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Lu P, Freria CM, Graham L, Tran AN, Villarta A, Yassin D, Huie JR, Ferguson AR, Tuszynski MH. Rehabilitation combined with neural progenitor cell grafts enables functional recovery in chronic spinal cord injury. JCI Insight 2022; 7:e158000. [PMID: 35993363 PMCID: PMC9462483 DOI: 10.1172/jci.insight.158000] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 07/14/2022] [Indexed: 02/05/2023] Open
Abstract
We reported previously that neural progenitor cell (NPC) grafts form neural relays across sites of subacute spinal cord injury (SCI) and support functional recovery. Here, we examine whether NPC grafts after chronic delays also support recovery and whether intensive rehabilitation further enhances recovery. One month after severe bilateral cervical contusion, rats received daily intensive rehabilitation, NPC grafts, or both rehabilitation and grafts. Notably, only the combination of rehabilitation and grafting significantly improved functional recovery. Moreover, improved functional outcomes were associated with a rehabilitation-induced increase in host corticospinal axon regeneration into grafts. These findings identify a critical and synergistic role of rehabilitation and neural stem cell therapy in driving neural plasticity to support functional recovery after chronic and severe SCI.
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Affiliation(s)
- Paul Lu
- Veterans Administration Medical Center, San Diego, California, USA
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - Camila M. Freria
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - Lori Graham
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - Amanda N. Tran
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - Ashley Villarta
- Veterans Administration Medical Center, San Diego, California, USA
| | - Dena Yassin
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - J. Russell Huie
- Department of Neurological Surgery, University of California, San Francisco, California, USA
| | - Adam R. Ferguson
- Department of Neurological Surgery, University of California, San Francisco, California, USA
| | - Mark H. Tuszynski
- Veterans Administration Medical Center, San Diego, California, USA
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
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Börjesson V, Martinez-Monleon A, Fransson S, Kogner P, Johnsen JI, Milosevic J, López MD. TC-hunter: identification of the insertion site of a transgenic gene within the host genome. BMC Genomics 2022; 23:149. [PMID: 35184734 PMCID: PMC8859905 DOI: 10.1186/s12864-022-08376-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 02/08/2022] [Indexed: 11/10/2022] Open
Abstract
Background Transgenic animal models are crucial for the study of gene function and disease, and are widely utilized in basic biological research, agriculture and pharma industries. Since the current methods for generating transgenic animals result in the random integration of the transgene under study, the phenotype may be compromised due to disruption of known genes or regulatory regions. Unfortunately, most of the tools that predict transgene insertion sites from high-throughput data are not publicly available or not properly maintained. Results We implemented TC-hunter, Transgene-Construct hunter, an open tool that identifies transgene insertion sites and provides simple reports and visualization aids. It relies on common tools used in the analysis of high-throughput data and makes use of chimeric reads and discordant read pairs to identify and support the transgenic insertion site. To demonstrate its applicability, we applied TC-hunter to four transgenic mice samples harboring the human PPM1D gene, a model used in the study of malignant tumor development. We identified the transgenic insertion site in each sample and experimentally validated them with Touchdown-polymerase chain reaction followed by Sanger sequencing. Conclusions TC-hunter is an accessible bioinformatics tool that can automatically identify transgene insertion sites from DNA sequencing data with high sensitivity (98%) and precision (92.45%). TC-hunter is a valuable tool that can aid in evaluating any potential phenotypic complications due to the random integration of the transgene and can be accessed at https://github.com/bcfgothenburg/SSF. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08376-0.
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Human Somatostatin SST 4 Receptor Transgenic Mice: Construction and Brain Expression Pattern Characterization. Int J Mol Sci 2021; 22:ijms22073758. [PMID: 33916620 PMCID: PMC8038480 DOI: 10.3390/ijms22073758] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 12/13/2022] Open
Abstract
Somatostatin receptor subtype 4 (SST4) has been shown to mediate analgesic, antidepressant and anti-inflammatory functions without endocrine actions; therefore, it is proposed to be a novel target for drug development. To overcome the species differences of SST4 receptor expression and function between humans and mice, we generated an SST4 humanized mouse line to serve as a translational animal model for preclinical research. A transposon vector containing the hSSTR4 and reporter gene construct driven by the hSSTR4 regulatory elements were created. The vector was randomly inserted in Sstr4-deficient mice. hSSTR4 expression was detected by bioluminescent in vivo imaging of the luciferase reporter predominantly in the brain. RT-qPCR confirmed the expression of the human gene in the brain and various peripheral tissues consistent with the in vivo imaging. RNAscope in situ hybridization revealed the presence of hSSTR4 transcripts in glutamatergic excitatory neurons in the CA1 and CA2 regions of the hippocampus; in the GABAergic interneurons in the granular layer of the olfactory bulb and in both types of neurons in the primary somatosensory cortex, piriform cortex, prelimbic cortex and amygdala. This novel SST4 humanized mouse line might enable us to investigate the differences of human and mouse SST4 receptor expression and function and assess the effects of SST4 receptor agonist drug candidates.
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Lee J, Kim DH, Lee K. Current Approaches and Applications in Avian Genome Editing. Int J Mol Sci 2020; 21:ijms21113937. [PMID: 32486292 PMCID: PMC7312999 DOI: 10.3390/ijms21113937] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 01/02/2023] Open
Abstract
Advances in genome-editing technologies and sequencing of animal genomes enable researchers to generate genome-edited (GE) livestock as valuable animal models that benefit biological researches and biomedical and agricultural industries. As birds are an important species in biology and agriculture, their genome editing has gained significant interest and is mainly performed by using a primordial germ cell (PGC)-mediated method because pronuclear injection is not practical in the avian species. In this method, PGCs can be isolated, cultured, genetically edited in vitro, and injected into a recipient embryo to produce GE offspring. Recently, a couple of GE quail have been generated by using the newly developed adenovirus-mediated method. Without technically required in vitro procedures of the PGC-mediated method, direct injection of adenovirus into the avian blastoderm in the freshly laid eggs resulted in the production of germ-line chimera and GE offspring. As more approaches are available in avian genome editing, avian research in various fields will progress rapidly. In this review, we describe the development of avian genome editing and scientific and industrial applications of GE avian species.
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Affiliation(s)
- Joonbum Lee
- Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA; (J.L.); (D.-H.K.)
- The Ohio State University Interdisciplinary Human Nutrition Program, The Ohio State University, Columbus, OH 43210, USA
| | - Dong-Hwan Kim
- Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA; (J.L.); (D.-H.K.)
| | - Kichoon Lee
- Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA; (J.L.); (D.-H.K.)
- The Ohio State University Interdisciplinary Human Nutrition Program, The Ohio State University, Columbus, OH 43210, USA
- Correspondence: ; Tel.: +1-614-688-7963
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Lu P, Gomes-Leal W, Anil S, Dobkins G, Huie JR, Ferguson AR, Graham L, Tuszynski M. Origins of Neural Progenitor Cell-Derived Axons Projecting Caudally after Spinal Cord Injury. Stem Cell Reports 2019; 13:105-114. [PMID: 31204300 PMCID: PMC6626851 DOI: 10.1016/j.stemcr.2019.05.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 05/10/2019] [Accepted: 05/12/2019] [Indexed: 12/30/2022] Open
Abstract
Neural progenitor cells (NPCs) transplanted into sites of spinal cord injury (SCI) extend large numbers of axons into the caudal host spinal cord. We determined the precise locations of neurons in the graft that extend axons into the caudal host spinal cord using AAV9-Cre-initiated retrograde tracing into floxed-TdTomato-expressing NPC grafts. 7,640 ± 630 grafted neurons extended axons to a single caudal host spinal cord site located 2 mm beyond the lesion, 5 weeks post injury. While caudally projecting axons arose from neurons located in all regions of the graft, the majority of caudally projecting graft neurons (53%) were located within the caudal one-third of the graft. Numerous host corticospinal axons formed monosynaptic projections onto caudally projecting graft neurons; however, we find that the majority of host axonal neuronal projections formed by neural progenitor cell interneuronal "relays" across sites of SCI are likely polysynaptic in nature.
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Affiliation(s)
- Paul Lu
- Veterans Administration-San Diego Healthcare System, San Diego, CA 92161, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093-0626, USA.
| | - Walace Gomes-Leal
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093-0626, USA; Laboratory of Experimental Neuroprotection and Neuroregeneration, Institute of Biological Sciences, Federal University of Pará Belém, Brazil
| | - Selin Anil
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093-0626, USA; Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland
| | - Gabriel Dobkins
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093-0626, USA
| | - J Russell Huie
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Adam R Ferguson
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Lori Graham
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093-0626, USA
| | - Mark Tuszynski
- Veterans Administration-San Diego Healthcare System, San Diego, CA 92161, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093-0626, USA.
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Cai W, Xie S, Zhang J, Tang D, Tang Y. Immobilized-free miniaturized electrochemical sensing system for Pb2+ detection based on dual Pb2+-DNAzyme assistant feedback amplification strategy. Biosens Bioelectron 2018; 117:312-318. [DOI: 10.1016/j.bios.2018.06.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/31/2018] [Accepted: 06/07/2018] [Indexed: 01/25/2023]
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7
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Yum SY, Lee SJ, Park SG, Shin IG, Hahn SE, Choi WJ, Kim HS, Kim HJ, Bae SH, Lee JH, Moon JY, Lee WS, Lee JH, Lee CI, Kim SJ, Jang G. Long-term health and germline transmission in transgenic cattle following transposon-mediated gene transfer. BMC Genomics 2018; 19:387. [PMID: 29792157 PMCID: PMC5966871 DOI: 10.1186/s12864-018-4760-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 05/04/2018] [Indexed: 12/25/2022] Open
Abstract
Background Transposon-mediated, non-viral gene delivery is a powerful tool for generating stable cell lines and transgenic animals. However, as multi-copy insertion is the preferred integration pattern, there is the potential for uncontrolled changes in endogenous gene expression and detrimental effects in cells or animals. Our group has previously reported on the generation of several transgenic cattle by using microinjection of the Sleeping Beauty (SB) and PiggyBac (PB) transposons and seeks to explore the long-term effects of this technology on cattle. Results Transgenic cattle, one female (SNU-SB-1) and one male (SNU-PB-1), reached over 36 months of age with no significant health issues and normal blood parameters. The detection of transgene integration and fluorescent signal in oocytes and sperm suggested the capacity for germline transmission in both of the founder animals. After natural breeding, the founder transgenic cow delivered a male calf and secreted milk containing fluorescent transgenic proteins. The calf expressed green fluorescent protein in primary cells from ear skin, with no significant change in overall genomic stability and blood parameters. Three sites of transgene integration were identified by next-generation sequencing of the calf’s genome. Conclusions Overall, these data demonstrate that transposon-mediated transgenesis can be applied to cattle without being detrimental to their long-term genomic stability or general health. We further suggest that this technology may be usefully applied in other fields, such as the generation of transgenic animal models. Electronic supplementary material The online version of this article (10.1186/s12864-018-4760-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Soo-Young Yum
- Department of Theriogenology, College of Veterinary Medicine and the Research Institute of Veterinary Science, Seoul National University, #631 Building 85, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Song-Jeon Lee
- Embryo Research Center, Seoul Milk Coop, Gyeonggi-do, 12528, Republic of Korea
| | - Sin-Gi Park
- Bioinformatics Team, Theragen Etex Bio Institute, Advanced Institutes of Convergence Technology, Kwanggyo Technovalley, Suwon, 16229, Republic of Korea
| | - In-Gang Shin
- Bioinformatics Team, Theragen Etex Bio Institute, Advanced Institutes of Convergence Technology, Kwanggyo Technovalley, Suwon, 16229, Republic of Korea
| | - Sang-Eun Hahn
- Department of Theriogenology, College of Veterinary Medicine and the Research Institute of Veterinary Science, Seoul National University, #631 Building 85, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Woo-Jae Choi
- Department of Theriogenology, College of Veterinary Medicine and the Research Institute of Veterinary Science, Seoul National University, #631 Building 85, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Hee-Soo Kim
- Embryo Research Center, Seoul Milk Coop, Gyeonggi-do, 12528, Republic of Korea
| | - Hyeong-Jong Kim
- Embryo Research Center, Seoul Milk Coop, Gyeonggi-do, 12528, Republic of Korea
| | - Seong-Hun Bae
- Embryo Research Center, Seoul Milk Coop, Gyeonggi-do, 12528, Republic of Korea
| | - Je-Hyeong Lee
- Embryo Research Center, Seoul Milk Coop, Gyeonggi-do, 12528, Republic of Korea
| | - Joo-Yeong Moon
- Embryo Research Center, Seoul Milk Coop, Gyeonggi-do, 12528, Republic of Korea
| | - Woo-Sung Lee
- Embryo Research Center, Seoul Milk Coop, Gyeonggi-do, 12528, Republic of Korea
| | - Ji-Hyun Lee
- Department of Theriogenology, College of Veterinary Medicine and the Research Institute of Veterinary Science, Seoul National University, #631 Building 85, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Choong-Il Lee
- Department of Theriogenology, College of Veterinary Medicine and the Research Institute of Veterinary Science, Seoul National University, #631 Building 85, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Seong-Jin Kim
- Bioinformatics Team, Theragen Etex Bio Institute, Advanced Institutes of Convergence Technology, Kwanggyo Technovalley, Suwon, 16229, Republic of Korea
| | - Goo Jang
- Department of Theriogenology, College of Veterinary Medicine and the Research Institute of Veterinary Science, Seoul National University, #631 Building 85, Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea. .,Emergence Center for Food-Medicine Personalized Therapy System, Advanced Institutes of Convergence Technology, Seoul National University, Gyeonggi-do, 16229, Republic of Korea.
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Robinson J, Lu P. Optimization of trophic support for neural stem cell grafts in sites of spinal cord injury. Exp Neurol 2017; 291:87-97. [DOI: 10.1016/j.expneurol.2017.02.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/30/2017] [Accepted: 02/07/2017] [Indexed: 11/30/2022]
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9
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Cheng JK, Lewis AM, Kim DS, Dyess T, Alper HS. Identifying and retargeting transcriptional hot spots in the human genome. Biotechnol J 2016; 11:1100-9. [PMID: 27311394 DOI: 10.1002/biot.201600015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 05/18/2016] [Accepted: 05/30/2016] [Indexed: 01/17/2023]
Abstract
Mammalian cell line development requires streamlined methodologies that will reduce both the cost and time to identify candidate cell lines. Improvements in site-specific genomic editing techniques can result in flexible, predictable, and robust cell line engineering. However, an outstanding question in the field is the specific site of integration. Here, we seek to identify productive loci within the human genome that will result in stable, high expression of heterologous DNA. Using an unbiased, random integration approach and a green fluorescent reporter construct, we identify ten single-integrant, recombinant human cell lines that exhibit stable, high-level expression. From these cell lines, eight unique corresponding integration loci were identified. These loci are concentrated in non-protein coding regions or intronic regions of protein coding genes. Expression mapping of the surrounding genes reveals minimal disruption of endogenous gene expression. Finally, we demonstrate that targeted de novo integration at one of the identified loci, the 12(th) exon-intron region of the GRIK1 gene on chromosome 21, results in superior expression and stability compared to the standard, illegitimate integration approach at levels approaching 4-fold. The information identified here along with recent advances in site-specific genomic editing techniques can lead to expedited cell line development.
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Affiliation(s)
- Joseph K Cheng
- Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Amanda M Lewis
- Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA.,Biologics Development, Bristol-Myers Squibb, Devens, MA, USA
| | - Do Soon Kim
- Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Timothy Dyess
- Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Hal S Alper
- Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA. .,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, USA.
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10
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Lu P, Graham L, Wang Y, Wu D, Tuszynski M. Promotion of survival and differentiation of neural stem cells with fibrin and growth factor cocktails after severe spinal cord injury. J Vis Exp 2014:e50641. [PMID: 25145787 DOI: 10.3791/50641] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Neural stem cells (NSCs) can self-renew and differentiate into neurons and glia. Transplanted NSCs can replace lost neurons and glia after spinal cord injury (SCI), and can form functional relays to re-connect spinal cord segments above and below a lesion. Previous studies grafting neural stem cells have been limited by incomplete graft survival within the spinal cord lesion cavity. Further, tracking of graft cell survival, differentiation, and process extension had not been optimized. Finally, in previous studies, cultured rat NSCs were typically reported to differentiate into glia when grafted to the injured spinal cord, rather than neurons, unless fate was driven to a specific cell type. To address these issues, we developed new methods to improve the survival, integration and differentiation of NSCs to sites of even severe SCI. NSCs were freshly isolated from embryonic day 14 spinal cord (E14) from a stable transgenic Fischer 344 rat line expressing green fluorescent protein (GFP) and were embedded into a fibrin matrix containing growth factors; this formulation aimed to retain grafted cells in the lesion cavity and support cell survival. NSCs in the fibrin/growth factor cocktail were implanted two weeks after thoracic level-3 (T3) complete spinal cord transections, thereby avoiding peak periods of inflammation. Resulting grafts completely filled the lesion cavity and differentiated into both neurons, which extended axons into the host spinal cord over remarkably long distances, and glia. Grafts of cultured human NSCs expressing GFP resulted in similar findings. Thus, methods are defined for improving neural stem cell grafting, survival and analysis of in vivo findings.
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Affiliation(s)
- Paul Lu
- Veterans Administration Medical Center, San Diego; Department of Neurosciences, University of California, San Diego;
| | - Lori Graham
- Department of Neurosciences, University of California, San Diego
| | - Yaozhi Wang
- Department of Neurosciences, University of California, San Diego
| | - Di Wu
- Department of Neurosciences, University of California, San Diego
| | - Mark Tuszynski
- Veterans Administration Medical Center, San Diego; Department of Neurosciences, University of California, San Diego
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Bock AS, Leigh ND, Bryda EC. Effect of Gsk3 inhibitor CHIR99021 on aneuploidy levels in rat embryonic stem cells. In Vitro Cell Dev Biol Anim 2014; 50:572-9. [PMID: 24519175 PMCID: PMC4062835 DOI: 10.1007/s11626-014-9734-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 01/15/2014] [Indexed: 01/16/2023]
Abstract
Germline competent embryonic stem (ES) cells can serve as a tool to create genetically engineered rat strains used to elucidate gene function or provide disease models. In optimum culture conditions, ES cells are able to retain their pluripotent state. The type of components present and their concentration in ES cell culture media greatly influences characteristics of ES cells including the ability to maintain the cells in a pluripotent state. We routinely use 2i media containing inhibitors CHIR99021 and PD0325901 to culture rat ES cells. CHIR99021 specifically inhibits the Gsk3β pathway. We have found that the vendor source of CHIR99021 has a measurable influence on the level of aneuploidy seen over time as rat ES cells are passaged. Karyotyping of three different rat ES cell lines passaged multiple times showed increased aneuploidy when CHIR99021 from source B was used. Mass spectrometry analysis of this inhibitor showed the presence of unexpected synthetic small molecules, which might directly or indirectly cause increases in chromosome instability. Identifying these molecules could further understanding of their influence on chromosome stability and indicate how to improve synthesis of this media component to prevent deleterious effects in culture.
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Affiliation(s)
- Anagha S Bock
- Rat Resource and Research Center, Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, 4011 Discovery Drive, Columbia, MO, 65201, USA
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Men H, Bryda EC. Derivation of a germline competent transgenic Fischer 344 embryonic stem cell line. PLoS One 2013; 8:e56518. [PMID: 23437152 PMCID: PMC3577902 DOI: 10.1371/journal.pone.0056518] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/12/2013] [Indexed: 11/24/2022] Open
Abstract
Embryonic stem (ES) cell-based gene manipulation is an effective method for the generation of mutant animal models in mice and rats. Availability of germline-competent ES cell lines from inbred rat strains would allow for creation of new genetically modified models in the desired genetic background. Fischer344 (F344) males carrying an enhanced green fluorescence protein (EGFP) transgene were used as the founder animals for the derivation of ES cell lines. After establishment of ES cell lines, rigorous quality control testing that included assessment of pluripotency factor expression, karyotype analysis, and pathogen/sterility testing was conducted in selected ES cell lines. One male ES cell line, F344-Tg.EC4011, was further evaluated for germline competence by injection into Dark Agouti (DA) X Sprague Dawley (SD) blastocysts. Resulting chimeric animals were bred with wild-type SD mates and germline transmissibility of the ES cell line was confirmed by identification of pups carrying the ES cell line-derived EGFP transgene. This is the first report of a germline competent F344 ES cell line. The availability of a new germline competent ES cell line with a stable fluorescence reporter from an inbred transgenic rat strain provides an important new resource for genetic manipulations to create new rat models.
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Affiliation(s)
- Hongsheng Men
- Rat Resource and Research Center, Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri, United States of America
| | - Elizabeth C. Bryda
- Rat Resource and Research Center, Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri, United States of America
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Lu P, Wang Y, Graham L, McHale K, Gao M, Wu D, Brock J, Blesch A, Rosenzweig ES, Havton LA, Zheng B, Conner JM, Marsala M, Tuszynski MH. Long-distance growth and connectivity of neural stem cells after severe spinal cord injury. Cell 2012; 150:1264-73. [PMID: 22980985 DOI: 10.1016/j.cell.2012.08.020] [Citation(s) in RCA: 636] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 05/02/2012] [Accepted: 08/20/2012] [Indexed: 12/30/2022]
Abstract
Neural stem cells (NSCs) expressing GFP were embedded into fibrin matrices containing growth factor cocktails and grafted to sites of severe spinal cord injury. Grafted cells differentiated into multiple cellular phenotypes, including neurons, which extended large numbers of axons over remarkable distances. Extending axons formed abundant synapses with host cells. Axonal growth was partially dependent on mammalian target of rapamycin (mTOR), but not Nogo signaling. Grafted neurons supported formation of electrophysiological relays across sites of complete spinal transection, resulting in functional recovery. Two human stem cell lines (566RSC and HUES7) embedded in growth-factor-containing fibrin exhibited similar growth, and 566RSC cells supported functional recovery. Thus, properties intrinsic to early-stage neurons can overcome the inhibitory milieu of the injured adult spinal cord to mount remarkable axonal growth, resulting in formation of new relay circuits that significantly improve function. These therapeutic properties extend across stem cell sources and species.
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Affiliation(s)
- Paul Lu
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
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Abstract
As the number of transgenic livestock increases, reliable detection and molecular characterization of transgene integration sites and copy number are crucial not only for interpreting the relationship between the integration site and the specific phenotype but also for commercial and economic demands. However, the ability of conventional PCR techniques to detect incomplete and multiple integration events is limited, making it technically challenging to characterize transgenes. Next-generation sequencing has enabled cost-effective, routine and widespread high-throughput genomic analysis. Here, we demonstrate the use of next-generation sequencing to extensively characterize cattle harboring a 150-kb human lactoferrin transgene that was initially analyzed by chromosome walking without success. Using this approach, the sites upstream and downstream of the target gene integration site in the host genome were identified at the single nucleotide level. The sequencing result was verified by event-specific PCR for the integration sites and FISH for the chromosomal location. Sequencing depth analysis revealed that multiple copies of the incomplete target gene and the vector backbone were present in the host genome. Upon integration, complex recombination was also observed between the target gene and the vector backbone. These findings indicate that next-generation sequencing is a reliable and accurate approach for the molecular characterization of the transgene sequence, integration sites and copy number in transgenic species.
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Men H, Bauer BA, Bryda EC. Germline transmission of a novel rat embryonic stem cell line derived from transgenic rats. Stem Cells Dev 2012; 21:2606-12. [PMID: 22455749 PMCID: PMC3438845 DOI: 10.1089/scd.2012.0040] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 03/25/2012] [Indexed: 01/30/2023] Open
Abstract
Germline-competent rat embryonic stem (ES) cell lines are important resources for the creation of mutant rat models using ES-cell-based gene targeting technology. The ability to isolate germline-competent ES cell lines from any rat strain, including genetically modified strains, would allow for more sophisticated genetic manipulations without extensive breeding. Sprague Dawley (SD) males carrying an enhanced green fluorescent protein (EGFP) transgene were used as the founder animals for the derivation of ES cell lines. A number of ES cell lines were established and subjected to rigorous quality control testing that included assessment of pluripotency factor expression, karyotype analysis, and pathogen/sterility testing. Two male ES cell lines, SD-Tg.EC1/Rrrc and SD-Tg.EC8/Rrrc, were injected into blastocysts recovered from a cross of Dark Agouti (DA) males with SD females. Resulting chimeric animals were bred with wild-type SD mates to verify the germline transmissibility of the ES cell lines by identifying pups carrying the ES cell line-derived EGFP transgene. While both ES cell lines gave rise to chimeric animals, only SD-Tg.EC1 was germline competent. This confirms the feasibility of deriving germline-competent ES cell lines from transgenic rat strains and provides a novel ES cell line with a stable green fluorescent protein (GFP) reporter for future genetic manipulations to create new rat models.
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Affiliation(s)
- Hongsheng Men
- Department of Veterinary Pathobiology, Rat Resource and Research Center, University of Missouri, Columbia, Missouri 65201, USA
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Tóth DM, Szőke É, Bölcskei K, Kvell K, Bender B, Bősze Z, Szolcsányi J, Sándor Z. Nociception, neurogenic inflammation and thermoregulation in TRPV1 knockdown transgenic mice. Cell Mol Life Sci 2011; 68:2589-601. [PMID: 21069423 PMCID: PMC11115187 DOI: 10.1007/s00018-010-0569-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 09/17/2010] [Accepted: 10/14/2010] [Indexed: 01/28/2023]
Abstract
Transgenic mice with a small hairpin RNA construct interfering with the expression of transient receptor potential vanilloid 1 (TRPV1) were created by lentiviral transgenesis. TRPV1 expression level in transgenic mice was reduced to 8% while the expression of ankyrin repeat domain 1 (TRPA1) was unchanged. Ear oedema induced by topical application of TRPV1 agonist capsaicin was completely absent in TRPV1 knockdown mice. Thermoregulatory behaviour in relation to environmental thermopreference (30 vs. 35°C) was slightly impaired in male knockdown mice, but the reduction of TRPV1 function was not associated with enhanced hyperthermia. TRPV1 agonist resiniferatoxin induced hypothermia and tail vasodilatation was markedly inhibited in knockdown mice. In conclusion, shRNA-mediated knock down of the TRPV1 receptor in mice induced robust inhibition of the responses to TRPV1 agonists without altering the expression, gating function or neurogenic oedema provoked by TRPA1 activation. Thermoregulatory behaviour in response to heat was inhibited, but enhanced hyperthermia was not observed.
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Affiliation(s)
- Dániel Márton Tóth
- Analgesics Research Laboratory, University of Pécs and Gedeon Richter PLC, Szigeti út 12, Pécs, 7624 Hungary
| | - Éva Szőke
- Analgesics Research Laboratory, University of Pécs and Gedeon Richter PLC, Szigeti út 12, Pécs, 7624 Hungary
| | - Kata Bölcskei
- Analgesics Research Laboratory, University of Pécs and Gedeon Richter PLC, Szigeti út 12, Pécs, 7624 Hungary
| | - Krisztián Kvell
- Department of Immunology and Biotechnology, University of Pécs, Pécs, 7624 Hungary
| | - Balázs Bender
- Agricultural Biotechnology Center, Gödöllő, 2100 Hungary
| | | | - János Szolcsányi
- Analgesics Research Laboratory, University of Pécs and Gedeon Richter PLC, Szigeti út 12, Pécs, 7624 Hungary
| | - Zoltán Sándor
- Analgesics Research Laboratory, University of Pécs and Gedeon Richter PLC, Szigeti út 12, Pécs, 7624 Hungary
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Marchini C, Gabrielli F, Iezzi M, Zenobi S, Montani M, Pietrella L, Kalogris C, Rossini A, Ciravolo V, Castagnoli L, Tagliabue E, Pupa SM, Musiani P, Monaci P, Menard S, Amici A. The human splice variant Δ16HER2 induces rapid tumor onset in a reporter transgenic mouse. PLoS One 2011; 6:e18727. [PMID: 21559085 PMCID: PMC3084693 DOI: 10.1371/journal.pone.0018727] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 03/16/2011] [Indexed: 11/18/2022] Open
Abstract
Several transgenic mice models solidly support the hypothesis that HER2 (ERBB2) overexpression or mutation promotes tumorigenesis. Recently, a HER2 splice variant lacking exon-16 (Δ16HER2) has been detected in human breast carcinomas. This alternative protein, a normal byproduct of HER2, has an increased transforming potency compared to wild-type (wt) HER2 receptors. To examine the ability of Δ16HER2 to transform mammary epithelium in vivo and to monitor Δ16HER2-driven tumorigenesis in live mice, we generated and characterized a mouse line that transgenically expresses both human Δ16HER2 and firefly luciferase under the transcriptional control of the MMTV promoter. All the transgenic females developed multifocal mammary tumors with a rapid onset and an average latency of 15.11 weeks. Immunohistochemical analysis revealed the concurrent expression of luciferase and the human Δ16HER2 oncogene only in the mammary gland and in strict correlation with tumor development. Transgenic Δ16HER2 expressed on the tumor cell plasma membrane from spontaneous mammary adenocarcinomas formed constitutively active homodimers able to activate the oncogenic signal transduction pathway mediated through Src kinase. These new transgenic animals demonstrate the ability of the human Δ16HER2 isoform to transform "per se" mammary epithelium in vivo. The high tumor incidence as well as the short latency strongly suggests that the Δ16HER2 splice variant represents the transforming form of the HER2 oncoprotein.
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Affiliation(s)
- Cristina Marchini
- Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy
| | - Federico Gabrielli
- Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy
| | - Manuela Iezzi
- Aging Research Centre, G. d'Annunzio University, Chieti, Italy
| | - Santa Zenobi
- Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy
| | - Maura Montani
- Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy
| | - Lucia Pietrella
- Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy
| | - Cristina Kalogris
- Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy
| | - Anna Rossini
- Molecular Targeting Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS, Istituto Nazionale dei Tumori, AmadeoLab, Milan, Italy
| | - Valentina Ciravolo
- Molecular Targeting Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS, Istituto Nazionale dei Tumori, AmadeoLab, Milan, Italy
| | - Lorenzo Castagnoli
- Molecular Targeting Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS, Istituto Nazionale dei Tumori, AmadeoLab, Milan, Italy
| | - Elda Tagliabue
- Molecular Targeting Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS, Istituto Nazionale dei Tumori, AmadeoLab, Milan, Italy
| | - Serenella M. Pupa
- Molecular Targeting Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS, Istituto Nazionale dei Tumori, AmadeoLab, Milan, Italy
| | - Piero Musiani
- Aging Research Centre, G. d'Annunzio University, Chieti, Italy
| | - Paolo Monaci
- Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy
| | - Sylvie Menard
- Molecular Targeting Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS, Istituto Nazionale dei Tumori, AmadeoLab, Milan, Italy
| | - Augusto Amici
- Department of Bioscience and Biotechnology, University of Camerino, Camerino, Italy
- * E-mail:
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Bressan FF, Dos Santos Miranda M, Perecin F, De Bem TH, Pereira FTV, Russo-Carbolante EM, Alves D, Strauss B, Bajgelman M, Krieger JE, Binelli M, Meirelles FV. Improved production of genetically modified fetuses with homogeneous transgene expression after transgene integration site analysis and recloning in cattle. Cell Reprogram 2011; 13:29-36. [PMID: 21241190 DOI: 10.1089/cell.2010.0022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Animal cloning by nuclear transfer (NT) has made the production of transgenic animals using genetically modified donor cells possible and ensures the presence of the gene construct in the offspring. The identification of transgene insertion sites in donor cells before cloning may avoid the production of animals that carry undesirable characteristics due to positional effects. This article compares blastocyst development and competence to establish pregnancies of bovine cloned embryos reconstructed with lentivirus-mediated transgenic fibroblasts containing either random integration of a transgene (random integration group) or nuclear transfer derived transgenic fibroblasts with known transgene insertion sites submitted to recloning (recloned group). In the random integration group, eGFP-expressing bovine fetal fibroblasts were selected by fluorescence activated cell sorting (FACS) and used as nuclei donor cells for NT. In the recloned group, a fibroblast cell line derived from a transgenic cloned fetus was characterized regarding transgene insertion and submitted to recloning. The recloned group had higher blastocyst production (25.38 vs. 14.42%) and higher percentage of 30-day pregnancies (14.29 vs. 2.56%) when compared to the random integration group. Relative eGFP expression analysis in fibroblasts derived from each cloned embryo revealed more homogeneous expression in the recloned group. In conclusion, the use of cell lines recovered from transgenic fetuses after identification of the transgene integration site allowed for the production of cells and fetuses with stable transgene expression, and recloning may improve transgenic animal yields.
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Sheng Y, Lin CC, Yue J, Sukhwani M, Shuttleworth JJ, Chu T, Orwig KE. Generation and characterization of a Tet-On (rtTA-M2) transgenic rat. BMC DEVELOPMENTAL BIOLOGY 2010; 10:17. [PMID: 20158911 PMCID: PMC2834583 DOI: 10.1186/1471-213x-10-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 02/16/2010] [Indexed: 01/09/2023]
Abstract
Background The tetracycline-inducible gene regulation system is a powerful tool that allows temporal and dose-dependent regulation of target transgene expression in vitro and in vivo. Several tetracycline-inducible transgenic mouse models have been described with ubiquitous or tissue-specific expression of tetracycline-transactivator (tTA), reverse tetracycline-transactivator (rtTA) or Tet repressor (TetR). Here we describe a Tet-On transgenic rat that ubiquitously expresses rtTA-M2 driven by the murine ROSA 26 promoter. Results The homozygous rat line (ROSA-rtTA-M2) generated by lentiviral vector injection, has a single integration site and was derived from the offspring of a genetic mosaic founder with multiple transgene integrations. The rtTA-M2 transgene integrated into an intron of a putative gene on chromosome 2 and does not appear to affect the tissue-specificity or expression of that gene. Fibroblasts from the ROSA-rtTA-M2 rats were transduced with a TetO7/CMV-EGFP lentivirus and exhibited doxycycline dose-dependent expression of the EGFP reporter transgene, in vitro. In addition, doxycycline-inducible EGFP expression was observed, in vivo, when the TetO7/CMV-EGFP lentivirus was injected into testis, kidney and muscle tissues of ROSA-rtTA-M2 rats. Conclusions This conditional expression rat model may have application for transgenic overexpression or knockdown studies of gene function in development, disease and gene therapy.
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Affiliation(s)
- Yi Sheng
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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Bryda EC, Bauer BA. A restriction enzyme-PCR-based technique to determine transgene insertion sites. Methods Mol Biol 2010; 597:287-99. [PMID: 20013241 DOI: 10.1007/978-1-60327-389-3_20] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Currently, most genetically engineered rat strains are created by methods that involve random integration of transgenes into the genome. The ability to identify the chromosomal location of the transgene insertion site enables the development of efficient genotyping assays, allows segregation of multiple transgene integration sites to be followed while breeding, and facilitates characterization of possible positional effects on phenotype. Here we describe a method for determining the chromosomal location of transgene insertion that combines restriction endonuclease enzyme digest with subsequent rounds of PCR amplification to produce amplicons representing the chromosomal regions flanking the integrated transgene. This method provides a reliable means for determining the exact location of insertion of transgenes within the genome.
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Affiliation(s)
- Elizabeth C Bryda
- Research Animal Diagnostic Laboratory, University of Missouri, Columbia, MO, USA
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21
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Remy S, Nguyen TH, Ménoret S, Tesson L, Usal C, Anegon I. The use of lentiviral vectors to obtain transgenic rats. Methods Mol Biol 2010; 597:109-25. [PMID: 20013229 DOI: 10.1007/978-1-60327-389-3_8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Lentiviral vectors are now well recognized as good vehicles for gene delivery. This is because they can efficiently transduce both dividing and post-mitotic cells, and stably integrate into the host genome allowing for long-term expression of the transgene. Their potential utility for the generation of transgenic animals has been recognized as an attractive and promising alternative to the conventional DNA-microinjection method which lacks efficiency. The initial success of lentiviral transgenesis in mice considerably broadened its use in other species, in which classical transgenic techniques are difficult, such as in the rat.In this chapter, we describe detailed procedures for both the production of human immunodeficiency virus-1 (HIV-1)-derived lentiviral vectors and for the generation of transgenic rats by injection of these vectors into the perivitelline space of fertilized one-cell eggs.
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22
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Horn NL, Donkin SS, Applegate TJ, Adeola O. Intestinal mucin dynamics: response of broiler chicks and White Pekin ducklings to dietary threonine. Poult Sci 2009; 88:1906-14. [PMID: 19687276 DOI: 10.3382/ps.2009-00009] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mucin dynamics may be particularly sensitive to a Thr deficiency due to the high concentration and structural importance of Thr in the mucin protein backbone. Intestinal mucin secretion, expression of mucin gene (MUC2), and histological characteristics were investigated in male broilers and White Pekin ducklings offered diets containing 3.3, 5.8, or 8.2 g of Thr/kg in 4 studies. Seventy-two birds of each species were fed a standard broiler starter diet from 1 to 14 d of age followed by assignment to 3 dietary treatments in a randomized complete block design for a 7-d feeding trial in experiment 1 (broilers) and experiment 2 (ducklings). The dietary treatments consisted of an isonitrogenous corn-soybean meal-based diet with the addition of crystalline amino acids and graded levels of Thr. Dietary treatments contained 3.3, 5.8, or 8.2 g of Thr/kg. Dietary formulation and experimental design for experiments 3 (broilers) and 4 (ducklings) were similar to experiments 1 and 2 except that birds were fed 3.3 or 8.2 g of Thr/kg for durations of 7 or 14 d. For chicks, increased dietary Thr resulted in higher levels of intestinal crude mucin excretion in experiment 1 (P=0.04) but not in experiment 3, whereas intestinal sialic acid excretion increased in experiment 3 (P=0.02) but not in experiment 1. Furthermore, there was no effect of Thr on intestinal goblet cell density or MUC2 mRNA abundance for broilers. For ducklings, there was an increase in intestinal crude mucin excretion in both experiments (P<0.05) as dietary Thr increased, although there was no effect of Thr on intestinal sialic acid excretion. There was a tendency for an increase in intestinal goblet cell density (cells/microm of villus length; P=0.09) as dietary Thr increased in experiment 2. For experiment 4, intestinal MUC2 mRNA abundance increased (P=0.03) as dietary Thr increased for the 14-d feeding trial but not for the 7-d feeding trial. The data establish a link between dietary Thr and intestinal crude mucin dynamics in chicks for experiment 1 and ducklings for both experiments.
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Affiliation(s)
- N L Horn
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA
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23
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Yang SH, Cheng PH, Sullivan RT, Thomas JW, Chan AWS. Lentiviral integration preferences in transgenic mice. Genesis 2009; 46:711-8. [PMID: 18821598 DOI: 10.1002/dvg.20435] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Lentiviral gene transfer has a significant impact on the development of biomedical research. One of the most important features of lentiviruses is the capability to infect both dividing and nondividing cells. However, little is known whether integration preference exists, specifically in early embryos. An in-depth genome analysis on 112 independent lentiviral integration sites from 43 transgenic founder mice was performed to determine if there are preferable sites for lentiviral integration in early embryonic genome. Our results demonstrated that lentiviruses were biased in integrating within intragenic regions, especially in the introns. However, no integration preference was found associated with specific chromosomes, repetitive elements, or CpG islands, nor was there any preference for integrating at close proximity to transcription start sites. Our findings suggested that lentiviruses were biased to integrate into the intragenic regions of early embryonic genome of mouse.
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Affiliation(s)
- Shang-Hsun Yang
- Division of Neuroscience, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road N.E., Atlanta, GA 30329, USA
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Agca C, Seye C, Kashuba Benson CM, Rikka S, Chan AWS, Weisman GA, Agca Y. Development of a novel transgenic rat overexpressing the P2Y(2) nucleotide receptor using a lentiviral vector. J Vasc Res 2009; 46:447-58. [PMID: 19155635 DOI: 10.1159/000194274] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 09/14/2008] [Indexed: 11/19/2022] Open
Abstract
The G protein-coupled P2Y(2) nucleotide receptor (P2Y(2)R) is upregulated in response to stress and tissue injury and has been postulated to play a role in chronic inflammation seen in atherosclerosis, Alzheimer's disease and Sjogren's syndrome. The role of P2Y(2)R upregulation in vivo is poorly understood, in part due to the lack of a P2Y(2)R overexpressing animal model. The P2Y(2)R overexpressing transgenic rat was generated using a lentiviral vector. Rats overexpressing P2Y(2)R showed a significant increase in P2Y(2)R mRNA levels in all tissues screened as compared to nontransgenic rats. Fura 2 imaging of smooth muscle cells (SMCs) isolated from aorta indicated that the percentage of cells exhibiting increases in the intracellular free calcium concentration in response to P2Y(2)R agonists was significantly greater in freshly isolated SMCs from transgenic rats than wild-type controls. Histopathological examination of tissues revealed that P2Y(2)R overexpressing rats develop lymphocytic infiltration in lacrimal glands and kidneys as early as at 3 months of age. These rats show similarities to patients with Sjogren's syndrome who display lymphocyte-mediated tissue damage. This transgenic rat model of P2Y(2)R overexpression may prove useful for linking P2Y(2)R upregulation with chronic inflammatory diseases, neurodegenerative diseases and Sjogren's syndrome.
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Affiliation(s)
- Cansu Agca
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Mo. 65211, USA
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25
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Baska KM, Manandhar G, Feng D, Agca Y, Tengowski MW, Sutovsky M, Yi YJ, Sutovsky P. Mechanism of extracellular ubiquitination in the mammalian epididymis. J Cell Physiol 2008; 215:684-96. [PMID: 18064599 DOI: 10.1002/jcp.21349] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Posttranslational modification by ubiquitination marks defective or outlived intracellular proteins for proteolytic degradation by the 26S proteasome. The ATP-dependent, covalent ligation and formation of polyubiquitin chains on substrate proteins requires the presence and activity of a set of ubiquitin activating and conjugating enzymes. While protein ubiquitination typically occurs in the cell cytosol or nucleus, defective mammalian spermatozoa become ubiquitinated on their surface during post-testicular sperm maturation in the epididymis, suggesting an active molecular mechanism for sperm quality control. Consequently, we hypothesized that the bioactive constituents of ubiquitin-proteasome pathway were secreted in the mammalian epididymal fluid (EF) and capable of ubiquitinating extrinsic substrates. Western blotting indeed detected the presence of the ubiquitin-activating enzyme E1 and presumed E1-ubiquitin thiol-ester intermediates, ubiquitin-carrier enzyme E2 and presumed E2-ubiquitin thiol-ester intermediates and the ubiquitin C-terminal hydrolase PGP 9.5/UCHL1 in the isolated bovine EF. Thiol-ester assays utilizing recombinant ubiquitin-activating and ubiquitin-conjugating enzymes, biotinylated substrates, and isolated bovine EF confirmed the activity of the ubiquitin activating and conjugating enzymes within EF. Ubiquitinated proteins were found to be enriched in the defective bull sperm fraction and appropriate proteasomal deubiquitinating and proteolytic activities were measured in the isolated EF by specific fluorescent substrates. The apocrine secretion of cytosolic proteins was visualized in transgenic mice and rats expressing the enhanced green fluorescent protein (eGFP) under the direction of ubiquitin-C promoter. Accumulation of eGFP, ubiquitin and proteasomes was detected in the apical blebs, the apocrine secretion sites of the caput epididymal epithelia of both the rat and mouse epididymal epithelium, although region-specific differences exist. Secretion of eGFP and proteasomes continued during the prolonged culture of the isolated rat epididymal epithelial cells in vitro. This study provides evidence that the activity of the ubiquitin system is not limited to the intracellular environment, contributing to a greater understanding of the sperm maturation process during epididymal passage.
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Affiliation(s)
- Kathleen M Baska
- Division of Animal Sciences, University of Missouri-Columbia, Columbia, Missouri, USA
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Abstract
Transgenic mice have been instrumental in dissecting the role of various neuronal proteins under both physiological and pathological conditions. Pronuclear injection is the most widely used protocol for the generation of transgenic mice. Here, we describe all steps involved from DNA purification to the set up of a mouse colony including vasectomy, injection of the DNA into a donor zygote, transfer of injected zygotes into recipient foster mice, screening of offspring and establishment of transgenic mouse lines. We discuss the use of neuron-specific promoters to express proteins with a role in Alzheimer disease. Transgenic expression of a truncated form of the microtubule-associated protein tau (delta tau) is used as an example for the anticipated results.
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Affiliation(s)
- Lars M Ittner
- Alzheimer's & Parkinson's Disease Laboratory, Brain & Mind Research Institute, University of Sydney, 100, Mallett Street, Camperdown, New South Wales 2050, Australia
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Abstract
Lentiviral vectors have become a promising new tool for the establishment of transgenic animals and the manipulation of the mammalian genome. While conventional microinjection-based methods for transgenesis have been successful in generating small and large transgenic animals, their relatively low transgenic efficiency has opened the door for alternative approaches, including lentiviral vectors. Lentiviral vectors are an appealing tool for transgenesis in part because of their ability to incorporate into genomic DNA with high efficiency, especially in cells that are not actively dividing. Lentiviral vector-mediated transgene expression can also be maintained for long periods of time. Recent studies have documented high efficiencies for lentiviral transgenesis, even in animal species and strains, such as NOD/ scid and C57Bl/6 mouse, that are very difficult to manipulate using the standard transgenic techniques. These advantages of the lentiviral vector system have broadened its use as a gene therapy vector to additional applications that include transgenesis and knockdown functional genetics. This review will address the components of the lentiviral vector system and recent successes in lentiviral transgenesis using both male- and female-derived pluripotent cells. The advantages and disadvantages of lentiviral transgenesis vs. other approaches to produce transgenic animals will be compared with regard to efficiency, the ability to promote persistent transgene expression, and the time necessary to generate a sufficient number of animals for phenotyping.
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Affiliation(s)
- Frank Park
- Department of Medicine, Kidney Disease Center, Medical College of Wisconsin, Wauwatosa, Wisconsin 53226, USA.
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28
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Michalkiewicz M, Michalkiewicz T, Geurts AM, Roman RJ, Slocum GR, Singer O, Weihrauch D, Greene AS, Kaldunski M, Verma IM, Jacob HJ, Cowley AW. Efficient transgenic rat production by a lentiviral vector. Am J Physiol Heart Circ Physiol 2007; 293:H881-94. [PMID: 17322424 DOI: 10.1152/ajpheart.00060.2007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A lentiviral construct for an enhanced green fluorescent protein (eGFP) driven by a chicken beta-actin promoter, cytomegalovirus enhancer, and intronic sequences from rabbit beta-globin (CAG) was used to produce transgenic lines of rats for evaluation of the usefulness of this approach in gene function studies. Fertilized eggs were collected from inbred Dahl S and outbred Sprague-Dawley rats, and approximately 100 pl of concentrated virus were microinjected into the perivitrelline space of one-cell embryos. Of 121 embryos injected, 60 pups (49.6%) were born. Transgenic rates averaged 22% in Dahl S and 14% in Sprague-Dawley rats. Copy number ranged from one to four in the founders, and the inheritance of the transgene in a subsequent F(1) population was 48.2%. The small number of insertion sites enabled us to derive inbred transgenic lines with a single copy of the transgene within one generation. Sequencing of each transgene insertion site revealed that they inserted as single copies with a preference for the introns of genes. The CAG promoter drove high levels of eGFP expression in brain, kidney, heart, and vasculature, making it very suitable for exploring the cardiovascular function of newly discovered genes. The pattern of eGFP expression was similar across five different F(1) transgenic lines, indicating that the expression of the transgene was independent of its chromosomal position. Thus lentiviral transgenesis provides a powerful tool for the production of transgenic inbred rats and will enhance the usefulness of this species in gene discovery and target validation studies.
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Affiliation(s)
- Mieczyslaw Michalkiewicz
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA.
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