [Indexed: 12/21/2022]
Abstract
Background Conditional gene activation is an efficient strategy for studying gene function in genetically modified animals. Among the presently available gene switches, the tetracycline-regulated system has attracted considerable interest because of its unique potential for reversible and adjustable gene regulation. Results To investigate whether the ubiquitously expressed Gt(ROSA)26Sor locus enables uniform DOX-controlled gene expression, we inserted the improved tetracycline-regulated transcription activator iM2 together with an iM2 dependent GFP gene into the Gt(ROSA)26Sor locus, using gene targeting to generate ROSA26-iM2-GFP (R26t1Δ) mice. Despite the presence of ROSA26 promoter driven iM2, R26t1Δ mice showed very sparse DOX-activated expression of different iM2-responsive reporter genes in the brain, mosaic expression in peripheral tissues and more prominent expression in erythroid, myeloid and lymphoid lineages, in hematopoietic stem and progenitor cells and in olfactory neurons. Conclusions The finding that gene regulation by the DOX-activated transcriptional factor iM2 in the Gt(ROSA)26Sor locus has its limitations is of importance for future experimental strategies involving transgene activation from the endogenous ROSA26 promoter. Furthermore, our ROSA26-iM2 knock-in mouse model (R26t1Δ) represents a useful tool for implementing gene function in vivo especially under circumstances requiring the side-by-side comparison of gene manipulated and wild type cells. Since the ROSA26-iM2 mouse allows mosaic gene activation in peripheral tissues and haematopoietic cells, this model will be very useful for uncovering previously unknown or unsuspected phenotypes.
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Affiliation(s)
- Simone Wörtge
- Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
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Sharov AA, Piao Y, Ko MSH. Gene expression profiling of mouse embryos with microarrays. Methods Enzymol 2010; 477:511-41. [PMID: 20699157 DOI: 10.1016/s0076-6879(10)77025-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Global expression profiling by DNA microarrays provides a snapshot of cell and tissue status and becomes an essential tool in biological and medical sciences. Typical questions that can be addressed by microarray analysis in developmental biology include: (1) to find a set of genes expressed in a specific cell type; (2) to identify genes expressed commonly in multiple cell types; (3) to follow the time-course changes of gene expression patterns; (4) to demonstrate cell's identity by showing similarities or differences among two or multiple cell types; (5) to find regulatory pathways and/or networks affected by gene manipulations, such as overexpression or repression of gene expression; (6) to find downstream target genes of transcription factors; (7) to find downstream target genes of cell signaling; (8) to examine the effects of environmental manipulation of cells on gene expression patterns; and (9) to find the effects of genetic manipulation in embryos and adults. Here, we describe strategies for executing these experiments and monitoring changes of cell state with gene expression microarrays in application to mouse embryology. Both statistical assessment and interpretation of data are discussed. We also present a protocol for performing microarray analysis on a small amount of embryonic materials.
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Affiliation(s)
- Alexei A Sharov
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, NIH, Baltimore, Maryland, USA
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Abstract
Mouse models of human cancer have played a vital role in understanding tumorigenesis and answering experimental questions that other systems cannot address. Advances continue to be made that allow better understanding of the mechanisms of tumor development, and therefore the identification of better therapeutic and diagnostic strategies. We review major advances that have been made in modeling cancer in the mouse and specific areas of research that have been explored with mouse models. For example, although there are differences between mice and humans, new models are able to more accurately model sporadic human cancers by specifically controlling timing and location of mutations, even within single cells. As hypotheses are developed in human and cell culture systems, engineered mice provide the most tractable and accurate test of their validity in vivo. For example, largely through the use of these models, the microenvironment has been established to play a critical role in tumorigenesis, since tumor development and the interaction with surrounding stroma can be studied as both evolve. These mouse models have specifically fueled our understanding of cancer initiation, immune system roles, tumor angiogenesis, invasion, and metastasis, and the relevance of molecular diversity observed among human cancers. Currently, these models are being designed to facilitate in vivo imaging to track both primary and metastatic tumor development from much earlier stages than previously possible. Finally, the approaches developed in this field to achieve basic understanding are emerging as effective tools to guide much needed development of treatment strategies, diagnostic strategies, and patient stratification strategies in clinical research.
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Affiliation(s)
- Jessica C Walrath
- Mouse Cancer Genetics Program, National Cancer Institute, Frederick, Maryland, USA
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Hirrlinger J, Requardt RP, Winkler U, Wilhelm F, Schulze C, Hirrlinger PG. Split-CreERT2: temporal control of DNA recombination mediated by split-Cre protein fragment complementation. PLoS One 2009; 4:e8354. [PMID: 20016782 PMCID: PMC2791205 DOI: 10.1371/journal.pone.0008354] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Accepted: 11/26/2009] [Indexed: 01/05/2023] Open
Abstract
Background DNA recombination technologies such as the Cre/LoxP system advance modern biological research by allowing conditional gene regulation in vivo. However, the precise targeting of a particular cell type at a given time point has remained challenging since spatial specificity has so far depended exclusively on the promoter driving Cre recombinase expression. We have recently established split-Cre that allows DNA recombination to be controlled by coincidental activity of two promoters, thereby increasing spatial specificity of Cre-mediated DNA recombination. To allow temporal control of split-Cre-mediated DNA recombination we have now extended split-Cre by fusing split-Cre proteins with the tamoxifen inducible ERT2 domain derived from CreERT2. Methodology/Principal Findings In the split-CreERT2 system, Cre-mediated DNA recombination is controlled by two expression cassettes as well as the time of tamoxifen application. By using two independent Cre-dependent reporters in cultured cells, the combination of NCre-ERT2+ERT2-CCre was identified as having the most favorable properties of all constructs tested, showing an induction ratio of about 10 and EC50-values for 4-hydroxy-tamoxifen of 10 nM to 70 nM. Conclusions/Significance These characteristics of split-CreERT2 in vitro indicate that split-CreERT2 will be well suited for inducing DNA recombination in living mice harboring LoxP-flanked alleles. In this way, split-CreERT2 will provide a new tool of modern genetics allowing spatial and temporal precise genetic access to cell populations defined by the simultaneous activity of two promoters.
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Affiliation(s)
- Johannes Hirrlinger
- N05 Neural Plasticity, Interdisciplinary Centre for Clinical Research (IZKF), University of Leipzig, Leipzig, Germany.
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Zhu P, Narita Y, Bundschuh ST, Fajardo O, Schärer YPZ, Chattopadhyaya B, Bouldoires EA, Stepien AE, Deisseroth K, Arber S, Sprengel R, Rijli FM, Friedrich RW. Optogenetic Dissection of Neuronal Circuits in Zebrafish using Viral Gene Transfer and the Tet System. Front Neural Circuits 2009; 3:21. [PMID: 20126518 PMCID: PMC2805431 DOI: 10.3389/neuro.04.021.2009] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 11/27/2009] [Indexed: 01/07/2023] Open
Abstract
The conditional expression of transgenes at high levels in sparse and specific populations of neurons is important for high-resolution optogenetic analyses of neuronal circuits. We explored two complementary methods, viral gene delivery and the iTet-Off system, to express transgenes in the brain of zebrafish. High-level gene expression in neurons was achieved by Sindbis and Rabies viruses. The Tet system produced strong and specific gene expression that could be modulated conveniently by doxycycline. Moreover, transgenic lines showed expression in distinct, sparse and stable populations of neurons that appeared to be subsets of the neurons targeted by the promoter driving the Tet-activator. The Tet system therefore provides the opportunity to generate libraries of diverse expression patterns similar to gene trap approaches or the thy-1 promoter in mice, but with the additional possibility to pre-select cell types of interest. In transgenic lines expressing channelrhodopsin-2, action potential firing could be precisely controlled by two-photon stimulation at low laser power, presumably because the expression levels of the Tet-controlled genes were high even in adults. In channelrhodopsin-2-expressing larvae, optical stimulation with a single blue LED evoked distinct swimming behaviors including backward swimming. These approaches provide new opportunities for the optogenetic dissection of neuronal circuit structure and function.
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Affiliation(s)
- Peixin Zhu
- Friedrich Miescher Institute for Biomedical Research, Novartis Research Foundation Basel, Switzerland
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Caballero I, Piedrahita JA. Evaluation of theSerratia MarcescensNuclease (NucA) as a Transgenic Cell Ablation System in Porcine. Anim Biotechnol 2009; 20:177-85. [DOI: 10.1080/10495390903048235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Hirrlinger J, Scheller A, Hirrlinger PG, Kellert B, Tang W, Wehr MC, Goebbels S, Reichenbach A, Sprengel R, Rossner MJ, Kirchhoff F. Split-cre complementation indicates coincident activity of different genes in vivo. PLoS One 2009; 4:e4286. [PMID: 19172189 PMCID: PMC2628726 DOI: 10.1371/journal.pone.0004286] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Accepted: 12/12/2008] [Indexed: 11/19/2022] Open
Abstract
Cre/LoxP recombination is the gold standard for conditional gene regulation in mice in vivo. However, promoters driving the expression of Cre recombinase are often active in a wide range of cell types and therefore unsuited to target more specific subsets of cells. To overcome this limitation, we designed inactive "split-Cre" fragments that regain Cre activity when overlapping co-expression is controlled by two different promoters. Using transgenic mice and virus-mediated expression of split-Cre, we show that efficient reporter gene activation is achieved in vivo. In the brain of transgenic mice, we genetically defined a subgroup of glial progenitor cells in which the Plp1- and the Gfap-promoter are simultaneously active, giving rise to both astrocytes and NG2-positive glia. Similarly, a subset of interneurons was labelled after viral transfection using Gad67- and Cck1 promoters to express split-Cre. Thus, split-Cre mediated genomic recombination constitutes a powerful spatial and temporal coincidence detector for in vivo targeting.
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Affiliation(s)
- Johannes Hirrlinger
- Interdisciplinary Centre for Clinical Research (IZKF), N05 Neural Plasticity, Faculty of Medicine, University of Leipzig, Leipzig, Germany
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain, Göttingen, Germany
- * E-mail: (JH); (FK)
| | - Anja Scheller
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Section of Biology, Chemistry and Pharmacy, Free University of Berlin, Berlin, Germany
| | - Petra G. Hirrlinger
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Paul Flechsig Institute for Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Beate Kellert
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Wannan Tang
- Department of Molecular Neurobiology, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Michael C. Wehr
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Andreas Reichenbach
- Paul Flechsig Institute for Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Rolf Sprengel
- Department of Molecular Neurobiology, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Moritz J. Rossner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Frank Kirchhoff
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain, Göttingen, Germany
- * E-mail: (JH); (FK)
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