In vivo mutagenicity and DNA adduct levels of heterocyclic amines in Muta™Mice and c-myclacZ double transgenic mice

Background and Purpose: Small ubiquitin-like modifier (SUMO) conjugation modulates many key cellular processes. Transient cerebral ischemia dramatically activates SUMO2/3 conjugation, and this is believed to be a protective stress response. It is, therefore, of tremendous clinical interest to characterize the SUMO-modified proteome regulated by transient ischemia. We generated a novel SUMO transgenic mouse and performed the first SUMO proteomics study using post-ischemic brain samples. Methods: CAG-loxP-STOP-loxP-SUMO (CAG-SUMO) mice were generated in which His-SUMO1, HA-SUMO2, and FLAG-SUMO3 were expressed from a single multicistronic transgene in a Cre-dependent manner. CAG-SUMO mice were mated with Emx1 Cre/Cre mice to generate double transgenic CAG-SUMO/Emx1-Cre mice as experimental mice and Emx1 Cre/+ mice as control mice. Double transgenic mice were subjected to 10 min global cerebral ischemia followed by 1 h reperfusion or sham operation. FLAG-SUMO3-conjugated proteins were enriched from cortical tissues and analyzed. Results: Characterization of double transgenic mice demonstrated that exogenous expressed tagged SUMO paralogues were functionally intact and did not perturb the endogenous SUMOylation machinery in the brain. FLAG pulldown of cortical samples from sham and ischemia mice followed by GeLC-MS/MS analysis identified 91 candidates whose SUMOylation states were up-regulated in ischemic samples. Data analysis revealed several potentially important processes in which SUMO3 conjugation may play a key role during ischemia/reperfusion, including the cross-talk between SUMOylation and ubiquitination, glucocorticoid receptor signaling, and modulation of posttranscriptional mRNA processing. Conclusions: SUMO proteomic analysis identified important processes and pathways modulated by SUMOylation in the post-ischemic brain that warrant future investigations, since they could be the key to understand the overall impact of SUMOylation on the fate and functions of post-ischemic neurons. The conditional SUMO transgenic mouse will be an invaluable tool for in-depth in vivo analysis of the SUMO-modified proteome in various pathological states.

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Generation of Fad2 and Fad3 transgenic mice that produce n-6 and n-3 polyunsaturated fatty acids

Open Biology ◽

10.1098/rsob.190140 ◽

2019 ◽

Vol 9 (10) ◽

pp. 190140 ◽

Cited By ~ 1

Author(s):

Lishuang Song ◽

Lei Yang ◽

Jiapeng Wang ◽

Xuefei Liu ◽

Lige Bai ◽

...

Keyword(s):

Fatty Acids ◽

Transgenic Mice ◽

Polyunsaturated Fatty Acids ◽

Critical Role ◽

Fatty Acid Desaturase ◽

Biosynthetic Pathways ◽

Wild Type ◽

Pufa Biosynthesis ◽

Double Transgenic Mice

Linoleic acid (18 : 2, n-6) and α-linolenic acid (18 : 3, n-3) are polyunsaturated fatty acids (PUFAs), which are essential for mammalian health, development and growth. However, the majority of mammals, including humans, are incapable of synthesizing n-6 and n-3 PUFAs. Mammals must obtain n-6 and n-3 PUFAs from their diet. Fatty acid desaturase (Fad) plays a critical role in plant PUFA biosynthesis. Therefore, we generated plant-derived Fad3 single and Fad2–Fad3 double transgenic mice. Compared with wild-type mice, we found that PUFA levels were greatly increased in the single and double transgenic mice by measuring PUFA levels. Moreover, the concentration of n-6 and n-3 PUFAs in the Fad2–Fad3 double transgenic mice were greater than in the Fad3 single transgenic mice. These results demonstrate that the plant-derived Fad2 and Fad3 genes can be expressed in mammals. To clarify the mechanism for Fad2 and Fad3 genes in transgenic mice, we measured the PUFAs synthesis-related genes. Compared with wild-type mice, these Fad transgenic mice have their own n-3 and n-6 PUFAs biosynthetic pathways. Thus, we have established a simple and efficient method for in vivo synthesis of PUFAs.

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A haplotype of human angiotensinogen gene containing −217A increases blood pressure in transgenic mice compared with −217G

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.90637.2008 ◽

2008 ◽

Vol 295 (6) ◽

pp. R1849-R1857 ◽

Cited By ~ 16

Author(s):

Sudhir Jain ◽

Govindaiah Vinukonda ◽

Steven N. Fiering ◽

Ashok Kumar

Keyword(s):

Blood Pressure ◽

Transgenic Mice ◽

Mrna Level ◽

Human Renin ◽

Renin Gene ◽

Plasma Angiotensin ◽

Double Transgenic Mice ◽

Agt Gene

The human angiotensinogen (hAGT) gene contains an A/G polymorphism at −217, and frequency of −217A allele is increased in African-American hypertensive patients. The hAGT gene has seven polymorphic sites in the 1.2-kb region of its promoter, and variant −217A almost always occurs with −532T, −793A, and −1074T, whereas variant −217G almost always occurs with −532C, −793G, and −1074G. Since allele −6A is the predominant allele in African-Americans, the AGT gene can be subdivided into two main haplotypes, −6A:−217A (AA) and −6A:−217G (AG). To understand the role of these haplotypes on hAGT gene expression and on blood pressure regulation in an in vivo situation, we have generated double transgenic mice containing human renin gene and either AA or AG haplotype of the hAGT gene using knock-in strategy at the hypoxanthine phosphoribosyltransferase locus. We show here that 1) hAGT mRNA level is increased in the liver by 60% and in the kidney by 40%; and 2) plasma AGT level is increased by ∼40%, and plasma angiotensin II level is increased by ∼50% in male double transgenic mice containing AA haplotype of the hAGT gene compared with the AG haplotype. In addition, systolic blood pressure is increased by 8 mmHg in transgenic mice containing the AA haplotype compared with the AG haplotype. This is the first report to show the effect of polymorphisms in the promoter of a human gene on its transcription in an in vivo situation that ultimately leads to an increase in blood pressure.

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In vivo mutagenicity of ethylene oxide at the hprt locus in T-lymphocytes of B6C3F1 lacI transgenic mice following inhalation exposure

Mutation Research/Genetic Toxicology and Environmental Mutagenesis ◽

10.1016/s1383-5718(97)00062-4 ◽

1997 ◽

Vol 392 (3) ◽

pp. 211-222 ◽

Cited By ~ 29

Author(s):

Vernon E Walker ◽

Susan C Sisk ◽

Patricia B Upton ◽

Brian A Wong ◽

Leslie Recio

Keyword(s):

T Lymphocytes ◽

Transgenic Mice ◽

Ethylene Oxide ◽

Inhalation Exposure ◽

Hprt Locus ◽

In Vivo Mutagenicity

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P XV.8 In vivo mutagenicity of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQX) in lacI transgenic mice

Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis ◽

10.1016/s0027-5107(97)83128-4 ◽

1997 ◽

Vol 379 (1) ◽

pp. S147 ◽

Cited By ~ 1

Author(s):

Toshiaki Itoh ◽

Takayoshi Suzuki ◽

Xue Wang ◽

Makoto Hayashi ◽

Akiyoshi Nishikawa ◽

...

Keyword(s):

Transgenic Mice ◽

In Vivo Mutagenicity

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Cardiac transgenesis with the tetracycline transactivator changes myocardial function and gene expression

Physiological Genomics ◽

10.1152/physiolgenomics.00016.2005 ◽

2005 ◽

Vol 22 (1) ◽

pp. 118-126 ◽

Cited By ~ 26

Author(s):

Diana T. McCloskey ◽

Lynne Turnbull ◽

Philip M. Swigart ◽

Alexander C. Zambon ◽

Sally Turcato ◽

...

Keyword(s):

Gene Expression ◽

Transgenic Mice ◽

Target Gene ◽

Control Group ◽

Transcription Activator ◽

Tet System ◽

Double Transgenic Mice ◽

Regulated Gene Expression

The cardiac-specific tetracycline-regulated gene expression system (tet-system) is a powerful tool using double-transgenic mice. The cardiac α-myosin heavy chain promoter (αMHC) drives lifetime expression of a tetracycline-inhibited transcription activator (tTA). Crossing αMHC-tTA mice with mice containing a tTA-responsive promoter linked to a target gene yields double-transgenic mice having tetracycline-repressed expression of the target gene in the heart. Using the tet-system, some studies use nontransgenic mice for the control group, whereas others use single-transgenic αMHC-tTA mice. However, previous studies found that high-level expression of a modified activator protein caused cardiomyopathy. Therefore, we tested whether cardiac expression of tTA was associated with altered function of αMHC-tTA mice compared with wild-type (WT) littermates. We monitored in vivo and in vitro function and gene expression profiles for myocardium from WT and αMHC-tTA mice. Compared with WT littermates, αMHC-tTA mice had a greater heart-to-body weight ratio (≈10%), ventricular dilation, and decreased ejection fraction, suggesting mild cardiomyopathy. In vitro, submaximal contractions were greater compared with WT and were associated with greater myofilament Ca2+ sensitivity. Gene expression profiling revealed that the expression of 153 genes was significantly changed by >20% when comparing αMHC-tTA with WT myocardium. These findings demonstrate that introduction of the αMHC-tTA construct causes significant effects on myocardial gene expression and major functional abnormalities in vivo and in vitro. For studies using the tet-system, these results suggest caution in the use of controls, since αMHC-tTA myocardium differs appreciably from WT. Furthermore, the results raise the possibility that the phenotype conferred by a target gene may be influenced by the modified genetic background of αMHC-tTA myocardium.

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In vivo mutagenicity of 2-amino-3,4-dimethylimidazol[4,5-f]quinoline in lac I transgenic mice (Big Blue®)

Mutation Research/Environmental Mutagenesis and Related Subjects ◽

10.1016/s0165-1161(96)90267-8 ◽

1996 ◽

Vol 359 (3) ◽

pp. 191-192

Author(s):

T. Suzuki ◽

M. Hayashi ◽

M. Ochiai ◽

T. Ushijima ◽

K. Wakabayashi ◽

...

Keyword(s):

Transgenic Mice ◽

In Vivo Mutagenicity

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Extramedullary Expansion of Hematopoietic Progenitor Cells in Interleukin (IL)-6–sIL-6R Double Transgenic Mice

Journal of Experimental Medicine ◽

10.1084/jem.185.4.755 ◽

1997 ◽

Vol 185 (4) ◽

pp. 755-766 ◽

Cited By ~ 121

Author(s):

Malte Peters ◽

Peter Schirmacher ◽

Jutta Goldschmitt ◽

Margarete Odenthal ◽

Christian Peschel ◽

...

Keyword(s):

Transgenic Mice ◽

Progenitor Cells ◽

Peripheral Blood Cell ◽

Hematopoietic Progenitor Cells ◽

Strong Increase ◽

Signal Transducer ◽

Hematopoietic Progenitor ◽

Double Transgenic Mice

Soluble cytokine receptors modulate the activity of their cognate ligands. Interleukin (IL)-6 in association with the soluble IL-6 receptor (sIL-6R) can activate cells expressing the gp130 signal transducer lacking the specific IL-6R. To investigate the function of the IL-6–sIL-6R complex in vivo and to discriminate the function of the IL-6–sIL-6R complex from the function of IL-6 alone, we have established a transgenic mouse model. Double-transgenic mice coexpressing IL-6 and sIL-6R were generated and compared with IL-6 and sIL-6R single-transgenic mice. The main phenotype found in IL-6–sIL-6R mice was a dramatic increase of extramedullary hematopoietic progenitor cells in liver and spleen but not in the bone marrow. In IL-6 single-transgenic mice and sIL-6R single-transgenic mice no such effects were observed. The high numbers of hematopoietic progenitor cells were reflected by a strong increase of peripheral blood cell numbers. Therefore, activators of the gp130 signal transducer like the IL-6–IL-6R complex may represent most powerful stimulators for extramedullary hematopoietic progenitor cells. gp130 activators may become important for the expansion of hematopoietic progenitor cells in vivo and in vitro.

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