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Filice F, Blum W, Lauber E, Schwaller B. Inducible and reversible silencing of the Pvalb gene in mice: An in vitro and in vivo study. Eur J Neurosci 2019; 50:2694-2706. [PMID: 30883994 DOI: 10.1111/ejn.14404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 02/25/2019] [Accepted: 03/04/2019] [Indexed: 01/08/2023]
Abstract
Inducible and reversible regulation of gene expression is a powerful approach for unraveling gene functions. Here, we describe the generation of a system to efficiently downregulate in a reversible and inducible manner the Pvalb gene coding for the calcium-binding protein parvalbumin (PV) in mice. We made use of an IPTG-inducible short hairpin RNA to activate Pvalb transcript knockdown and subsequently downregulate PV. The downregulation was rapidly reversed after withdrawal of IPTG. In vitro and in vivo experiments revealed a decrease in PV expression of ≥50% in the presence of IPTG and full reversibility after IPTG removal. We foresee that the tightly regulated and reversible PV downregulation in mice in vivo will provide a new tool for the control of Pvalb transcript expression in a temporal manner. Because PV protein and PVALB transcript levels were found to be lower in the brain of patients with autism spectrum disorder and schizophrenia, the novel transgenic mouse line might serve as a model to investigate the putative role of PV in these neurodevelopmental disorders.
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Affiliation(s)
- Federica Filice
- Department of Neuroscience & Movements Science, Section of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Walter Blum
- Department of Neuroscience & Movements Science, Section of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Emanuel Lauber
- Department of Neuroscience & Movements Science, Section of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Beat Schwaller
- Department of Neuroscience & Movements Science, Section of Medicine, University of Fribourg, Fribourg, Switzerland
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2
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Chen T, Huang B, Shi X, Gao L, Huang C. Mutant UBQLN2 P497H in motor neurons leads to ALS-like phenotypes and defective autophagy in rats. Acta Neuropathol Commun 2018; 6:122. [PMID: 30409191 PMCID: PMC6225656 DOI: 10.1186/s40478-018-0627-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 10/30/2018] [Indexed: 12/12/2022] Open
Abstract
Mutations in ubiquilin2 (UBQLN2) have been linked to abnormal protein aggregation in amyotrophic lateral sclerosis (ALS). The mechanisms underlying UBQLN2-related neurodegenerative diseases remain unclear. Using a tetracycline-regulated gene expression system, the ALS-linked UBQLN2P497H mutant was selectively expressed in either the spinal motor neurons or astrocytes in rats. We found that selectively expressing mutant UBQLN2P497H in the spinal motor neurons caused several core features of ALS, including the progressive degeneration of motor neurons, the denervation atrophy of skeletal muscles, and the abnormal protein accumulation. Furthermore, mutant UBQLN2P497H accumulation was associated with an age-dependent decrease in several core autophagy-related proteins. ALS-like phenotypes were not observed when mutant UBQLN2P497H was overexpressed in the astrocytes, however, even though the expression of the mutant UBQLN2P497H protein was higher in these rats. Our results suggest that selectively expressing mutant UBQLN2P497H in motor neurons is sufficient to trigger the development of ALS in rats. Our results further indicate that the compromised autophagy-lysosomal pathway plays a critical role in the pathogenesis of UBQLN2-related neurodegenerative diseases.
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3
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The emerging framework of mammalian auditory hindbrain development. Cell Tissue Res 2015; 361:33-48. [DOI: 10.1007/s00441-014-2110-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 12/22/2014] [Indexed: 02/06/2023]
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4
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Rapid and reversible knockdown of endogenous proteins by peptide-directed lysosomal degradation. Nat Neurosci 2014; 17:471-80. [PMID: 24464042 PMCID: PMC3937121 DOI: 10.1038/nn.3637] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 12/16/2013] [Indexed: 12/13/2022]
Abstract
Rapid and reversible methods for altering the level of endogenous proteins are critically important for studying biological systems and developing therapeutics. Here, we describe a membrane permeable targeting peptide-based method that rapidly and reversibly knocks down endogenous proteins through chaperone-mediated autophagy in vitro and in vivo. We demonstrated the specificity, efficacy and generalizability of the method by showing efficient knockdown of various proteins including death associated protein kinase 1 (160kDa), scaffolding protein PSD-95 (95kDa) and α-synuclein (18kDa) with their respective targeting peptides in a dose-, time- and lysosomal activity-dependent manner in neuronal cultures. More significantly, we showed that when given systemically, the peptide system efficiently knocked down the targeted protein in the brain of intact rats. Our study provides a robust and convenient research tool to manipulate endogenous protein levels, and may also lead to the development of protein knockdown-based novel therapeutics for treating various human diseases.
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5
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Efficient ROSA26-Based Conditional and/or Inducible Transgenesis Using RMCE-Compatible F1 Hybrid Mouse Embryonic Stem Cells. Stem Cell Rev Rep 2013; 9:774-85. [DOI: 10.1007/s12015-013-9458-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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6
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Modeling the impact of mitochondrial DNA damage in forebrain neurons and beyond. Mech Ageing Dev 2011; 132:424-8. [PMID: 21354441 DOI: 10.1016/j.mad.2011.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 02/15/2011] [Accepted: 02/18/2011] [Indexed: 01/30/2023]
Abstract
We have generated an inducible transgenic mouse model, which expresses a mutated version of UNG1 (mutUNG1) that removes thymine, in addition to uracil from mitochondrial DNA. The abasic-sites (AP-sites) generated by removal of thymine or uracil are a threat to genomic integrity, and are particularly harmful in mitochondria due to inhibition of mitochondrial DNA polymerase. MutUNG1, accompanied by a luciferase reporter-gene, is controlled by the Tet-on system. Transgene expression is spatially regulated by the forebrain specific CaMKIIα-promoter, and temporally by the addition of doxycycline. Mice harboring this transgene develop compromised mitochondrial dynamics, neurodegeneration and impaired behavior.
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7
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Zhou H, Huang C, Chen H, Wang D, Landel CP, Xia PY, Bowser R, Liu YJ, Xia XG. Transgenic rat model of neurodegeneration caused by mutation in the TDP gene. PLoS Genet 2010; 6:e1000887. [PMID: 20361056 PMCID: PMC2845661 DOI: 10.1371/journal.pgen.1000887] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Accepted: 02/25/2010] [Indexed: 12/12/2022] Open
Abstract
TDP-43 proteinopathies have been observed in a wide range of neurodegenerative diseases. Mutations in the gene encoding TDP-43 (i.e., TDP) have been identified in amyotrophic lateral sclerosis (ALS) and in frontotemporal lobe degeneration associated with motor neuron disease. To study the consequences of TDP mutation in an intact system, we created transgenic rats expressing normal human TDP or a mutant form of human TDP with a M337V substitution. Overexpression of mutant, but not normal, TDP caused widespread neurodegeneration that predominantly affected the motor system. TDP mutation reproduced ALS phenotypes in transgenic rats, as seen by progressive degeneration of motor neurons and denervation atrophy of skeletal muscles. This robust rat model also recapitulated features of TDP-43 proteinopathies including the formation of TDP-43 inclusions, cytoplasmic localization of phosphorylated TDP-43, and fragmentation of TDP-43 protein. TDP transgenic rats will be useful for deciphering the mechanisms underlying TDP-43–related neurodegenerative diseases. Amyotrophic lateral sclerosis, a condition also known as Lou Gehrig's disease, is characterized by progressive degeneration of motor neurons, denervation atrophy of skeletal muscles, and eventual paralysis of affected limbs. The signature pathology of Lou Gehrig's disease is the formation of intracellular inclusions containing phosphorylated TDP-43 protein. Most cases of Lou Gehrig's disease do not have a clear cause, while only about 10% of the cases are caused by mutation of individual genes. Here, we describe a novel rat model that expresses a mutated form of the human gene encoding TDP-43 and manifests the phenotypes and pathological features observed in patients with Lou Gehrig's disease. Laboratory rats are the preferred animals for pharmacological studies. Therefore, this new rat model will be useful not only for mechanistic study of Lou Gehrig's disease, but also for the development of therapies for this devastating disease.
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Affiliation(s)
- Hongxia Zhou
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (HZ); (XGX)
| | - Cao Huang
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Han Chen
- Center for Biotechnology, University of Nebraska–Lincoln, Lincoln, Nebraska, United States of America
| | - Dian Wang
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Carlisle P. Landel
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Pedro Yuxing Xia
- Lower Merion High School, Ardmore, Pennsylvania, United States of America
| | - Robert Bowser
- Department of Pathology, Center of ALS Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Yong-Jian Liu
- Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Xu Gang Xia
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (HZ); (XGX)
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8
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Gama Sosa MA, De Gasperi R, Elder GA. Animal transgenesis: an overview. Brain Struct Funct 2009; 214:91-109. [PMID: 19937345 DOI: 10.1007/s00429-009-0230-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2009] [Accepted: 11/06/2009] [Indexed: 10/20/2022]
Abstract
Transgenic animals are extensively used to study in vivo gene function as well as to model human diseases. The technology for producing transgenic animals exists for a variety of vertebrate and invertebrate species. The mouse is the most utilized organism for research in neurodegenerative diseases. The most commonly used techniques for producing transgenic mice involves either the pronuclear injection of transgenes into fertilized oocytes or embryonic stem cell-mediated gene targeting. Embryonic stem cell technology has been most often used to produce null mutants (gene knockouts) but may also be used to introduce subtle genetic modifications down to the level of making single nucleotide changes in endogenous mouse genes. Methods are also available for inducing conditional gene knockouts as well as inducible control of transgene expression. Here, we review the main strategies for introducing genetic modifications into the mouse, as well as in other vertebrate and invertebrate species. We also review a number of recent methodologies for the production of transgenic animals including retrovirus-mediated gene transfer, RNAi-mediated gene knockdown and somatic cell mutagenesis combined with nuclear transfer, methods that may be more broadly applicable to species where both pronuclear injection and ES cell technology have proven less practical.
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Affiliation(s)
- Miguel A Gama Sosa
- Department of Psychiatry, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY, 10029, USA.
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9
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Emelyanov A, Parinov S. Mifepristone-inducible LexPR system to drive and control gene expression in transgenic zebrafish. Dev Biol 2008; 320:113-21. [PMID: 18544450 DOI: 10.1016/j.ydbio.2008.04.042] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 04/24/2008] [Accepted: 04/25/2008] [Indexed: 11/16/2022]
Abstract
Effective transgenesis methods have been successfully employed in many organisms including zebrafish. However, accurate spatiotemporal control of transgene expression is still difficult to achieve. Here we describe a system for chemical-inducible gene expression and demonstrate its feasibility for generating transgenic driver lines in zebrafish. The key element of this system is a hybrid transcription factor engineered by fusion of the DNA-binding domain of the bacterial LexA repressor, a truncated ligand-binding domain of the human progesterone receptor, and the activation domain of the human NF-kappaB/p65 protein. This hybrid transcription factor (LexPR transactivator) binds to the synthetic steroid, mifepristone (RU-486), and functions in a ligand-dependent manner to induce expression of the gene(s) placed under the control of a synthetic operator-promoter sequence that harbors LexA binding sites. Transgene expression is strictly controlled and can be induced at any stage of the life cycle through administration of mifepristone in the water. To demonstrate the utility of this system, we generated stable transgenic lines which allow inducible tissue-specific expression of activated K-ras(V12). Combined with the Ac/Ds-mediated transgenesis, the LexPR expression system has many potential applications in the fields of genetics and biotechnology.
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Affiliation(s)
- Alexander Emelyanov
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604, Singapore
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10
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Xie J, Nair A, Hermiston TW. A comparative study examining the cytotoxicity of inducible gene expression system ligands in different cell types. Toxicol In Vitro 2008; 22:261-6. [DOI: 10.1016/j.tiv.2007.08.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2007] [Revised: 08/14/2007] [Accepted: 08/30/2007] [Indexed: 11/26/2022]
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11
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Stark KL, Gross C, Richardson-Jones J, Zhuang X, Hen R. A novel conditional knockout strategy applied to serotonin receptors. Handb Exp Pharmacol 2007:347-63. [PMID: 17203662 DOI: 10.1007/978-3-540-35109-2_14] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Here we demonstrate the feasibility of a doubly regulatable transgenic mouse design that allows for gene manipulation by both Cre-recombinase and the tetracycline inducible system. Using a knock-in strategy to insert both elements of the tetracycline inducible system and a neomycin (neo) cassette flanked by loxP sequences (floxed) into the wild-type locus, we generated mice that express the 5-HT(1B) receptor in a conditional manner. In the presence of a floxed neo-cassette, receptor expression was silenced. Removal of this cassette by Cre-mediated recombination led to 5-HT(1B) receptor expression, which was highly regulatable when doxycycline, a derivative of tetracycline, was administered to the mice. This system allowed for a determination of an in vivo time course of receptor half-life and recovery. Physiological studies also demonstrated that rescued 5-HT(1B) receptors were functional, and that this functionality was reversible upon treatment with doxycycline. Crossing mice where the 5-HT(1B), or the 5-HT(1A), receptors were silenced by the neo-cassette, with mice expressing either Cre-recombinase or the tetracycline transactivator (tTA) under the control of tissue-specific promoters, led to tissue-specific re-expression of these receptors. Our studies thus demonstrate the potential of this strategy for achieving both a classic knockout, as well as subsequent tissue-specific and/or inducible knockouts.
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Affiliation(s)
- K L Stark
- Center for Neurobiology and Behavior, Columbia University, P.I. Annex, Room 729A, 722 West 168th Street, New York, NY 10032, USA
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12
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Xia XG, Zhou H, Xu Z. Transgenic RNAi: Accelerating and expanding reverse genetics in mammals. Transgenic Res 2007; 15:271-5. [PMID: 16779643 DOI: 10.1007/s11248-006-0023-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Accepted: 04/10/2006] [Indexed: 11/27/2022]
Abstract
Reverse genetics in mammals has relied on gene targeting strategies and has mostly been limited to the mouse. Gene targeting through homologous recombination in mouse ES cells has drawbacks which include time, expense and complexity. Recently, a new approach has been developed based on RNA-interference (RNAi) which is simpler, faster, less expensive, and should be applicable to mammalian species other than mouse. The advent of RNAi is poised to accelerate the pace at which reverse genetics can be applied to study gene function in mammals.
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Affiliation(s)
- Xu-Gang Xia
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
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13
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Andreadis ST. Gene-modified tissue-engineered skin: the next generation of skin substitutes. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2006; 103:241-74. [PMID: 17195466 DOI: 10.1007/10_023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Tissue engineering combines the principles of cell biology, engineering and materials science to develop three-dimensional tissues to replace or restore tissue function. Tissue engineered skin is one of most advanced tissue constructs, yet it lacks several important functions including those provided by hair follicles, sebaceous glands, sweat glands and dendritic cells. Although the complexity of skin may be difficult to recapitulate entirely, new or improved functions can be provided by genetic modification of the cells that make up the tissues. Gene therapy can also be used in wound healing to promote tissue regeneration or prevent healing abnormalities such as formation of scars and keloids. Finally, gene-enhanced skin substitutes have great potential as cell-based devices to deliver therapeutics locally or systemically. Although significant progress has been made in the development of gene transfer technologies, several challenges have to be met before clinical application of genetically modified skin tissue. Engineering challenges include methods for improved efficiency and targeted gene delivery; efficient gene transfer to the stem cells that constantly regenerate the dynamic epidermal tissue; and development of novel biomaterials for controlled gene delivery. In addition, advances in regulatable vectors to achieve spatially and temporally controlled gene expression by physiological or exogenous signals may facilitate pharmacological administration of therapeutics through genetically engineered skin. Gene modified skin substitutes are also employed as biological models to understand tissue development or disease progression in a realistic three-dimensional context. In summary, gene therapy has the potential to generate the next generation of skin substitutes with enhanced capacity for treatment of burns, chronic wounds and even systemic diseases.
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Affiliation(s)
- Stelios T Andreadis
- Bioengineering Laboratory, Department of Chemical & Biological Engineering, University at Buffalo, The State University of New York (SUNY), Amherst, NY 14260, USA.
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Indukuri H, Castro SM, Liao SM, Feeney LA, Dorsch M, Coyle AJ, Garofalo RP, Brasier AR, Casola A. Ikkepsilon regulates viral-induced interferon regulatory factor-3 activation via a redox-sensitive pathway. Virology 2006; 353:155-65. [PMID: 16806387 DOI: 10.1016/j.virol.2006.05.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Revised: 04/11/2006] [Accepted: 05/17/2006] [Indexed: 12/22/2022]
Abstract
Respiratory syncytial virus (RSV)-induced chemokine gene expression occurs through the activation of a subset of transcription factors, including Interferon Regulatory Factor (IRF)-3. In this study, we have investigated the signaling pathway leading to RSV-induced IRF-3 activation and whether it is mediated by intracellular reactive oxygen species (ROS) generation. Our results show that RSV infection induces expression and catalytic activity of IKKepsilon, a noncanonical IKK-like kinase. Expression of a kinase-inactive IKKepsilon blocks RSV-induced IRF-3 serine phosphorylation, nuclear translocation and DNA-binding, leading to inhibition of RANTES gene transcription, mRNA expression and protein synthesis. Treatment of alveolar epithelial cells with antioxidants or with NAD(P)H oxidase inhibitors abrogates RSV-induced chemokine secretion, IRF-3 phosphorylation and IKKepsilon induction, indicating that ROS generation plays a fundamental role in the signaling pathway leading to IRF-3 activation, therefore, identifying a novel molecular target for the development of strategies aimed to modify the inflammatory response associated with RSV infection of the lung.
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Affiliation(s)
- Hemalatha Indukuri
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555-0366, USA
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Zu T, Duvick LA, Kaytor MD, Berlinger MS, Zoghbi HY, Clark HB, Orr HT. Recovery from polyglutamine-induced neurodegeneration in conditional SCA1 transgenic mice. J Neurosci 2005; 24:8853-61. [PMID: 15470152 PMCID: PMC6729947 DOI: 10.1523/jneurosci.2978-04.2004] [Citation(s) in RCA: 229] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant, polyglutamine-induced neurodegenerative disorder that results in loss of motor coordination caused primarily by a disruption of cerebellar Purkinje cell function. In this study, we developed a conditional SCA1 mouse model to examine whether stopping expression of mutant ataxin-1 alters the disease phenotype. After cessation of SCA1[82Q] transgene expression, mutant ataxin-1, including that in nuclear inclusions, was cleared rapidly from Purkinje cells. At an early stage of disease, Purkinje cell pathology and motor dysfunction were completely reversible. After halting SCA1 expression at later stages of disease, only a partial recovery was seen. Interestingly, restoration of the ability to perform a complex motor task, the accelerating Rotarod, correlated with localization of mGluR1alpha to the Purkinje cell-parallel fiber synapse. These results show that the progression of SCA1 pathogenesis is dependent on the continuous expression of mutant ataxin-1. Of note, even at a late stage of disease, Purkinje cells retain at least some ability to repair the damage caused by mutant ataxin-1.
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Affiliation(s)
- Tao Zu
- Institute of Human Genetics, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Whittlesey KJ, Shea LD. Delivery systems for small molecule drugs, proteins, and DNA: the neuroscience/biomaterial interface. Exp Neurol 2005; 190:1-16. [PMID: 15473976 DOI: 10.1016/j.expneurol.2004.06.020] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 04/30/2004] [Accepted: 06/18/2004] [Indexed: 11/18/2022]
Abstract
Manipulation of cellular processes in vivo by the delivery of drugs, proteins or DNA is of paramount importance to neuroscience research. Methods for the presentation of these molecules vary widely, including direct injection (either systemic or stereotactic), osmotic pump-mediated chronic delivery, or even implantation of cells engineered to indefinitely secrete a factor of interest. Biomaterial-based delivery systems represent an alternative to more traditional approaches, with the possibility of increased efficacy. Drug-releasing biomaterials, either as injectable microspheres or as three-dimensional implants, can deliver a molecule of interest (including small molecule drugs, biologically active proteins, or DNA) over a more prolonged period of time than by standard bolus injection, avoiding the need for repeated administration. Furthermore, sustained-release systems can maintain therapeutic concentrations at a target site, thus reducing the chance for toxicity. This review summarizes applications of polymer-based delivery of small molecule drugs, proteins, and DNA specifically relevant to neuroscience research. We detail the fabrication procedures for the polymeric systems and their utility in various experimental models. The biomaterial field offers unique experimental tools with downstream clinical application for the study and treatment of neurologic disease.
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Affiliation(s)
- Kevin J Whittlesey
- Interdepartmental Biological Sciences Program, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
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17
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Heine HL, Leong HS, Rossi FMV, McManus BM, Podor TJ. Strategies of Conditional Gene Expression in Myocardium. MOLECULAR CARDIOLOGY 2005; 112:109-54. [PMID: 16010014 DOI: 10.1007/978-1-59259-879-3_8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The use of specialized reporter genes to monitor real-time, tissue-specific transgene expression in animal models offers an opportunity to circumvent current limitations associated with the establishment of transgenic mouse models. The Cre-loxP and the tetracycline (Tet)-inducible systems are useful methods of conditional gene expression that allow spatial (cell-type-specific) and temporal (inducer-dependent) control. Most often, the alpha-myosin heavy chain (alpha-MHC) promoter is used in these inducible systems to restrict expression of reporter genes and transgenes to the myocardium. An overview of each inducible system is described, along with suggested reporter genes for real-time, noninvasive imaging in the myocardium. Effective gene delivery of the inducible gene expression system is carried out by lentiviral vectors, which offer high transduction efficiency, long-term transgene expression, and low immunogenicity. This chapter outlines the packaging of myocardium-specific inducible expression systems into lentiviral vectors, in which a transgene and a reporter gene are transduced into cardiomyocytes. In doing so, transgene and reporter expression can be monitored/tracked with bioluminescence imaging (BLI) and positron emission tomography (PET).
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Affiliation(s)
- Heather L Heine
- The James Hogg iCAPTURE Center for Cardiovascular and Pulmonary Research/MRL, University of British Columbia, St. Paul's Hospital, Vancouver, Canada
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18
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Michalon A, Koshibu K, Baumgärtel K, Spirig DH, Mansuy IM. Inducible and neuron-specific gene expression in the adult mouse brain with the rtTA2S-M2 system. Genesis 2005; 43:205-12. [PMID: 16342161 DOI: 10.1002/gene.20175] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To achieve inducible and reversible gene expression in the adult mouse brain, we exploited an improved version of the tetracycline-controlled transactivator-based system (rtTA2(S)-M2, rtTA2 hereafter) and combined it with the forebrain-specific CaMKIIalpha promoter. Several independent lines of transgenic mice carrying the CaMKIIalpha promoter-rtTA2 gene were generated and examined for anatomical profile, doxycycline (dox)-dependence, time course, and reversibility of gene expression using several lacZ reporter lines. In two independent rtTA2-expressing lines, dox-treatment in the diet induced lacZ reporter expression in neurons of several forebrain structures including cortex, striatum, hippocampus, amygdala, and olfactory bulb. Gene expression was dose-dependent and was fully reversible. Further, a similar pattern of expression was obtained in three independent reporter lines, indicating the consistency of gene expression. Transgene expression could also be activated in the developing brain (P0) by dox-treatment of gestating females. These new rtTA2-expressing mice allowing inducible and reversible gene expression in the adult or developing forebrain represent useful models for future genetic studies of brain functions.
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Affiliation(s)
- Aubin Michalon
- Brain Research Institute, Medical Faculty of University of Zürich, and Department of Biology of the Swiss Federal Institute of Technology, Switzerland
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Giménez E, Lavado A, Giraldo P, Cozar P, Jeffery G, Montoliu L. A Transgenic Mouse Model with Inducible Tyrosinase Gene Expression Using the Tetracycline (Tet-on) System Allows Regulated Rescue of Abnormal Chiasmatic Projections Found in Albinism. ACTA ACUST UNITED AC 2004; 17:363-70. [PMID: 15250938 DOI: 10.1111/j.1600-0749.2004.00158.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Congenital defects in retinal pigmentation, as in oculocutaneous albinism Type I (OCA1), where tyrosinase is defective, result in visual abnormalities affecting the retina and pathways into the brain. Transgenic animals expressing a functional tyrosinase gene on an albino genetic background display a correction of all these abnormalities, implicating a functional role for tyrosinase in normal retinal development. To address the function of tyrosinase in the development of the mammalian visual system, we have generated a transgenic mouse model with inducible expression of the tyrosinase gene using the tetracycline (TET-ON) system. We have produced two types of transgenic mice: first, mice expressing the transactivator rtTA chimeric protein under the control of mouse tyrosinase promoter and its locus control region (LCR), and; second, transgenic mice expressing a mouse tyrosinase cDNA construct driven by a minimal promoter inducible by rtTA in the presence of doxycycline. Inducible experiments have been carried out with selected double transgenic mouse lines. Tyrosinase expression has been induced from early embryo development and its impact assessed with histological and biochemical methods in heterozygous and homozygous double transgenic individuals. We have found an increase of tyrosinase activity in the eyes of induced animals, compared with littermate controls. However, there was significant variability in the activation of this gene, as reported in analogous experiments. In spite of this, we could observe corrected uncrossed chiasmatic pathways, decreased in albinism, in animals induced from their first gestational week. These mice could be instrumental in revealing the role of tyrosinase in mammalian visual development.
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Affiliation(s)
- Estela Giménez
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus de Cantoblanco, 28049 Madrid, Spain
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Mitta B, Weber CC, Rimann M, Fussenegger M. Design and in vivo characterization of self-inactivating human and non-human lentiviral expression vectors engineered for streptogramin-adjustable transgene expression. Nucleic Acids Res 2004; 32:e106. [PMID: 15258250 PMCID: PMC484201 DOI: 10.1093/nar/gnh104] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Adjustable transgene expression is considered key for next-generation molecular interventions in gene therapy scenarios, therapeutic reprogramming of clinical cell phenotypes for tissue engineering and sophisticated gene-function analyses in the post-genomic era. We have designed a portfolio of latest generation self-inactivating human (HIV-derived) and non-human (EIAV-based) lentiviral expression vectors engineered for streptogramin-adjustable expression of reporter (AmyS(DeltaS), EYFP, SAMY, SEAP), differentiation-modulating (human C/EBP-alpha) and therapeutic (human VEGF) transgenes in a variety of rodent (CHO-K1, C2C12) and human cell lines (HT-1080, K-562), human and mouse primary cells (NHDF, PBMC, CD4+) as well as chicken embryos. Lentiviral design concepts include (i) binary systems harboring constitutive streptogramin-dependent transactivator (PIT) and PIT-responsive transgene expression units on separate lentivectors; (ii) streptogramin-responsive promoters (P(PIR8)) placed 5' of desired transgenes; (iii) within modified enhancer-free 3'-long terminal repeats; and (iv) bidirectional autoregulated configurations providing streptogramin-responsive transgene expression in a lentiviral one-vector format. Rigorous quantitative analysis revealed HIV-based direct P(PIR)-transgene configurations to provide optimal regulation performance for (i) adjustable expression of intracellular and secreted product proteins, (ii) regulated differential differentiation of muscle precursor cell lines into adipocytes or osteoblasts and (iii) conditional vascularization fine-tuning in chicken embryos. Similar performance could be achieved by engineering streptogramin-responsive transgene expression into an autoregulated one-vector format. Powerful transduction systems equipped with adjustable transcription modulation options are expected to greatly advance sophisticated molecular interventions in clinically and/or biotechnologically relevant primary cells and cell lines.
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Affiliation(s)
- Barbara Mitta
- Institute of Biotechnology, Swiss Federal Institute of Technology, ETH Hoenggerberg, HPT D74, CH-8093 Zurich, Switzerland
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Hatta T, Matsumoto A, Otani H. Application of the mouse exo utero development system in the study of developmental biology and teratology. Congenit Anom (Kyoto) 2004; 44:2-8. [PMID: 15008894 DOI: 10.1111/j.1741-4520.2003.00002.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mouse exo utero development system is useful for analyzing the roles of molecules or interactions between tissues in the histogenesis of organs after the mid-gestational period. In the article presented here, we review the mouse exo utero development system and its specific modifications depending on different purposes as well as its advantages over and limitations compared to other systems in the study of developmental biology and teratology.
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Affiliation(s)
- Toshihisa Hatta
- Department of Anatomy, Faculty of Medicine, Shimane University, Izumo, Japan.
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22
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Abstract
Gene regulation by tetracyclines has become a widely-used tool to study gene functions in pro- and eukaryotes. This regulatory system originates from Gram-negative bacteria, in which it fine-tunes expression of a tetracycline-specific export protein mediating resistance against this antibiotic. This review attempts to describe briefly the selective pressures governing the evolution of tetracycline regulation, which have led to the unique regulatory properties underlying its success in manifold applications. After discussing the basic mechanisms we will present the large variety of designed alterations of activities which have contributed to the still growing tool-box of components available for adjusting the regulatory properties to study gene functions in different organisms or tissues. Finally, we provide an overview of the various experimental setups available for pro- and eukaryotes, and touch upon some highlights discovered by the use of tetracycline-dependent gene regulation.
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Affiliation(s)
- Christian Berens
- Lehrstuhl für Mikrobiologie, Friedrich-Alexander Universität Erlangen-Nürnberg, Staudtstr. 5, D-91058, Erlangen, Germany
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Berens C, Hillen W. Gene regulation by tetracyclines. Constraints of resistance regulation in bacteria shape TetR for application in eukaryotes. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:3109-21. [PMID: 12869186 DOI: 10.1046/j.1432-1033.2003.03694.x] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Tet repressor protein (TetR) regulates transcription of a family of tetracycline (tc) resistance determinants in Gram-negative bacteria. The resistance protein TetA, a membrane-spanning H+-[tc.M]+ antiporter, must be sensitively regulated because its expression is harmful in the absence of tc, yet it has to be expressed before the drugs' concentration reaches cytoplasmic levels inhibitory for protein synthesis. Consequently, TetR shows highly specific tetO binding to reduce basal expression and high affinity to tc to ensure sensitive induction. Tc can cross biological membranes by diffusion enabling this inducer to penetrate the majority of cells. These regulatory and pharmacological properties are the basis for application of TetR to selectively control the expression of single genes in lower and higher eukaryotes. TetR can be used for that purpose in some organisms without further modifications. In mammals and in a large variety of other organisms, however, eukaryotic transcriptional activator or repressor domains are fused to TetR to turn it into an efficient regulator. Mechanistic understanding and the ability to engineer and screen for mutants with specific properties allow tailoring of the DNA recognition specificity, the response to inducer tc and the dimerization specificity of TetR-based eukaryotic regulators. This review provides an overview of the TetR properties as they evolved in bacteria, the functional modifications necessary to transform it into a convenient, specific and efficient regulator for use in eukaryotes and how the interplay between structure--function studies in bacteria and specific requirements of particular applications in eukaryotes have made it a versatile and highly adaptable regulatory system.
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Affiliation(s)
- Christian Berens
- Lehrstuhl für Mikrobiologie, Institut für Mikrobiologie, Biochemie und Genetik, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany
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Wiechert S, El-Armouche A, Rau T, Zimmermann WH, Eschenhagen T. 24-h Langendorff-perfused neonatal rat heart used to study the impact of adenoviral gene transfer. Am J Physiol Heart Circ Physiol 2003; 285:H907-14. [PMID: 12663262 DOI: 10.1152/ajpheart.00856.2002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The human genome project has increased the demand for simple experimental systems that allow the impact of gene manipulations to be studied under controlled ex vivo conditions. We hypothesized that, in contrast to adult hearts, neonatal hearts allow long-term perfusion and efficient gene transfer ex vivo. A Langendorff perfusion system was modified to allow perfusion for >24 h with particular emphasis on uncompromised contractile activity, sterility, online measurement of force of contraction, inotropic response to beta-adrenergic stimulation, and efficient gene transfer. The hearts were perfused with serum-free medium (DMEM + medium 199, 4 + 1) supplemented with hydrocortisone, triiodothyronine, ascorbic acid, insulin, pyruvate, l-carnitine, creatine, taurine, l-glutamine, mannitol, and antibiotics recirculating (500 ml/2 hearts) at 1 ml/min. Hearts from 2 day-old rats beat constantly at 135-155 beats/min and developed active force of 1-2 mN. During 24 h of perfusion, twitch tension increased to approximately 165% of initial values (P < 0.05), whereas the inotropic response to isoprenaline remained constant. A decrease in total protein content of 10% and histological examination indicated moderate edema, but actin and calsequestrin concentration remained unchanged and perfusion pressure remained constant at 7-11 mmHg. Perfusion with a LacZ-encoding adenovirus at 3 x 108 active virus particles yielded homogeneous transfection of approximately 80% throughout the heart and did not affect heart rate, force of contraction, or response to isoprenaline compared with uninfected controls (n = 7 each). Taken together, the 24-h Langendorff-perfused neonatal rat heart is a relatively simple, inexpensive, and robust new heart model that appears feasible as a test bed for functional genomics.
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Affiliation(s)
- S Wiechert
- Institute of Experimental and Clinical Pharmacology, University Erlangen-Nürnberg, 91054 Erlangen, Germany
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25
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Chiocca EA. Gene therapy: a primer for neurosurgeons. Neurosurgery 2003; 53:364-73; discussion 373. [PMID: 12925253 DOI: 10.1227/01.neu.0000073532.05714.2b] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2003] [Accepted: 04/11/2003] [Indexed: 11/19/2022] Open
Abstract
Gene therapy involves the transfer of genes into cells with therapeutic intent. Although several methods can accomplish this, vectors based on viruses still provide the most efficient approach. For neurosurgical purposes, preclinical and clinical applications in the areas of glioma therapy, spinal neurosurgery, and neuroprotection for treatment of Parkinson's disease and cerebral ischemia are reviewed. In general, therapies applied in the neurosurgical realm have proven relatively safe, despite occasional, well-publicized cases of morbidity and death in non-neurosurgical trials. However, continued clinical and preclinical research in this area is critical, to fully elucidate potential toxicities and to generate truly effective treatments that can be applied in neurological diseases.
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Affiliation(s)
- E Antonio Chiocca
- Molecular Neuro-oncology Laboratory, Neurosurgery Service, Massachusetts General Hospital, Brain Tumor Center, Boston, Massachusetts 02114, USA.
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26
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Abstract
Tolerance is an important component of opiate addiction, but the molecular basis for this phenomenon remains obscure. Here, we report that mice lacking neurotrophin-4 (NT4) display substantially reduced tolerance to morphine compared to wild-type. However, there were no deficits in sensitization and withdrawal, other behaviors relevant to drug addiction. Since NT4 knockout mice also show abnormalities in long-term but not short-term memory, our findings suggest common molecular pathways for some of the enduring changes of drug addiction and memory consolidation.
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Affiliation(s)
- Desmond J Smith
- Department of Molecular and Medical Pharmacology, UCLA School of Medicine, Los Angeles, CA 90095, USA
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27
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Abstract
Manipulation of the mouse genome allows emulation of the genetic defects that give rise to human cancers and evaluation of the cooperating nature of different mutations in the transformation of distinct cell types. Here we review the generation of mice with specific missense mutations in p53 (TP53) and disruption of the p53 pathway by deletion of p53 inhibitors. Missense mutations in the DNA binding domain result in viable mice with gain-of-function and dominant negative phenotypes. Loss of either of the p53 inhibitors mdm2 or mdm4 gives rise to a p53-dependent embryonic lethal phenotype. A cell can thus tolerate the absence of p53 function but not excess p53 function, a characteristic that is being exploited in the treatment of human cancers.
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Affiliation(s)
- John M Parant
- Department of Molecular Genetics, Section of Cancer Genetics, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030-4095, USA
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Grill MA, Bales MA, Fought AN, Rosburg KC, Munger SJ, Antin PB. Tetracycline-inducible system for regulation of skeletal muscle-specific gene expression in transgenic mice. Transgenic Res 2003; 12:33-43. [PMID: 12650523 DOI: 10.1023/a:1022119005836] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Tightly regulated control of over-expression is often necessary to study one aspect or time point of gene function and, in transgenesis, may help to avoid lethal effects and complications caused by ubiquitous over-expression. We have utilized the benefits of an optimized tet-on system and a modified muscle creatine kinase (MCK) promoter to generate a skeletal muscle-specific, doxycycline (Dox) controlled over-expression system in transgenic mice. A DNA construct was generated in which the codon optimized reverse tetracycline transactivator (rtTA) was placed under control of a skeletal muscle-specific version of the mouse MCK promoter. Transgenic mice containing this construct expressed rtTA almost exclusively in skeletal muscles. These mice were crossed to a second transgenic line containing a bi-directional promoter centered on a tet responder element driving both a luciferase reporter gene and a tagged gene of interest; in this case the calpain inhibitor calpastatin. Compound hemizygous mice showed high level, Dox dependent muscle-specific luciferase activity often exceeding 10,000-fold over non-muscle tissues of the same mouse. Western and immunocytochemical analysis demonstrated similar Dox dependent muscle-specific induction of the tagged calpastatin protein. These findings demonstrate the effectiveness and flexibility of the tet-on system to provide a tightly regulated over-expression system in adult skeletal muscle. The MCKrtTA transgenic lines can be combined with other transgenic responder lines for skeletal muscle-specific over-expression of any target gene of interest.
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Affiliation(s)
- Mischala A Grill
- Department of Cell Biology and Anatomy, PO Box 245044, University of Arizona, Tucson, Arizona, 85724, USA
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Bockamp E, Maringer M, Spangenberg C, Fees S, Fraser S, Eshkind L, Oesch F, Zabel B. Of mice and models: improved animal models for biomedical research. Physiol Genomics 2002; 11:115-32. [PMID: 12464688 DOI: 10.1152/physiolgenomics.00067.2002] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The ability to engineer the mouse genome has profoundly transformed biomedical research. During the last decade, conventional transgenic and gene knockout technologies have become invaluable experimental tools for modeling genetic disorders, assigning functions to genes, evaluating drugs and toxins, and by and large helping to answer fundamental questions in basic and applied research. In addition, the growing demand for more sophisticated murine models has also become increasingly evident. Good state-of-principle knowledge about the enormous potential of second-generation conditional mouse technology will be beneficial for any researcher interested in using these experimental tools. In this review we will focus on practice, pivotal principles, and progress in the rapidly expanding area of conditional mouse technology. The review will also present an internet compilation of available tetracycline-inducible mouse models as tools for biomedical research (http://www.zmg.uni-mainz.de/tetmouse/).
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Affiliation(s)
- Ernesto Bockamp
- Laboratory of Molecular Mouse Genetics, Institute of Toxicology, Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany.
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Régulier E, Pereira de Almeida L, Sommer B, Aebischer P, Déglon N. Dose-dependent neuroprotective effect of ciliary neurotrophic factor delivered via tetracycline-regulated lentiviral vectors in the quinolinic acid rat model of Huntington's disease. Hum Gene Ther 2002; 13:1981-90. [PMID: 12427308 DOI: 10.1089/10430340260355383] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The ability to regulate gene expression constitutes a prerequisite for the development of gene therapy strategies aimed at the treatment of neurologic disorders. In the present work, we used tetracycline (Tet)-regulated lentiviral vectors to investigate the dose-dependent neuroprotective effect of human ciliary neurotrophic factor (CNTF) in the quinolinic acid (QA) model of Huntington's disease (HD). The Tet system was split in two lentiviruses, the first one containing the CNTF or green fluorescent protein (GFP) cDNAs under the control of the Tet-response element (TRE) and a second vector encoding the transactivator (tTA). Preliminary coinfection study demonstrated that 63.8% +/- 2.0% of infected cells contain at least two viral copies. Adult rats were then injected with CNTF- and GFP-expressing viral vectors followed 3 weeks later by an intrastriatal administration of QA. A significant reduction of apomorphine-induced rotations was observed in the CNTF-on group. In contrast, GFP-treated animals or CNTF-off rats displayed an ipsilateral turning behavior in response to apomorphine. A selective sparing of DARPP-32-, choline acetyltransferase (ChAT)-, and NADPH-d-positive neurons was observed in the striatum of CNTF-on rats compared to GFP animals and CNTF-off group. Enzyme-linked immunosorbent assay (ELISA) performed on striatal samples of rats sacrificed at the same time point indicated that this neuroprotective effect was associated with the production of 15.5 +/- 4.7 ng CNTF per milligram of protein whereas the residual CNTF expression in the off state (0.54 +/- 0.02 ng/mg of protein) was not sufficient to protect against QA toxicity. These results establish the proof of principle of neurotrophic factor dosing for neurodegenerative diseases and demonstrate the feasibility of lentiviral-mediated tetracycline-regulated gene transfer in the brain.
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Affiliation(s)
- E Régulier
- Institute of Neurosciences, Swiss Federal Institute of Technology Lausanne, 1015 Lausanne, Switzerland
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