Genes and Alcohol Consumption: Studies with Mutant Mice

PubMed Central

Mayfield, Jody; Arends, Michael A.; Harris, R. Adron; Blednov, Yuri A.

2017-01-01

In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test. PMID:27055617

Working-for-Food Behaviors: A Preclinical Study in Prader-Willi Mutant Mice.

PubMed

Lassi, Glenda; Maggi, Silvia; Balzani, Edoardo; Cosentini, Ilaria; Garcia-Garcia, Celina; Tucci, Valter

2016-11-01

Abnormal feeding behavior is one of the main symptoms of Prader-Willi syndrome (PWS). By studying a PWS mouse mutant line, which carries a paternally inherited deletion of the small nucleolar RNA 116 (Snord116), we observed significant changes in working-for-food behavioral responses at various timescales. In particular, we report that PWS mutant mice show a significant delay compared to wild-type littermate controls in responding to both hour-scale and seconds-to-minutes-scale time intervals. This timing shift in mutant mice is associated with better performance in the working-for-food task, and results in better decision making in these mutant mice. The results of our study reveal a novel aspect of the organization of feeding behavior, and advance the understanding of the interplay between the metabolic functions and cognitive mechanisms of PWS. Copyright © 2016 by the Genetics Society of America.

Enamel protein regulation and dental and periodontal physiopathology in MSX2 mutant mice.

PubMed

Molla, Muriel; Descroix, Vianney; Aïoub, Muhanad; Simon, Stéphane; Castañeda, Beatriz; Hotton, Dominique; Bolaños, Alba; Simon, Yohann; Lezot, Frédéric; Goubin, Gérard; Berdal, Ariane

2010-11-01

Signaling pathways that underlie postnatal dental and periodontal physiopathology are less studied than those of early tooth development. Members of the muscle segment homeobox gene (Msx) family encode homeoproteins that show functional redundancy during development and are known to be involved in epithelial-mesenchymal interactions that lead to crown morphogenesis and ameloblast cell differentiation. This study analyzed the MSX2 protein during mouse postnatal growth as well as in the adult. The analysis focused on enamel and periodontal defects and enamel proteins in Msx2-null mutant mice. In the epithelial lifecycle, the levels of MSX2 expression and enamel protein secretion were inversely related. Msx2+/- mice showed increased amelogenin expression, enamel thickness, and rod size. Msx2-/- mice displayed compound phenotypic characteristics of enamel defects, related to both enamel-specific gene mutations (amelogenin and enamelin) in isolated amelogenesis imperfecta, and cell-cell junction elements (laminin 5 and cytokeratin 5) in other syndromes. These effects were also related to ameloblast disappearance, which differed between incisors and molars. In Msx2-/- roots, Malassez cells formed giant islands that overexpressed amelogenin and ameloblastin that grew over months. Aberrant expression of enamel proteins is proposed to underlie the regional osteopetrosis and hyperproduction of cellular cementum. These enamel and periodontal phenotypes of Msx2 mutants constitute the first case report of structural and signaling defects associated with enamel protein overexpression in a postnatal context.

Searching for biomarkers of CDKL5 disorder: early-onset visual impairment in CDKL5 mutant mice.

PubMed

Mazziotti, Raffaele; Lupori, Leonardo; Sagona, Giulia; Gennaro, Mariangela; Della Sala, Grazia; Putignano, Elena; Pizzorusso, Tommaso

2017-06-15

CDKL5 disorder is a neurodevelopmental disorder still without a cure. Murine models of CDKL5 disorder have been recently generated raising the possibility of preclinical testing of treatments. However, unbiased, quantitative biomarkers of high translational value to monitor brain function are still missing. Moreover, the analysis of treatment is hindered by the challenge of repeatedly and non-invasively testing neuronal function. We analyzed the development of visual responses in a mouse model of CDKL5 disorder to introduce visually evoked responses as a quantitative method to assess cortical circuit function. Cortical visual responses were assessed in CDKL5 null male mice, heterozygous females, and their respective control wild-type littermates by repeated transcranial optical imaging from P27 until P32. No difference between wild-type and mutant mice was present at P25-P26 whereas defective responses appeared from P27-P28 both in heterozygous and homozygous CDKL5 mutant mice. These results were confirmed by visually evoked potentials (VEPs) recorded from the visual cortex of a different cohort. The previously imaged mice were also analyzed at P60-80 using VEPs, revealing a persistent reduction of response amplitude, reduced visual acuity and defective contrast function. The level of adult impairment was significantly correlated with the reduction in visual responses observed during development. Support vector machine showed that multi-dimensional visual assessment can be used to automatically classify mutant and wt mice with high reliability. Thus, monitoring visual responses represents a promising biomarker for preclinical and clinical studies on CDKL5 disorder. © The Author 2017. Published by Oxford University Press.

Acute Multiple Organ Failure in Adult Mice Deleted for the Developmental Regulator Wt1

PubMed Central

Chau, You-Ying; Brownstein, David; Mjoseng, Heidi; Lee, Wen-Chin; Buza-Vidas, Natalija; Nerlov, Claus; Jacobsen, Sten Eirik; Perry, Paul; Berry, Rachel; Thornburn, Anna; Sexton, David; Morton, Nik; Hohenstein, Peter; Freyer, Elisabeth; Samuel, Kay; van't Hof, Rob; Hastie, Nicholas

2011-01-01

There is much interest in the mechanisms that regulate adult tissue homeostasis and their relationship to processes governing foetal development. Mice deleted for the Wilms' tumour gene, Wt1, lack kidneys, gonads, and spleen and die at mid-gestation due to defective coronary vasculature. Wt1 is vital for maintaining the mesenchymal–epithelial balance in these tissues and is required for the epithelial-to-mesenchyme transition (EMT) that generates coronary vascular progenitors. Although Wt1 is only expressed in rare cell populations in adults including glomerular podocytes, 1% of bone marrow cells, and mesothelium, we hypothesised that this might be important for homeostasis of adult tissues; hence, we deleted the gene ubiquitously in young and adult mice. Within just a few days, the mice suffered glomerulosclerosis, atrophy of the exocrine pancreas and spleen, severe reduction in bone and fat, and failure of erythropoiesis. FACS and culture experiments showed that Wt1 has an intrinsic role in both haematopoietic and mesenchymal stem cell lineages and suggest that defects within these contribute to the phenotypes we observe. We propose that glomerulosclerosis arises in part through down regulation of nephrin, a known Wt1 target gene. Protein profiling in mutant serum showed that there was no systemic inflammatory or nutritional response in the mutant mice. However, there was a dramatic reduction in circulating IGF-1 levels, which is likely to contribute to the bone and fat phenotypes. The reduction of IGF-1 did not result from a decrease in circulating GH, and there is no apparent pathology of the pituitary and adrenal glands. These findings 1) suggest that Wt1 is a major regulator of the homeostasis of some adult tissues, through both local and systemic actions; 2) highlight the differences between foetal and adult tissue regulation; 3) point to the importance of adult mesenchyme in tissue turnover. PMID:22216009

Genes and signaling pathways involved in memory enhancement in mutant mice

PubMed Central

2014-01-01

Mutant mice have been used successfully as a tool for investigating the mechanisms of memory at multiple levels, from genes to behavior. In most cases, manipulating a gene expressed in the brain impairs cognitive functions such as memory and their underlying cellular mechanisms, including synaptic plasticity. However, a remarkable number of mutations have been shown to enhance memory in mice. Understanding how to improve a system provides valuable insights into how the system works under normal conditions, because this involves understanding what the crucial components are. Therefore, more can be learned about the basic mechanisms of memory by studying mutant mice with enhanced memory. This review will summarize the genes and signaling pathways that are altered in the mutants with enhanced memory, as well as their roles in synaptic plasticity. Finally, I will discuss how knowledge of memory-enhancing mechanisms could be used to develop treatments for cognitive disorders associated with impaired plasticity. PMID:24894914

The pathogenicity of thymidine kinase-deficient mutants of herpes simplex virus in mice.

PubMed

Field, H J; Wildy, P

1978-10-01

The pathogenicity for mice of two mutants of herpes simplex virus (type 1 and type 2), which fail to induce thymidine kinase, were compared with their respective parent strains. The mutants were much less virulent than the parents following either intracerebral or peripheral inoculation. The replication of the virus at the site of inoculation and its progression into the nervous system were studied. Following a very large inoculum in the ear, the type 1 mutant was found to establish a latent infection in the cervical dorsal root ganglia. Mice inoculated intracerebrally with small doses of the mutant viruses were solidly immune to challenge with lethal doses of the parent strain.

Enamel Protein Regulation and Dental and Periodontal Physiopathology in Msx2 Mutant Mice

PubMed Central

Molla, Muriel; Descroix, Vianney; Aïoub, Muhanad; Simon, Stéphane; Castañeda, Beatriz; Hotton, Dominique; Bolaños, Alba; Simon, Yohann; Lezot, Frédéric; Goubin, Gérard; Berdal, Ariane

2010-01-01

Signaling pathways that underlie postnatal dental and periodontal physiopathology are less studied than those of early tooth development. Members of the muscle segment homeobox gene (Msx) family encode homeoproteins that show functional redundancy during development and are known to be involved in epithelial-mesenchymal interactions that lead to crown morphogenesis and ameloblast cell differentiation. This study analyzed the MSX2 protein during mouse postnatal growth as well as in the adult. The analysis focused on enamel and periodontal defects and enamel proteins in Msx2-null mutant mice. In the epithelial lifecycle, the levels of MSX2 expression and enamel protein secretion were inversely related. Msx2+/− mice showed increased amelogenin expression, enamel thickness, and rod size. Msx2−/− mice displayed compound phenotypic characteristics of enamel defects, related to both enamel-specific gene mutations (amelogenin and enamelin) in isolated amelogenesis imperfecta, and cell-cell junction elements (laminin 5 and cytokeratin 5) in other syndromes. These effects were also related to ameloblast disappearance, which differed between incisors and molars. In Msx2−/− roots, Malassez cells formed giant islands that overexpressed amelogenin and ameloblastin that grew over months. Aberrant expression of enamel proteins is proposed to underlie the regional osteopetrosis and hyperproduction of cellular cementum. These enamel and periodontal phenotypes of Msx2 mutants constitute the first case report of structural and signaling defects associated with enamel protein overexpression in a postnatal context. PMID:20934968

The pathogenicity of thymidine kinase-deficient mutants of herpes simplex virus in mice.

PubMed Central

Field, H. J.; Wildy, P.

1978-01-01

The pathogenicity for mice of two mutants of herpes simplex virus (type 1 and type 2), which fail to induce thymidine kinase, were compared with their respective parent strains. The mutants were much less virulent than the parents following either intracerebral or peripheral inoculation. The replication of the virus at the site of inoculation and its progression into the nervous system were studied. Following a very large inoculum in the ear, the type 1 mutant was found to establish a latent infection in the cervical dorsal root ganglia. Mice inoculated intracerebrally with small doses of the mutant viruses were solidly immune to challenge with lethal doses of the parent strain. PMID:212476

Mice with ablated adult brain neurogenesis are not impaired in antidepressant response to chronic fluoxetine.

PubMed

Jedynak, Paulina; Kos, Tomasz; Sandi, Carmen; Kaczmarek, Leszek; Filipkowski, Robert K

2014-09-01

The neurogenesis hypothesis of major depression has two main facets. One states that the illness results from decreased neurogenesis while the other claims that the very functioning of antidepressants depends on increased neurogenesis. In order to verify the latter, we have used cyclin D2 knockout mice (cD2 KO mice), known to have virtually no adult brain neurogenesis, and we demonstrate that these mice successfully respond to chronic fluoxetine. After unpredictable chronic mild stress, mutant mice showed depression-like behavior in forced swim test, which was eliminated with chronic fluoxetine treatment, despite its lack of impact on adult hippocampal neurogenesis in cD2 KO mice. Our results suggest that new neurons are not indispensable for the action of antidepressants such as fluoxetine. Using forced swim test and tail suspension test, we also did not observe depression-like behavior in control cD2 KO mice, which argues against the link between decreased adult brain neurogenesis and major depression. Copyright © 2014 Elsevier Ltd. All rights reserved.

Structural abnormalities of corpus callosum and cortical axonal tracts accompanied by decreased anxiety-like behavior and lowered sociability in spock3- mutant mice.

PubMed

Yamamoto, Ayako; Uchiyama, Koji; Nara, Tomoka; Nishimura, Naomichi; Hayasaka, Michiko; Hanaoka, Kazunori; Yamamoto, Tatsuro

2014-01-01

Spock3/Testican-3 is a nervous system-expressed heparan sulfate proteoglycan belonging to a subgroup of the BM-40/SPARC/osteonectin family, the role of which in brain development is unclear. Because Spock1, a member of the Spock family, inhibits their attachment to substrates and the neurite outgrowth of cultured neuronal cells, Spock3 is also thought to be similarly involved in the neuronal development. In the present study, we established a Spock3-mutant mouse harboring a deletion extending from the presumptive upstream regulatory region to exon 4 of the Spock3 locus and performed histological and behavioral studies on these mutant mice. In wild-type (WT) mice, all Spock members were clearly expressed during brain development. In adults, intense Spock1 and Spock2 expressions were observed throughout the entire brain; whereas, Spock3 expression was no longer visible except in the thalamic nuclei. Thus, Spock3 expression is mostly confined to the developmental stage of the brain. In adult mutant mice, the cells of all cortical layers were swollen. The corpus callosum was narrowed around the central region along the rostral-caudal axis and many small spaces were observed without myelin sheaths throughout the entire corpus callosum. In addition, the cortical input and output fibers did not form into thick bundled fibers as well as the WT counterparts did. Moreover, a subpopulation of corticospinal axonal fibers penetrated into the dorsal striatum with moderately altered orientations. Consistent with these modifications of brain structures, the mutant mice exhibited decreased anxiety-like behavior and lowered sociability. Together, these results demonstrate that Spock3 plays an important role in the formation or maintenance of major neuronal structures in the brain. © 2014 S. Karger AG, Basel.

Anti-H-Y responses of H-2b mutant mice.

PubMed

Simpson, E; Gordon, R D; Chandler, P R; Bailey, D

1978-10-01

Two strains of H-2b mutant mice, H-2ba and H-2bf, in which the mutational event took place at H-2K, make anti-H-Y cytotoxic T cell responses which are H-2-restricted, Db-associated and indistinguishable in target cell specificity from those of H-2b mice. Thus, alteration of the H-2K molecule affects neither the Ir gene controlling the response, nor the associative antigen. On the other hand, one H-2Db mutant strain, H-2bo, although it makes a good anti-H-Y cytotoxic response, shows target cell specificity restricted to its own Dbo antigen(s), and neither H-2b, H-2ba or H-2bf anti-H-Y cytotoxic cells kill H-2bo male target cells. Thus, the alteration of the H-2Db molecule does not affect the Ir gene of H-2b mice, but it does alter the H-2Db-associative antigen.

Mutant SOD1 in cell types other than motor neurons and oligodendrocytes accelerates onset of disease in ALS mice

PubMed Central

Yamanaka, Koji; Boillee, Severine; Roberts, Elizabeth A.; Garcia, Michael L.; McAlonis-Downes, Melissa; Mikse, Oliver R.; Cleveland, Don W.; Goldstein, Lawrence S. B.

2008-01-01

Dominant mutations in ubiquitously expressed superoxide dismutase (SOD1) cause familial ALS by provoking premature death of adult motor neurons. To test whether mutant damage to cell types beyond motor neurons is required for the onset of motor neuron disease, we generated chimeric mice in which all motor neurons and oligodendrocytes expressed mutant SOD1 at a level sufficient to cause fatal, early-onset motor neuron disease when expressed ubiquitously, but did so in a cellular environment containing variable numbers of non-mutant, non-motor neurons. Despite high-level mutant expression within 100% of motor neurons and oligodendrocytes, in most of these chimeras, the presence of WT non-motor neurons substantially delayed onset of motor neuron degeneration, increasing disease-free life by 50%. Disease onset is therefore non-cell autonomous, and mutant SOD1 damage within cell types other than motor neurons and oligodendrocytes is a central contributor to initiation of motor neuron degeneration. PMID:18492803

Phenotype detection in morphological mutant mice using deformation features.

PubMed

Roy, Sharmili; Liang, Xi; Kitamoto, Asanobu; Tamura, Masaru; Shiroishi, Toshihiko; Brown, Michael S

2013-01-01

Large-scale global efforts are underway to knockout each of the approximately 25,000 mouse genes and interpret their roles in shaping the mammalian embryo. Given the tremendous amount of data generated by imaging mutated prenatal mice, high-throughput image analysis systems are inevitable to characterize mammalian development and diseases. Current state-of-the-art computational systems offer only differential volumetric analysis of pre-defined anatomical structures between various gene-knockout mice strains. For subtle anatomical phenotypes, embryo phenotyping still relies on the laborious histological techniques that are clearly unsuitable in such big data environment. This paper presents a system that automatically detects known phenotypes and assists in discovering novel phenotypes in muCT images of mutant mice. Deformation features obtained from non-linear registration of mutant embryo to a normal consensus average image are extracted and analyzed to compute phenotypic and candidate phenotypic areas. The presented system is evaluated using C57BL/10 embryo images. All cases of ventricular septum defect and polydactyly, well-known to be present in this strain, are successfully detected. The system predicts potential phenotypic areas in the liver that are under active histological evaluation for possible phenotype of this mouse line.

Disrupting Jagged1-Notch signaling impairs spatial memory formation in adult mice.

PubMed

Sargin, Derya; Botly, Leigh C P; Higgs, Gemma; Marsolais, Alexander; Frankland, Paul W; Egan, Sean E; Josselyn, Sheena A

2013-07-01

It is well-known that Notch signaling plays a critical role in brain development and growing evidence implicates this signaling pathway in adult synaptic plasticity and memory formation. The Notch1 receptor is activated by two subclasses of ligands, Delta-like (including Dll1 and Dll4) and Jagged (including Jag1 and Jag2). Ligand-induced Notch1 receptor signaling is modulated by a family of Fringe proteins, including Lunatic fringe (Lfng). Although Dll1, Jag1 and Lfng are critical regulators of Notch signaling, their relative contribution to memory formation in the adult brain is unknown. To investigate the roles of these important components of Notch signaling in memory formation, we examined spatial and fear memory formation in adult mice with reduced expression of Dll1, Jag1, Lfng and Dll1 plus Lfng. We also examined motor activity, anxiety-like behavior and sensorimotor gating using the acoustic startle response in these mice. Of the lines of mutant mice tested, we found that only mice with reduced Jag1 expression (mice heterozygous for a null mutation in Jag1, Jag1(+/-)) showed a selective impairment in spatial memory formation. Importantly, all other behavior including open field activity, conditioned fear memory (both context and discrete cue), acoustic startle response and prepulse inhibition, was normal in this line of mice. These results provide the first in vivo evidence that Jag1-Notch signaling is critical for memory formation in the adult brain. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

GH and IGF1: roles in energy metabolism of long-living GH mutant mice.

PubMed

Brown-Borg, Holly M; Bartke, Andrzej

2012-06-01

Of the multiple theories to explain exceptional longevity, the most robust of these has centered on the reduction of three anabolic protein hormones, growth hormone (GH), insulin-like growth factor, and insulin. GH mutant mice live 50% longer and exhibit significant differences in several aspects of energy metabolism as compared with wild-type mice. Mitochondrial metabolism is upregulated in the absence of GH, whereas in GH transgenic mice and dwarf mice treated with GH, multiple aspects of these pathways are suppressed. Core body temperature is markedly lower in dwarf mice, yet whole-body metabolism, as measured by indirect calorimetry, is surprisingly higher in Ames dwarf and Ghr-/- mice compared with normal controls. Elevated adiponectin, a key antiinflammatory cytokine, is also very likely to contribute to longevity in these mice. Thus, several important components related to energy metabolism are altered in GH mutant mice, and these differences are likely critical in aging processes and life-span extension.

Calreticulin mutants in mice induce an MPL-dependent thrombocytosis with frequent progression to myelofibrosis.

PubMed

Marty, Caroline; Pecquet, Christian; Nivarthi, Harini; El-Khoury, Mira; Chachoua, Ilyas; Tulliez, Micheline; Villeval, Jean-Luc; Raslova, Hana; Kralovics, Robert; Constantinescu, Stefan N; Plo, Isabelle; Vainchenker, William

2016-03-10

Frameshift mutations in the calreticulin (CALR) gene are seen in about 30% of essential thrombocythemia and myelofibrosis patients. To address the contribution of the CALR mutants to the pathogenesis of myeloproliferative neoplasms, we engrafted lethally irradiated recipient mice with bone marrow cells transduced with retroviruses expressing these mutants. In contrast to wild-type CALR, CALRdel52 (type I) and, to a lesser extent, CALRins5 (type II) induced thrombocytosis due to a megakaryocyte (MK) hyperplasia. Disease was transplantable into secondary recipients. After 6 months, CALRdel52-, in contrast to rare CALRins5-, transduced mice developed a myelofibrosis associated with a splenomegaly and a marked osteosclerosis. Monitoring of virus-transduced populations indicated that CALRdel52 leads to expansion at earlier stages of hematopoiesis than CALRins5. However, both mutants still specifically amplified the MK lineage and platelet production. Moreover, a mutant deleted of the entire exon 9 (CALRdelex9) did not induce a disease, suggesting that the oncogenic property of CALR mutants was related to the new C-terminus peptide. To understand how the CALR mutants target the MK lineage, we used a cell-line model and demonstrated that the CALR mutants, but not CALRdelex9, specifically activate the thrombopoietin (TPO) receptor (MPL) to induce constitutive activation of Janus kinase 2 and signal transducer and activator of transcription 5/3/1. We confirmed in c-mpl- and tpo-deficient mice that expression of Mpl, but not of Tpo, was essential for the CALR mutants to induce thrombocytosis in vivo, although Tpo contributes to disease penetrance. Thus, CALR mutants are sufficient to induce thrombocytosis through MPL activation. © 2016 by The American Society of Hematology.

mPeriod2 Brdm1 and other single Period mutant mice have normal food anticipatory activity.

PubMed

Pendergast, Julie S; Wendroth, Robert H; Stenner, Rio C; Keil, Charles D; Yamazaki, Shin

2017-11-14

Animals anticipate the timing of food availability via the food-entrainable oscillator (FEO). The anatomical location and timekeeping mechanism of the FEO are unknown. Several studies showed the circadian gene, Period 2, is critical for FEO timekeeping. However, other studies concluded that canonical circadian genes are not essential for FEO timekeeping. In this study, we re-examined the effects of the Per2 Brdm1 mutation on food entrainment using methods that have revealed robust food anticipatory activity in other mutant lines. We examined food anticipatory activity, which is the output of the FEO, in single Period mutant mice. Single Per1, Per2, and Per3 mutant mice had robust food anticipatory activity during restricted feeding. In addition, we found that two different lines of Per2 mutant mice (ldc and Brdm1) anticipated restricted food availability. To determine if FEO timekeeping persisted in the absence of the food cue, we assessed activity during fasting. Food anticipatory (wheel-running) activity in all Period mutant mice was also robust during food deprivation. Together, our studies demonstrate that the Period genes are not necessary for the expression of food anticipatory activity.

Fear-related behaviors in Lurcher mutant mice exposed to a predator.

PubMed

Lorivel, T; Roy, V; Hilber, P

2014-11-01

The Lurcher mutant mice are characterized by massive cerebellar cortex degeneration. Besides their motor and cognitive disturbances, they exhibit both exaggerated blood corticosterone (CORT) level surge and behavioral disinhibition when confronted to anxiogenic conditions (i.e. to a potential threat). In this study, we assessed if such physiological and behavioral hyperactivity was also detectable in a fear-eliciting situation (actual threat). For this purpose, the behaviors and CORT level elevations in Lurcher mice were compared with those of littermate controls in the predator exposure test: mice were exposed either to a rat (exposure) or to a brief wave of the experimenter's hand (sham exposure). While the basal CORT concentrations (24 h before testing) were not significantly different between mice of both genotypes, the post-exposure ones were higher in Lurcher than in control mice whatever the condition of the experimental design (exposure or sham exposure). Predator exposure did not provoke significant increase of CORT levels whatever the genotype. On the contrary, our data clearly showed that fear-related behaviors of cerebellar mutants facing a real threat were exacerbated in comparison to those of control mice. These results suggest that the cerebellar cortex not only participates to fear conditioning and anxiety but also actively contributes to the modulation of the innate fear-related behaviors. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Overexpression of mutant HSP27 causes axonal neuropathy in mice.

PubMed

Lee, Jinho; Jung, Sung-Chul; Joo, Jaesoon; Choi, Yu-Ri; Moon, Hyo Won; Kwak, Geon; Yeo, Ha Kyung; Lee, Ji-Su; Ahn, Hye-Jee; Jung, Namhee; Hwang, Sunhee; Rheey, Jingeun; Woo, So-Youn; Kim, Ji Yon; Hong, Young Bin; Choi, Byung-Ok

2015-06-19

Mutations in heat shock 27 kDa protein 1 (HSP27 or HSPB1) cause distal hereditary motor neuropathy (dHMN) or Charcot-Marie-Tooth disease type 2 F (CMT2F) according to unknown factors. Mutant HSP27 proteins affect axonal transport by reducing acetylated tubulin. We generated a transgenic mouse model overexpressing HSP27-S135F mutant protein driven by Cytomegalovirus (CMV) immediate early promoter. The mouse phenotype was similar to dHMN patients in that they exhibit motor neuropathy. To determine the phenotypic aberration of transgenic mice, behavior test, magnetic resonance imaging (MRI), electrophysiological study, and pathology were performed. Rotarod test showed that founder mice exhibited lowered motor performance. MRI also revealed marked fatty infiltration in the anterior and posterior compartments at calf level. Electrophysiologically, compound muscle action potential (CMAP) but not motor nerve conduction velocity (MNCV) was reduced in the transgenic mice. Toluidine staining with semi-thin section of sciatic nerve showed the ratio of large myelinated axon fiber was reduced, which might cause reduced locomotion in the transgenic mice. Electron microscopy also revealed abundant aberrant myelination. Immunohistochemically, neuronal dysfunctions included elevated level of phosphorylated neurofilament and reduced level of acetylated tubulin in the sural nerve of transgenic mice. There was no additional phenotype besides motor neuronal defects. Overexpression of HSP27-S135F protein causes peripheral neuropathy. The mouse model can be applied to future development of therapeutic strategies for dHMN or CMT2F.

Sucrose intake and fasting glucose levels in 5-HT(1A) and 5-HT(1B) receptor mutant mice.

PubMed

Bechtholt, Anita J; Smith, Karen; Gaughan, Stephanie; Lucki, Irwin

2008-03-18

Serotonin (5-HT)(1A) and 5-HT(1B) receptors have been implicated in the incidence and treatment of depression in part through the examination of animals lacking these receptors. Although these receptors have been repeatedly implicated in ingestive behavior there is little information about how 5-HT(1A) and 5-HT(1B) receptor mutant mice react to solutions of varying palatability. In the present experiment male and female 5-HT(1A) and 5-HT(1B) mutant and wild-type mice were presented with increasing concentrations of sucrose using a two-bottle choice procedure. In addition fasting blood glucose levels were assessed. Both male and female 5-HT(1B) mutant mice drank more sucrose than WT mice but also consumed more water. Female, but not male, 5-HT(1A) mutant mice similarly showed increased sucrose consumption, but did not demonstrate increased consumption of water. In addition, the pattern of increased sucrose consumption over genotype and sex was related to fasting blood glucose concentrations such that levels in male 5-HT(1B) mutant mice were reduced relative to wild-type and 5-HT(1A) mutant males, but similar to those of females. The findings in 5-HT(1B) mutant mice emphasize the role of the 5-HT(1B) receptor in regulating ingestive behavior, whereas female sex hormones and 5-HT(1A) receptors may interact to alter sucrose consumption in 5-HT(1A) mutant mice. In addition, these findings may have implications for the role of these receptors in the incidence and treatment of depression since the intake of sucrose has been used as an index of anhedonia in animal models of depression and antidepressant efficacy.

Spermatogenesis arrest caused by conditional deletion of Hsp90α in adult mice

PubMed Central

Kajiwara, Chiaki; Kondo, Shiho; Uda, Shizuha; Dai, Lei; Ichiyanagi, Tomoko; Chiba, Tomoki; Ishido, Satoshi; Koji, Takehiko; Udono, Heiichiro

2012-01-01

Summary It is controversial whether a functional androgen receptor (AR) on germ cells, including spermatogonia, is essential for their development into sperm and, thus, initiation and maintenance of spermatogenesis. It was recently shown that many spermatocytes underwent apoptosis in the testes of Hsp90α KO mice. We had generated Hsp90α KO mice independently and confirmed this phenotype. However, the important question of whether Hsp90α is required to maintain spermatogenesis in adult mice in which testicular maturation is already completed could not be addressed using these conventional KO mice. To answer this question, we generated a tamoxifen-inducible deletion mutant of Hsp90α and found that conditional deletion of Hsp90α in adult mice caused even more severe apoptosis in germ cells beyond the pachytene stage, leading to complete arrest of spermatogenesis and testicular atrophy. Importantly, immunohistochemical analysis revealed that AR expression in WT testis was more evident in spermatogonia than in spermatocytes, whereas its expression was aberrant and ectopic in Hsp90α KO testis, raising the possibility that an AR abnormality in primordial germ cells is involved in spermatogenesis arrest in the Hsp90α KO mice. Our results suggest that the AR, specifically chaperoned by Hsp90α in spermatogonia, is critical for maintenance of established spermatogenesis and for survival of spermatocytes in adult testis, in addition to setting the first wave of spermatogenesis before puberty. PMID:23213375

Serine 421 regulates mutant huntingtin toxicity and clearance in mice

PubMed Central

Kratter, Ian H.; Zahed, Hengameh; Lau, Alice; Daub, Aaron C.; Weiberth, Kurt F.; Gu, Xiaofeng; Humbert, Sandrine; Yang, X. William; Osmand, Alex; Steffan, Joan S.; Masliah, Eliezer

2016-01-01

Huntington’s disease (HD) is a progressive, adult-onset neurodegenerative disease caused by a polyglutamine (polyQ) expansion in the N-terminal region of the protein huntingtin (HTT). There are no cures or disease-modifying therapies for HD. HTT has a highly conserved Akt phosphorylation site at serine 421, and prior work in HD models found that phosphorylation at S421 (S421-P) diminishes the toxicity of mutant HTT (mHTT) fragments in neuronal cultures. However, whether S421-P affects the toxicity of mHTT in vivo remains unknown. In this work, we used murine models to investigate the role of S421-P in HTT-induced neurodegeneration. Specifically, we mutated the human mHTT gene within a BAC to express either an aspartic acid or an alanine at position 421, mimicking tonic phosphorylation (mHTT-S421D mice) or preventing phosphorylation (mHTT-S421A mice), respectively. Mimicking HTT phosphorylation strongly ameliorated mHTT-induced behavioral dysfunction and striatal neurodegeneration, whereas neuronal dysfunction persisted when S421 phosphorylation was blocked. We found that S421 phosphorylation mitigates neurodegeneration by increasing proteasome-dependent turnover of mHTT and reducing the presence of a toxic mHTT conformer. These data indicate that S421 is a potent modifier of mHTT toxicity and offer in vivo validation for S421 as a therapeutic target in HD. PMID:27525439

Synapsin I and Synapsin II regulate neurogenesis in the dentate gyrus of adult mice

PubMed Central

Barbieri, Raffaella; Contestabile, Andrea; Ciardo, Maria Grazia; Forte, Nicola; Marte, Antonella; Baldelli, Pietro; Benfenati, Fabio; Onofri, Franco

2018-01-01

Adult neurogenesis is emerging as an important player in brain functions and homeostasis, while impaired or altered adult neurogenesis has been associated with a number of neuropsychiatric diseases, such as depression and epilepsy. Here we investigated the possibility that synapsins (Syns) I and II, beyond their known functions in developing and mature neurons, also play a role in adult neurogenesis. We performed a systematic evaluation of the distinct stages of neurogenesis in the hippocampal dentate gyrus of Syn I and Syn II knockout (KO) mice, before (2-months-old) and after (6-months-old) the appearance of the epileptic phenotype. We found that Syns I and II play an important role in the regulation of adult neurogenesis. In juvenile mice, Syn II deletion was associated with a specific decrease in the proliferation of neuronal progenitors, whereas Syn I deletion impaired the survival of newborn neurons. These defects were reverted after the appearance of the epileptic phenotype, with Syn I KO and Syn II KO mice exhibiting significant increases in survival and proliferation, respectively. Interestingly, long-term potentiation dependent on newborn neurons was present in both juvenile Syn mutants while, at later ages, it was only preserved in Syn II KO mice that also displayed an increased expression of brain-derived neurotrophic factor. This study suggests that Syns I and II play a role in adult neurogenesis and the defects in neurogenesis associated with Syn deletion may contribute to the alterations of cognitive functions observed in Syn-deficient mice. PMID:29721159

Synapsin I and Synapsin II regulate neurogenesis in the dentate gyrus of adult mice.

PubMed

Barbieri, Raffaella; Contestabile, Andrea; Ciardo, Maria Grazia; Forte, Nicola; Marte, Antonella; Baldelli, Pietro; Benfenati, Fabio; Onofri, Franco

2018-04-10

Adult neurogenesis is emerging as an important player in brain functions and homeostasis, while impaired or altered adult neurogenesis has been associated with a number of neuropsychiatric diseases, such as depression and epilepsy. Here we investigated the possibility that synapsins (Syns) I and II, beyond their known functions in developing and mature neurons, also play a role in adult neurogenesis. We performed a systematic evaluation of the distinct stages of neurogenesis in the hippocampal dentate gyrus of Syn I and Syn II knockout (KO) mice, before (2-months-old) and after (6-months-old) the appearance of the epileptic phenotype. We found that Syns I and II play an important role in the regulation of adult neurogenesis. In juvenile mice, Syn II deletion was associated with a specific decrease in the proliferation of neuronal progenitors, whereas Syn I deletion impaired the survival of newborn neurons. These defects were reverted after the appearance of the epileptic phenotype, with Syn I KO and Syn II KO mice exhibiting significant increases in survival and proliferation, respectively. Interestingly, long-term potentiation dependent on newborn neurons was present in both juvenile Syn mutants while, at later ages, it was only preserved in Syn II KO mice that also displayed an increased expression of brain-derived neurotrophic factor. This study suggests that Syns I and II play a role in adult neurogenesis and the defects in neurogenesis associated with Syn deletion may contribute to the alterations of cognitive functions observed in Syn-deficient mice.

Atf3 mutant mice show reduced axon regeneration and impaired regeneration-associated gene induction after peripheral nerve injury

PubMed Central

Gey, Manuel; Wanner, Renate; Schilling, Corinna; Pedro, Maria T.; Sinske, Daniela

2016-01-01

Axon injury in the peripheral nervous system (PNS) induces a regeneration-associated gene (RAG) response. Atf3 (activating transcription factor 3) is such a RAG and ATF3's transcriptional activity might induce ‘effector’ RAGs (e.g. small proline rich protein 1a (Sprr1a), Galanin (Gal), growth-associated protein 43 (Gap43)) facilitating peripheral axon regeneration. We provide a first analysis of Atf3 mouse mutants in peripheral nerve regeneration. In Atf3 mutant mice, facial nerve regeneration and neurite outgrowth of adult ATF3-deficient primary dorsal root ganglia neurons was decreased. Using genome-wide transcriptomics, we identified a neuropeptide-encoding RAG cluster (vasoactive intestinal peptide (Vip), Ngf, Grp, Gal, Pacap) regulated by ATF3. Exogenous administration of neuropeptides enhanced neurite growth of Atf3 mutant mice suggesting that these molecules might be effector RAGs of ATF3's pro-regenerative function. In addition to the induction of growth-promoting molecules, we present data that ATF3 suppresses growth-inhibiting molecules such as chemokine (C-C motif) ligand 2. In summary, we show a pro-regenerative ATF3 function during PNS nerve regeneration involving transcriptional activation of a neuropeptide-encoding RAG cluster. ATF3 is a general injury-inducible factor, therefore ATF3-mediated mechanisms identified herein might apply to other cell and injury types. PMID:27581653

Cp/Heph mutant mice have iron-induced neurodegeneration diminished by deferiprone

PubMed Central

Zhao, Liangliang; Hadziahmetovic, Majda; Wang, Chenguang; Xu, Xueying; Song, Ying; Jinnah, H.A.; Wodzinska, Jolanta; Iacovelli, Jared; Wolkow, Natalie; Krajacic, Predrag; Weissberger, Alyssa Cwanger; Connelly, John; Spino, Michael; Lee, Michael K.; Connor, James; Giasson, Benoit; Harris, Z. Leah; Dunaief, Joshua L.

2016-01-01

Brain iron accumulates in several neurodegenerative diseases and can cause oxidative damage, but mechanisms of brain iron homeostasis are incompletely understood. Patients with mutations in the cellular iron-exporting ferroxidase ceruloplasmin (Cp) have brain iron accumulation causing neurodegeneration. Here, we assessed the brains of mice with combined mutation of Cp and its homolog hephaestin. Compared to single mutants, brain iron accumulation was accelerated in double mutants in the cerebellum, substantia nigra, and hippocampus. Iron accumulated within glia, while neurons were iron deficient. There was loss of both neurons and glia. Mice developed ataxia and tremor, and most died by 9 months. Treatment with the oral iron chelator deferiprone diminished brain iron levels, protected against neuron loss, and extended lifespan. Ferroxidases play important, partially overlapping roles in brain iron homeostasis by facilitating iron export from glia, making iron available to neurons. PMID:26303407

An improved Red/ET recombineering system and mouse ES cells culture conditions for the generation of targeted mutant mice.

PubMed

Kumagai, Katsuyoshi; Takanashi, Masakatsu; Ohno, Shin-Ichiro; Kuroda, Masahiko; Sudo, Katsuko

2017-05-03

Targeted mutant mice generated on a C57BL/6 background are powerful tools for analysis of the biological functions of genes, and gene targeting technologies using mouse embryonic stem (ES) cells have been used to generate such mice. Recently, a bacterial artificial chromosome (BAC) recombineering system was established for the construction of targeting vectors. However, gene retrieval from BACs for the generation of gene targeting vectors using this system remains difficult. Even when construction of a gene targeting vector is successful, the efficiency of production of targeted mutant mice from ES cells derived from C57BL/6 mice are poor. Therefore, in this study, we first improved the strategy for the retrieval of genes from BACs and their transfer into a DT-A plasmid, for the generation of gene targeting vectors using the BAC recombineering system. Then, we attempted to generate targeted mutant mice from ES cell lines derived from C57BL/6 mice, by culturing in serum-free medium. In conclusion, we established an improved strategy for the efficient generation of targeted mutant mice on a C57BL/6 background, which are useful for the in vivo analysis of gene functions and regulation.

Etiology of a genetically complex seizure disorder in Celf4 mutant mice

PubMed Central

Wagnon, Jacy L.; Mahaffey, Connie L.; Sun, Wenzhi; Yang, Yan; Chao, Hsiao-Tuan; Frankel, Wayne N.

2011-01-01

Mice deficient for the gene encoding the RNA-binding protein CELF4 (CUGBP, ELAV-like family member 4) have a complex seizure phenotype that includes both convulsive and non-convulsive seizures, depending upon gene dosage and strain background, modeling genetically complex epilepsy. Invertebrate CELF is associated with translational control in fruit fly ovary epithelium and with neurogenesis and neuronal function in the nematode. Mammalian CELF4 is expressed widely during early development, but is restricted to the central nervous system in adult. To better understand the etiology of the seizure disorder of Celf4 deficient mice, we studied seizure incidence with spatial and temporal conditional knockout Celf4 alleles. For convulsive seizure phenotypes, it is sufficient to delete Celf4 in adulthood at seven weeks of age. This timing is in contrast to absence-like non-convulsive seizures, which require deletion before the end of the first postnatal week. Interestingly, selective deletion of Celf4 from cerebral cortex and hippocampus excitatory neurons, but not from inhibitory neurons, is sufficient to lower seizure threshold and to promote spontaneous convulsions. Correspondingly, Celf4 deficient mice have altered excitatory, but not inhibitory, neurotransmission as measured by patch-clamp recordings of cortical layer V pyramidal neurons. Finally, immunostaining in conjunction with an inhibitory neuron-specific reporter shows that CELF4 is expressed predominantly in excitatory neurons. Our results suggest that CELF4 plays a specific role in regulating excitatory neurotransmission. We posit that altered excitatory neurotransmission resulting from Celf4 deficiency underlies the complex seizure disorder in Celf4 mutant mice. PMID:21745337

Ablation of huntingtin in adult neurons is nondeleterious but its depletion in young mice causes acute pancreatitis

PubMed Central

Wang, Guohao; Liu, Xudong; Gaertig, Marta A.; Li, Shihua; Li, Xiao-Jiang

2016-01-01

The Huntington’s disease (HD) protein, huntingtin (HTT), is essential for early development. Because suppressing the expression of mutant HTT is an important approach to treat the disease, we must first understand the normal function of Htt in adults versus younger animals. Using inducible Htt knockout mice, we found that Htt depletion does not lead to adult neurodegeneration or animal death at >4 mo of age, which was also verified by selectively depleting Htt in neurons. On the other hand, young Htt KO mice die at 2 mo of age of acute pancreatitis due to the degeneration of pancreatic acinar cells. Importantly, Htt interacts with the trypsin inhibitor, serine protease inhibitor Kazal-type 3 (Spink3), to inhibit activation of digestive enzymes in acinar cells in young mice, and transgenic HTT can rescue the early death of Htt KO mice. These findings point out age- and cell type-dependent vital functions of Htt and the safety of knocking down neuronal Htt expression in adult brains as a treatment. PMID:26951659

Targeted inactivation of the mouse locus encoding coagulation factor XIII-A: hemostatic abnormalities in mutant mice and characterization of the coagulation deficit.

PubMed

Lauer, Peter; Metzner, Hubert J; Zettlmeissl, Gerd; Li, Meng; Smith, Austin G; Lathe, Richard; Dickneite, Gerhard

2002-12-01

Blood coagulation factor XIII (FXIII) promotes cross-linking of fibrin during blood coagulation; impaired clot stabilization in human genetic deficiency is associated with marked pathologies of major clinical impact, including bleeding symptoms and deficient wound healing. To investigate the role of FXIII we employed homologous recombination to generate a targeted deletion of the inferred exon 7 of the FXIII-A gene. FXIII transglutaminase activity in plasma was reduced to about 50% in mice heterozygous for the mutant allele, and was abolished in homozygous null mice. Plasma fibrin gamma-dimerization was also indetectable in the homozygous deficient animals, confirming the absence of activatable FXIII. Homozygous mutant mice were fertile, although reproduction was impaired. Bleeding episodes, hematothorax, hematoperitoneum and subcutaneous hemorrhage in mutant mice were associated with reduced survival. Arrest of tail-tip bleeding in FXIII-A deficient mice was markedly and significantly delayed; replacement of mutant mice with human plasma FXIII (Fibrogammin P) restored bleeding time to within the normal range. Thrombelastography (TEG) experiments demonstrated impaired clot stabilization in FXIII-A mutant mice, replacement with human FXIII led to dose-dependent TEG normalization. The mutant mice thus reiterate some key features of the human genetic disorder: they will be valuable in assessing the role of FXIII in other associated pathologies and the development of new therapies.

The effect of cerebellar transplantation and enforced physical activity on motor skills and spatial learning in adult Lurcher mutant mice.

PubMed

Cendelín, Jan; Korelusová, Ivana; Vozeh, Frantisek

2009-03-01

Lurcher mutant mice represent a model of olivocerebellar degeneration. They are used to investigate cerebellar functions, consequences of cerebellar degeneration and methods of therapy influencing them. The aim of the work was to assess the effect of foetal cerebellar graft transplantation, repeated enforced physical activity and the combination of both these types of treatment on motor skills, spontaneous motor activity and spatial learning ability in adult B6CBA Lurcher mice. Foetal cerebellar grafts were applied into the cerebellum of Lurchers in the form of solid tissue pieces. Enforced motor activity was realised through rotarod training. Motor functions were examined using bar, ladder and rotarod tests. Spatial learning was tested in the Morris water maze. Spontaneous motor activity in the open field was observed. The presence of the graft was examined histologically. Enforced physical activity led to moderate improvement of some motor skills and to a significant amelioration of spatial learning ability in Lurchers. The transplantation of cerebellar tissue did not influence motor functions significantly but led to an improvement of spatial learning ability. Mutual advancement of the effects of both types of treatment was not observed. Spontaneous motor activity was influenced neither by physical activity nor by the transplantation. Physical activity did not influence the graft survival and development. Because nerve sprouting and cell migration from the graft to the host cerebellum was poor, the functional effects of the graft should be explained with regard to its trophic influence rather than with any involvement of the grafted cells into neural circuitries.

Diabetes and exocrine pancreatic insufficiency in E2F1/E2F2 double-mutant mice.

PubMed

Iglesias, Ainhoa; Murga, Matilde; Laresgoiti, Usua; Skoudy, Anouchka; Bernales, Irantzu; Fullaondo, Asier; Moreno, Bernardino; Lloreta, José; Field, Seth J; Real, Francisco X; Zubiaga, Ana M

2004-05-01

E2F transcription factors are thought to be key regulators of cell growth control. Here we use mutant mouse strains to investigate the function of E2F1 and E2F2 in vivo. E2F1/E2F2 compound-mutant mice develop nonautoimmune insulin-deficient diabetes and exocrine pancreatic dysfunction characterized by endocrine and exocrine cell dysplasia, a reduction in the number and size of acini and islets, and their replacement by ductal structures and adipose tissue. Mutant pancreatic cells exhibit increased rates of DNA replication but also of apoptosis, resulting in severe pancreatic atrophy. The expression of genes involved in DNA replication and cell cycle control was upregulated in the E2F1/E2F2 compound-mutant pancreas, suggesting that their expression is repressed by E2F1/E2F2 activities and that the inappropriate cell cycle found in the mutant pancreas is likely the result of the deregulated expression of these genes. Interestingly, the expression of ductal cell and adipocyte differentiation marker genes was also upregulated, whereas expression of pancreatic cell marker genes were downregulated. These results suggest that E2F1/E2F2 activity negatively controls growth of mature pancreatic cells and is necessary for the maintenance of differentiated pancreatic phenotypes in the adult.

Hypervitaminosis D and premature aging: lessons learned from Fgf23 and Klotho mutant mice.

PubMed

Razzaque, Mohammed S; Lanske, Beate

2006-07-01

The essential role of low levels of vitamin D during aging is well documented. However, possible effects of high levels of vitamin D on the aging process are not yet clear. Recent in vivo genetic-manipulation studies have shown increased serum level of vitamin D and altered mineral-ion homeostasis in mice that lack either fibroblast growth factor 23 (Fgf23) or klotho (Kl) genes. These mice develop identical phenotypes consistent with premature aging. Elimination or reduction of vitamin-D activity from Fgf23 and Kl mutant mice, either by dietary restriction or genetic manipulation could rescue premature aging-like features and ectopic calcifications, resulting in prolonged survival of both mutants. Such in vivo experimental studies indicated that excessive vitamin-D activity and altered mineral-ion homeostasis could accelerate the aging process.

Increased Tau Phosphorylation and Tau Truncation, and Decreased Synaptophysin Levels in Mutant BRI2/Tau Transgenic Mice

PubMed Central

Garringer, Holly J.; Murrell, Jill; Sammeta, Neeraja; Gnezda, Anita; Ghetti, Bernardino; Vidal, Ruben

2013-01-01

Familial Danish dementia (FDD) is an autosomal dominant neurodegenerative disease caused by a 10-nucleotide duplication-insertion in the BRI2 gene. FDD is clinically characterized by loss of vision, hearing impairment, cerebellar ataxia and dementia. The main neuropathologic findings in FDD are the deposition of Danish amyloid (ADan) and the presence of neurofibrillary tangles (NFTs). Here we investigated tau accumulation and truncation in double transgenic (Tg-FDD-Tau) mice generated by crossing transgenic mice expressing human Danish mutant BRI2 (Tg-FDD) with mice expressing human 4-repeat mutant Tau-P301S (Tg-Tau). Compared to Tg-Tau mice, we observed a significant enhancement of tau deposition in Tg-FDD-Tau mice. In addition, a significant increase in tau cleaved at aspartic acid (Asp) 421 was observed in Tg-FDD-Tau mice. Tg-FDD-Tau mice also showed a significant decrease in synaptophysin levels, occurring before widespread deposition of fibrillar ADan and tau can be observed. Thus, the presence of soluble ADan/mutant BRI2 can lead to significant changes in tau metabolism and synaptic dysfunction. Our data provide new in vivo insights into the pathogenesis of FDD and the pathogenic pathway(s) by which amyloidogenic peptides, regardless of their primary amino acid sequence, can cause neurodegeneration. PMID:23418567

Increased tau phosphorylation and tau truncation, and decreased synaptophysin levels in mutant BRI2/tau transgenic mice.

PubMed

Garringer, Holly J; Murrell, Jill; Sammeta, Neeraja; Gnezda, Anita; Ghetti, Bernardino; Vidal, Ruben

2013-01-01

Familial Danish dementia (FDD) is an autosomal dominant neurodegenerative disease caused by a 10-nucleotide duplication-insertion in the BRI(2) gene. FDD is clinically characterized by loss of vision, hearing impairment, cerebellar ataxia and dementia. The main neuropathologic findings in FDD are the deposition of Danish amyloid (ADan) and the presence of neurofibrillary tangles (NFTs). Here we investigated tau accumulation and truncation in double transgenic (Tg-FDD-Tau) mice generated by crossing transgenic mice expressing human Danish mutant BRI(2) (Tg-FDD) with mice expressing human 4-repeat mutant Tau-P301S (Tg-Tau). Compared to Tg-Tau mice, we observed a significant enhancement of tau deposition in Tg-FDD-Tau mice. In addition, a significant increase in tau cleaved at aspartic acid (Asp) 421 was observed in Tg-FDD-Tau mice. Tg-FDD-Tau mice also showed a significant decrease in synaptophysin levels, occurring before widespread deposition of fibrillar ADan and tau can be observed. Thus, the presence of soluble ADan/mutant BRI(2) can lead to significant changes in tau metabolism and synaptic dysfunction. Our data provide new in vivo insights into the pathogenesis of FDD and the pathogenic pathway(s) by which amyloidogenic peptides, regardless of their primary amino acid sequence, can cause neurodegeneration.

[Accumulation of the bvg- Bordetella pertussis a virulent mutants in the process of experimental whooping cough in mice].

PubMed

Medkova, A Iu; Siniashina, L N; Rumiantseva, Iu P; Voronina, O L; Kunda, M S; Karataev, G I

2013-01-01

The duration of the persistence and dynamics of accumulation of insertion bvg- Bordetella pertussis mutants were studied in lungs of laboratory mice after intranasal and intravenous challenge by virulent bacteria of the causative agent of whooping cough. The capability of the virulent B. pertussis bacteria to long-term persistence in the body of mice was tested. Using the real-time PCR approximately hundred genome equivalents of the B. pertussis DNA were detected in lungs of mice in two months after infection regardless of the way of challenge. Using the bacterial test bacteria were identified during only four weeks after challenge. Bvg- B. pertussis avirulent mutants were accumulated for the infection time. The percentage of the avirulent bacteria in the B. pertussis population reached 50% in 7-9 weeks after challenge. The obtained results show that the laboratory mice can be used for study of the B. pertussis insertion mutant formation dynamics in vivo and confirm the hypothesis about insertional bvg- B. pertussis virulent mutants accumulation during development of pertussis infection in human.

eIF4E/Fmr1 double mutant mice display cognitive impairment in addition to ASD-like behaviors.

PubMed

Huynh, Thu N; Shah, Manan; Koo, So Yeon; Faraud, Kirsten S; Santini, Emanuela; Klann, Eric

2015-11-01

Autism spectrum disorder (ASD) is a group of heritable disorders with complex and unclear etiology. Classic ASD symptoms include social interaction and communication deficits as well as restricted, repetitive behaviors. In addition, ASD is often comorbid with intellectual disability. Fragile X syndrome (FXS) is the leading genetic cause of ASD, and is the most commonly inherited form of intellectual disability. Several mouse models of ASD and FXS exist, however the intellectual disability observed in ASD patients is not well modeled in mice. Using the Fmr1 knockout mouse and the eIF4E transgenic mouse, two previously characterized mouse models of fragile X syndrome and ASD, respectively, we generated the eIF4E/Fmr1 double mutant mouse. Our study shows that the eIF4E/Fmr1 double mutant mice display classic ASD behaviors, as well as cognitive dysfunction. Importantly, the learning impairments displayed by the double mutant mice spanned multiple cognitive tasks. Moreover, the eIF4E/Fmr1 double mutant mice display increased levels of basal protein synthesis. The results of our study suggest that the eIF4E/Fmr1 double mutant mouse may be a reliable model to study cognitive dysfunction in the context of ASD. Copyright © 2015 Elsevier Inc. All rights reserved.

Cortico-striatal synaptic defects and OCD-like behaviors in SAPAP3 mutant mice

PubMed Central

Welch, Jeffrey M.; Lu, Jing; Rodriguiz, Ramona M.; Trotta, Nicholas C.; Peca, Joao; Ding, Jin-Dong; Feliciano, Catia; Chen, Meng; Adams, J. Paige; Luo, Jianhong; Dudek, Serena M.; Weinberg, Richard J.; Calakos, Nicole; Wetsel, William C.; Feng, Guoping

2008-01-01

Obsessive-compulsive disorder (OCD) is an anxiety-spectrum disorder characterized by persistent intrusive thoughts (obsessions) and repetitive actions (compulsions). Dysfunction of cortico-striato-thalamo-cortical circuitry is implicated in OCD, though the underlying pathogenic mechanisms are unknown. SAP90/PSD95-associated protein 3 (SAPAP3) is a postsynaptic scaffolding protein at excitatory synapses that is highly expressed in the striatum. Here we show that mice with genetic deletion of SAPAP3 exhibit increased anxiety and compulsive grooming behavior leading to facial hair loss and skin lesions; both behaviors are alleviated by a selective serotonin reuptake inhibitor. Electrophysiological, structural, and biochemical studies of SAPAP3 mutant mice reveal defects in cortico-striatal synapses. Furthermore, lentiviral-mediated selective expression of SAPAP3 in the striatum rescues the synaptic and behavioral defects of SAPAP3 mutant mice. These findings demonstrate a critical role for SAPAP3 at cortico-striatal synapses and emphasize the importance of cortico-striatal circuitry in OCD-like behaviors. PMID:17713528

An Early Postnatal Oxytocin Treatment Prevents Social and Learning Deficits in Adult Mice Deficient for Magel2, a Gene Involved in Prader-Willi Syndrome and Autism.

PubMed

Meziane, Hamid; Schaller, Fabienne; Bauer, Sylvian; Villard, Claude; Matarazzo, Valery; Riet, Fabrice; Guillon, Gilles; Lafitte, Daniel; Desarmenien, Michel G; Tauber, Maithé; Muscatelli, Françoise

2015-07-15

Mutations of MAGEL2 have been reported in patients presenting with autism, and loss of MAGEL2 is also associated with Prader-Willi syndrome, a neurodevelopmental genetic disorder. This study aimed to determine the behavioral phenotype of Magel2-deficient adult mice, to characterize the central oxytocin (OT) system of these mutant mice, and to test the curative effect of a peripheral OT treatment just after birth. We assessed the social and cognitive behavior of Magel2-deficient mice, analyzed the OT system of mutant mice treated or not by a postnatal administration of OT, and determined the effect of this treatment on the brain. Magel2 inactivation induces a deficit in social recognition and social interaction and a reduced learning ability in adult male mice. In these mice, we reveal anatomical and functional modifications of the OT system and show that these defects change from birth to adulthood. Daily administration of OT in the first postnatal week was sufficient to prevent deficits in social behavior and learning abilities in adult mutant male mice. We show that this OT treatment partly restores a normal OT system. Thus, we report that an alteration of the OT system around birth has long-term consequences on behavior and on cognition. Importantly, an acute OT treatment of Magel2-deficient pups has a curative effect. Our study reveals that OT plays a crucial role in setting social behaviors during a period just after birth. An early OT treatment in this critical period could be a novel therapeutic approach for the treatment of neurodevelopmental disorders such as Prader-Willi syndrome and autism. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Abnormalities in brain structure and behavior in GSK-3alpha mutant mice

PubMed Central

2009-01-01

Background Glycogen synthase kinase-3 (GSK-3) is a widely expressed and highly conserved serine/threonine protein kinase encoded by two genes that generate two related proteins: GSK-3α and GSK-3β. Mice lacking a functional GSK-3α gene were engineered in our laboratory; they are viable and display insulin sensitivity. In this study, we have characterized brain functions of GSK-3α KO mice by using a well-established battery of behavioral tests together with neurochemical and neuroanatomical analysis. Results Similar to the previously described behaviours of GSK-3β+/-mice, GSK-3α mutants display decreased exploratory activity, decreased immobility time and reduced aggressive behavior. However, genetic inactivation of the GSK-3α gene was associated with: decreased locomotion and impaired motor coordination, increased grooming activity, loss of social motivation and novelty; enhanced sensorimotor gating and impaired associated memory and coordination. GSK-3α KO mice exhibited a deficit in fear conditioning, however memory formation as assessed by a passive avoidance test was normal, suggesting that the animals are sensitized for active avoidance of a highly aversive stimulus in the fear-conditioning paradigm. Changes in cerebellar structure and function were observed in mutant mice along with a significant decrease of the number and size of Purkinje cells. Conclusion Taken together, these data support a role for the GSK-3α gene in CNS functioning and possible involvement in the development of psychiatric disorders. PMID:19925672

Impaired Spermatogenesis, Muscle, and Erythrocyte Function in U12 Intron Splicing-Defective Zrsr1 Mutant Mice.

PubMed

Horiuchi, Keiko; Perez-Cerezales, Serafín; Papasaikas, Panagiotis; Ramos-Ibeas, Priscila; López-Cardona, Angela Patricia; Laguna-Barraza, Ricardo; Fonseca Balvís, Noelia; Pericuesta, Eva; Fernández-González, Raul; Planells, Benjamín; Viera, Alberto; Suja, Jose Angel; Ross, Pablo Juan; Alén, Francisco; Orio, Laura; Rodriguez de Fonseca, Fernando; Pintado, Belén; Valcárcel, Juan; Gutiérrez-Adán, Alfonso

2018-04-03

The U2AF35-like ZRSR1 has been implicated in the recognition of 3' splice site during spliceosome assembly, but ZRSR1 knockout mice do not show abnormal phenotypes. To analyze ZRSR1 function and its precise role in RNA splicing, we generated ZRSR1 mutant mice containing truncating mutations within its RNA-recognition motif. Homozygous mutant mice exhibited severe defects in erythrocytes, muscle stretch, and spermatogenesis, along with germ cell sloughing and apoptosis, ultimately leading to azoospermia and male sterility. Testis RNA sequencing (RNA-seq) analyses revealed increased intron retention of both U2- and U12-type introns, including U12-type intron events in genes with key functions in spermatogenesis and spermatid development. Affected U2 introns were commonly found flanking U12 introns, suggesting functional cross-talk between the two spliceosomes. The splicing and tissue defects observed in mutant mice attributed to ZRSR1 loss of function suggest a physiological role for this factor in U12 intron splicing. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Further studies on cortical tangential migration in wild type and Pax-6 mutant mice.

PubMed

Jiménez, D; López-Mascaraque, L; de Carlos, J A; Valverde, F

2002-01-01

In this study we present new data concerning the tangential migration from the medial and lateral ganglionic eminences (MGE and LGE) to the cerebral cortex during development. We have used Calbindin as a useful marker to follow the itinerary of tangential migratory cells during early developmental stages in wild-type and Pax-6 homozygous mutant mice. In the wild-type mice, at early developmental stages, migrating cells advance through the intermediate zone (IZ) and preplate (PP). At more advanced stages, migrating cells were present in the subplate (SP) and cortical plate (CP) to reach the entire developing cerebral cortex. We found that, in the homozygous mutant mice (Pax-6(Sey-Neu)/Pax-6(Sey-Neu)), this tangential migration is severely affected at early developmental stages: migrating cells were absent in the IZ, which were only found some days later, suggesting that in the mutant mice, there is a temporal delay in tangential migration. We have also defined some possible mechanisms to explain certain migratory routes from the basal telencephalon to the cerebral cortex. We describe the existence of two factors, which we consider to be essential for the normal migration; the first one is the cell adhesion molecule PSA-NCAM, whose role in other migratory systems is well known. The second factor is Robo-2, whose expression delimits a channel for the passage of migratory cells from the basal telencephalon to the cerebral cortex.

Ectopic Mineralization and Conductive Hearing Loss in Enpp1asj Mutant Mice, a New Model for Otitis Media and Tympanosclerosis.

PubMed

Tian, Cong; Harris, Belinda S; Johnson, Kenneth R

2016-01-01

Otitis media (OM), inflammation of the middle ear, is a common cause of hearing loss in children and in patients with many different syndromic diseases. Studies of the human population and mouse models have revealed that OM is a multifactorial disease with many environmental and genetic contributing factors. Here, we report on otitis media-related hearing loss in asj (ages with stiffened joints) mutant mice, which bear a point mutation in the Enpp1 gene. Auditory-evoked brainstem response (ABR) measurements revealed that around 90% of the mutant mice (Enpp1asj/asj) tested had moderate to severe hearing impairment in at least one ear. The ABR thresholds were variable and generally elevated with age. We found otitis media with effusion (OME) in all of the hearing-impaired Enpp1asj/asj mice by anatomic and histological examinations. The volume and inflammatory cell content of the effusion varied among the asj mutant mice, but all mutants exhibited a thickened middle ear epithelium with fibrous polyps and more mucin-secreting goblet cells than controls. Other abnormalities observed in the Enpp1 mutant mice include over-ossification at the round window ridge, thickened and over-calcified stapedial artery, fusion of malleus and incus, and white patches on the inside of tympanic membrane, some of which are typical symptoms of tympanosclerosis. An excessive yellow discharge was detected in the outer ear canal of older asj mutant mice, with 100% penetrance by 5 months of age, and contributes to the progressive nature of the hearing loss. This is the first report of hearing loss and ear pathology associated with an Enpp1 mutation in mice. The Enpp1asj mutant mouse provides a new animal model for studying tympanosclerotic otitis and otitis media with effusion, and also provides a specific model for the hearing loss recently reported to be associated with human ENPP1 mutations causing generalized arterial calcification of infancy and hypophosphatemic rickets.

Ectopic Mineralization and Conductive Hearing Loss in Enpp1asj Mutant Mice, a New Model for Otitis Media and Tympanosclerosis

PubMed Central

Tian, Cong; Harris, Belinda S.; Johnson, Kenneth R.

2016-01-01

Otitis media (OM), inflammation of the middle ear, is a common cause of hearing loss in children and in patients with many different syndromic diseases. Studies of the human population and mouse models have revealed that OM is a multifactorial disease with many environmental and genetic contributing factors. Here, we report on otitis media-related hearing loss in asj (ages with stiffened joints) mutant mice, which bear a point mutation in the Enpp1 gene. Auditory-evoked brainstem response (ABR) measurements revealed that around 90% of the mutant mice (Enpp1asj/asj) tested had moderate to severe hearing impairment in at least one ear. The ABR thresholds were variable and generally elevated with age. We found otitis media with effusion (OME) in all of the hearing-impaired Enpp1asj/asj mice by anatomic and histological examinations. The volume and inflammatory cell content of the effusion varied among the asj mutant mice, but all mutants exhibited a thickened middle ear epithelium with fibrous polyps and more mucin-secreting goblet cells than controls. Other abnormalities observed in the Enpp1 mutant mice include over-ossification at the round window ridge, thickened and over-calcified stapedial artery, fusion of malleus and incus, and white patches on the inside of tympanic membrane, some of which are typical symptoms of tympanosclerosis. An excessive yellow discharge was detected in the outer ear canal of older asj mutant mice, with 100% penetrance by 5 months of age, and contributes to the progressive nature of the hearing loss. This is the first report of hearing loss and ear pathology associated with an Enpp1 mutation in mice. The Enpp1asj mutant mouse provides a new animal model for studying tympanosclerotic otitis and otitis media with effusion, and also provides a specific model for the hearing loss recently reported to be associated with human ENPP1 mutations causing generalized arterial calcification of infancy and hypophosphatemic rickets. PMID:27959908

Schwann cell hyperplasia and tumors in transgenic mice expressing a naturally occurring mutant NF2 protein

PubMed Central

Giovannini, Marco; Robanus-Maandag, Els; Niwa-Kawakita, Michiko; van der Valk, Martin; Woodruff, James M.; Goutebroze, Laurence; Mérel, Philippe; Berns, Anton; Thomas, Gilles

1999-01-01

Specific mutations in some tumor suppressor genes such as p53 can act in a dominant fashion. We tested whether this mechanism may also apply for the neurofibromatosis type-2 gene (NF2) which, when mutated, leads to schwannoma development. Transgenic mice were generated that express, in Schwann cells, mutant NF2 proteins prototypic of natural mutants observed in humans. Mice expressing a NF2 protein with an interstitial deletion in the amino-terminal domain showed high prevalence of Schwann cell-derived tumors and Schwann cell hyperplasia, whereas those expressing a carboxy-terminally truncated protein were normal. Our results indicate that a subset of mutant NF2 alleles observed in patients may encode products with dominant properties when overexpressed in specific cell lineages. PMID:10215625

Optimizing catecholaminergic polymorphic ventricular tachycardia therapy in calsequestrin-mutant mice

PubMed Central

Katz, Guy; Khoury, Assad; Kurtzwald, Efrat; Hochhauser, Edith; Porat, Eyal; Shainberg, Asher; Seidman, Jonathan G.; Seidman, Christine E.; Lorber, Abraham; Eldar, Michael; Arad, Michael

2014-01-01

BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal arrhythmia provoked by physical or emotional stress and mediated by spontaneous Ca2+ release and delayed after-depolarizations. Beta-adrenergic blockers are the therapy of choice but fail to control arrhythmia in up to 50% of patients. OBJECTIVE To optimize antiarrhythmic therapy in recessively inherited CPVT caused by calsequestrin (CASQ2) mutations. METHODS Murine heart rhythm telemetry was obtained at rest, during treadmill exercise, and after injection of epinephrine. The protocol was repeated after injection of different antiarrhythmic drugs. Results were then validated in human patients. RESULTS Adult CASQ2 mutant mice had complex ventricular arrhythmia at rest and developed bidirectional and polymorphic ventricular tachycardia on exertion. Class I antiarrhythmic agents (procainamide, lidocaine, flecainide) were ineffective in controlling arrhythmia. Propranolol and sotalol attenuated arrhythmia at rest but failed to prevent VT during sympathetic stimulation. The calcium channel blocker verapamil showed a dose-dependent protection against CPVT. Verapamil was more effective than the dihydropyridine L-type Ca2+ channel blocker nifedipine, and its activity was markedly enhanced when combined with propranolol. Human patients homozygous for CASQ2D307H mutation, remaining symptomatic despite chronic β-blocker therapy, underwent exercise testing according to the Bruce protocol with continuous electrocardiogram recording. Verapamil was combined with propranolol at maximum tolerated doses. Adding verapamil attenuated ventricular arrhythmia and prolonged exercise duration in five of 11 patients. CONCLUSION Verapamil is highly effective against catecholamine-induced arrhythmia in mice with CASQ2 mutations and may potentiate the antiarrhythmic activity of β-blockers in humans with CPVT2. PMID:20620233

Serotonin signaling in the brain of adult female mice is required for sexual preference

PubMed Central

Zhang, Shasha; Liu, Yan; Rao, Yi

2013-01-01

A role for serotonin in male sexual preference was recently uncovered by our finding that male mutant mice lacking serotonin have lost sexual preference. Here we show that female mouse mutants lacking either central serotonergic neurons or serotonin prefer female over male genital odors when given a choice, and displayed increased female–female mounting when presented either with a choice of a male and a female target or only with a female target. Pharmacological manipulations and genetic rescue experiments showed that serotonin is required in adults. Behavioral changes caused by deficient serotonergic signaling were not due to changes in plasma concentrations of sex hormones. We demonstrate that a genetic manipulation reverses sexual preference without involving sex hormones. Our results indicate that serotonin controls sexual preference. PMID:23716677

Motor hypertonia and lack of locomotor coordination in mutant mice lacking DSCAM.

PubMed

Lemieux, Maxime; Laflamme, Olivier D; Thiry, Louise; Boulanger-Piette, Antoine; Frenette, Jérôme; Bretzner, Frédéric

2016-03-01

Down syndrome cell adherence molecule (DSCAM) contributes to the normal establishment and maintenance of neural circuits. Whereas there is abundant literature regarding the role of DSCAM in the neural patterning of the mammalian retina, less is known about motor circuits. Recently, DSCAM mutation has been shown to impair bilateral motor coordination during respiration, thus causing death at birth. DSCAM mutants that survive through adulthood display a lack of locomotor endurance and coordination in the rotarod test, thus suggesting that the DSCAM mutation impairs motor control. We investigated the motor and locomotor functions of DSCAM(2J) mutant mice through a combination of anatomical, kinematic, force, and electromyographic recordings. With respect to wild-type mice, DSCAM(2J) mice displayed a longer swing phase with a limb hyperflexion at the expense of a shorter stance phase during locomotion. Furthermore, electromyographic activity in the flexor and extensor muscles was increased and coactivated over 20% of the step cycle over a wide range of walking speeds. In contrast to wild-type mice, which used lateral walk and trot at walking speed, DSCAM(2J) mice used preferentially less coordinated gaits, such as out-of-phase walk and pace. The neuromuscular junction and the contractile properties of muscles, as well as their muscle spindles, were normal, and no signs of motor rigidity or spasticity were observed during passive limb movements. Our study demonstrates that the DSCAM mutation induces dystonic hypertonia and a disruption of locomotor gaits. Copyright © 2016 the American Physiological Society.

Tissue-specific and time-dependent clonal expansion of ENU-induced mutant cells in gpt delta mice.

PubMed

Nakayama, Takafumi; Sawai, Tomoko; Masuda, Ikuko; Kaneko, Shinya; Yamauchi, Kazumi; Blyth, Benjamin J; Shimada, Yoshiya; Tachibana, Akira; Kakinuma, Shizuko

2017-10-01

DNA mutations play a crucial role in the origins of cancer, and the clonal expansion of mutant cells is one of the fundamental steps in multistage carcinogenesis. In this study, we correlated tumor incidence in B6C3F1 mice during the period after exposure to N-ethyl-N-nitrosourea (ENU) with the persistence of ENU-induced mutant clones in transgenic gpt delta B6C3F1 mice. The induced gpt mutations afforded no selective advantage in the mouse cells and could be distinguished by a mutational spectrum that is characteristic of ENU treatment. The gpt mutations were passengers of the mutant cell of origin and its daughter cells and thus could be used as neutral markers of clones that arose and persisted in the tissues. Female B6C3F1 mice exposed for 1 month to 200 ppm ENU in the drinking water developed early thymic lymphomas and late liver and lung tumors. To assay gpt mutations, we sampled the thymus, liver, lung, and small intestine of female gpt delta mice at 3 days, 4 weeks, and 8 weeks after the end of ENU exposure. Our results reveal that, in all four tissues, the ENU-induced gpt mutations persisted for weeks after the end of mutagen exposure. Clonal expansion of mutant cells was observed in the thymus and small intestine, with the thymus showing larger clone sizes. These results indicate that the clearance of mutant cells and the potential for clonal expansion during normal tissue growth depends on tissue type and that these factors may affect the sensitivity of different tissues to carcinogenesis. Environ. Mol. Mutagen. 58:592-606, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Seizure susceptibility of neuropeptide-Y null mutant mice in amygdala kindling and chemical-induced seizure models.

PubMed

Shannon, Harlan E; Yang, Lijuan

2004-01-01

Neuropeptide Y (NPY) administered exogenously is anticonvulsant, and, NPY null mutant mice are more susceptible to kainate-induced seizures. In order to better understand the potential role of NPY in epileptogenesis, the present studies investigated the development of amygdala kindling, post-kindling seizure thresholds, and anticonvulsant effects of carbamazepine and levetiracetam in 129S6/SvEv NPY(+/+) and NPY(-/-) mice. In addition, susceptibility to pilocarpine- and kainate-induced seizures was compared in NPY(+/+) and (-/-) mice. The rate of amygdala kindling development did not differ in the NPY(-/-) and NPY(+/+) mice either when kindling stimuli were presented once daily for at least 20 days, or, 12 times daily for 2 days. However, during kindling development, the NPY(-/-) mice had higher seizure severity scores and longer afterdischarge durations than the NPY(+/+) mice. Post-kindling, the NPY(-/-) mice had markedly lower afterdischarge thresholds and longer afterdischarge durations than NPY (+/+) mice. Carbamazepine and levetiracetam increased the seizure thresholds of both NPY (-/-) and (+/+) mice. In addition, NPY (-/-) mice had lower thresholds for both kainate- and pilocarpine-induced seizures. The present results in amygdala kindling and chemical seizure models suggest that NPY may play a more prominent role in determining seizure thresholds and severity of seizures than in events leading to epileptogenesis. In addition, a lack of NPY does not appear to confer drug-resistance in that carbamazepine and levetiracetam were anticonvulsant in both wild type (WT) and NPY null mutant mice.

Modeled changes of cerebellar activity in mutant mice are predictive of their learning impairments

NASA Astrophysics Data System (ADS)

Badura, Aleksandra; Clopath, Claudia; Schonewille, Martijn; de Zeeuw, Chris I.

2016-11-01

Translating neuronal activity to measurable behavioral changes has been a long-standing goal of systems neuroscience. Recently, we have developed a model of phase-reversal learning of the vestibulo-ocular reflex, a well-established, cerebellar-dependent task. The model, comprising both the cerebellar cortex and vestibular nuclei, reproduces behavioral data and accounts for the changes in neural activity during learning in wild type mice. Here, we used our model to predict Purkinje cell spiking as well as behavior before and after learning of five different lines of mutant mice with distinct cell-specific alterations of the cerebellar cortical circuitry. We tested these predictions by obtaining electrophysiological data depicting changes in neuronal spiking. We show that our data is largely consistent with the model predictions for simple spike modulation of Purkinje cells and concomitant behavioral learning in four of the mutants. In addition, our model accurately predicts a shift in simple spike activity in a mutant mouse with a brainstem specific mutation. This combination of electrophysiological and computational techniques opens a possibility of predicting behavioral impairments from neural activity.

Modeled changes of cerebellar activity in mutant mice are predictive of their learning impairments

PubMed Central

Badura, Aleksandra; Clopath, Claudia; Schonewille, Martijn; De Zeeuw, Chris I.

2016-01-01

Translating neuronal activity to measurable behavioral changes has been a long-standing goal of systems neuroscience. Recently, we have developed a model of phase-reversal learning of the vestibulo-ocular reflex, a well-established, cerebellar-dependent task. The model, comprising both the cerebellar cortex and vestibular nuclei, reproduces behavioral data and accounts for the changes in neural activity during learning in wild type mice. Here, we used our model to predict Purkinje cell spiking as well as behavior before and after learning of five different lines of mutant mice with distinct cell-specific alterations of the cerebellar cortical circuitry. We tested these predictions by obtaining electrophysiological data depicting changes in neuronal spiking. We show that our data is largely consistent with the model predictions for simple spike modulation of Purkinje cells and concomitant behavioral learning in four of the mutants. In addition, our model accurately predicts a shift in simple spike activity in a mutant mouse with a brainstem specific mutation. This combination of electrophysiological and computational techniques opens a possibility of predicting behavioral impairments from neural activity. PMID:27805050

Deficient plasticity in the primary visual cortex of alpha-calcium/calmodulin-dependent protein kinase II mutant mice.

PubMed

Gordon, J A; Cioffi, D; Silva, A J; Stryker, M P

1996-09-01

The recent characterization of plasticity in the mouse visual cortex permits the use of mutant mice to investigate the cellular mechanisms underlying activity-dependent development. As calcium-dependent signaling pathways have been implicated in neuronal plasticity, we examined visual cortical plasticity in mice lacking the alpha-isoform of calcium/calmodulin-dependent protein kinase II (alpha CaMKII). In wild-type mice, brief occlusion of vision in one eye during a critical period reduces responses in the visual cortex. In half of the alpha CaMKII-deficient mice, visual cortical responses developed normally, but visual cortical plasticity was greatly diminished. After intensive training, spatial learning in the Morris water maze was severely impaired in a similar fraction of mutant animals. These data indicate that loss of alpha CaMKII results in a severe but variable defect in neuronal plasticity.

Tissue-specific oxidative stress and loss of mitochondria in CoQ-deficient Pdss2 mutant mice.

PubMed

Quinzii, Catarina M; Garone, Caterina; Emmanuele, Valentina; Tadesse, Saba; Krishna, Sindu; Dorado, Beatriz; Hirano, Michio

2013-02-01

Primary human CoQ(10) deficiencies are clinically heterogeneous diseases caused by mutations in PDSS2 and other genes required for CoQ(10) biosynthesis. Our in vitro studies of PDSS2 mutant fibroblasts, with <20% CoQ(10) of control cells, revealed reduced activity of CoQ(10)-dependent complex II+III and ATP synthesis, without amplification of reactive oxygen species (ROS), markers of oxidative damage, or antioxidant defenses. In contrast, COQ2 and ADCK3 mutant fibroblasts, with 30-50% CoQ(10) of controls, showed milder bioenergetic defects but significantly increased ROS and oxidation of lipids and proteins. We hypothesized that absence of oxidative stress markers and cell death in PDSS2 mutant fibroblasts were due to the extreme severity of CoQ(10) deficiency. Here, we have investigated in vivo effects of Pdss2 deficiency in affected and unaffected organs of CBA/Pdss2(kd/kd) mice at presymptomatic, phenotypic-onset, and end-stages of the disease. Although Pdss2 mutant mice manifest widespread CoQ(9) deficiency and mitochondrial respiratory chain abnormalities, only affected organs show increased ROS production, oxidative stress, mitochondrial DNA depletion, and reduced citrate synthase activity, an index of mitochondrial mass. Our data indicate that kidney-specific loss of mitochondria triggered by oxidative stress may be the cause of renal failure in Pdss2(kd/kd) mice.

Fibroblast growth factor receptor two (FGFR2) regulates uterine epithelial integrity and fertility in mice.

PubMed

Filant, Justyna; DeMayo, Franco J; Pru, James K; Lydon, John P; Spencer, Thomas E

2014-01-01

Fibroblast growth factors (FGFs) and their receptors (FGFRs) regulate luminal epithelial (LE) cell proliferation in the adult mouse uterus. This study tested the hypothesis that FGFR2 has a biological role in postnatal development and function of the uterus by conditionally deleting Fgfr2 after birth using progesterone receptor (Pgr)-Cre mice. Adult Fgfr2 mutant female mice were initially subfertile and became infertile with increasing parity. No defects in uterine gland development were observed in conditional Fgfr2 mutant mice. In the adult, Fgfr2 mutant mice possessed a histologically normal reproductive tract with the exception of the uterus. The LE of the Fgfr2 mutant uterus was stratified, but no obvious histological differences were observed in the glandular epithelium, stroma, or myometrium. Within the stratified LE, cuboidal basal cells were present and positive for basal cell markers (KRT14 and TRP63). Nulliparous bred Fgfr2 mutants contained normal numbers of blastocysts on Day 3.5 postmating, but the number of embryo implantation sites was substantially reduced on Day 5.5 postmating. These results support the idea that loss of FGFR2 in the uterus after birth alters its development, resulting in LE stratification and peri-implantation pregnancy loss.

Improvement in motor performance of Weaver mutant mice following lesions of the cerebellum.

PubMed

Grüsser, C; Grüsser-Cornehls, U

1998-12-01

In Weaver mutants (B6CBA wv/wv) cerebellar granule cells degenerate almost completely postnatally. A partial loss of Purkinje cells (PC) and a degeneration of dopaminergic cells in the substantia nigra have also been found. Weaver mice suffer from striking motor symptoms, including difficulty in walking without toppling over. In an attempt to influence the poor motor performance, the cerebellum in young animals was removed, thus eliminating the faulty output of surviving PCs, demonstrated electrophysiologically. Unoperated Weaver, lesioned wildtypes and one sham mouse were used as controls. Before and after operation, a battery of behavioural tests was performed. In Weaver mice, tumbling to the side (t) and the relation of t to the motor activity (k) while traversing an open-field matrix, (t/k), improved considerably, as did manoeuvring on a slanted wire mesh, but keeping balance on a wooden bench did not to the same degree. Locomotor activity alone improved in some animals. In wildtypes no significant changes occurred after operation, with the exception of a strong reduction in locomotor activity. The experiments demonstrate that the motor performance in Weaver mutant mice benefits from removal of their cerebellum.

Mutant calreticulin knockin mice develop thrombocytosis and myelofibrosis without a stem cell self-renewal advantage.

PubMed

Li, Juan; Prins, Daniel; Park, Hyun Jung; Grinfeld, Jacob; Gonzalez-Arias, Carlos; Loughran, Stephen; Dovey, Oliver M; Klampfl, Thorsten; Bennett, Cavan; Hamilton, Tina L; Pask, Dean C; Sneade, Rachel; Williams, Matthew; Aungier, Juliet; Ghevaert, Cedric; Vassiliou, George S; Kent, David G; Green, Anthony R

2018-02-08

Somatic mutations in the endoplasmic reticulum chaperone calreticulin (CALR) are detected in approximately 40% of patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF). Multiple different mutations have been reported, but all result in a +1-bp frameshift and generate a novel protein C terminus. In this study, we generated a conditional mouse knockin model of the most common CALR mutation, a 52-bp deletion. The mutant novel human C-terminal sequence is integrated into the otherwise intact mouse CALR gene and results in mutant CALR expression under the control of the endogenous mouse locus. CALR del/+ mice develop a transplantable ET-like disease with marked thrombocytosis, which is associated with increased and morphologically abnormal megakaryocytes and increased numbers of phenotypically defined hematopoietic stem cells (HSCs). Homozygous CALR del/del mice developed extreme thrombocytosis accompanied by features of MF, including leukocytosis, reduced hematocrit, splenomegaly, and increased bone marrow reticulin. CALR del/+ HSCs were more proliferative in vitro, but neither CALR del/+ nor CALR del/del displayed a competitive transplantation advantage in primary or secondary recipient mice. These results demonstrate the consequences of heterozygous and homozygous CALR mutations and provide a powerful model for dissecting the pathogenesis of CALR-mutant ET and PMF. © 2018 by The American Society of Hematology.

Mutant Huntingtin Gene-Dose Impacts on Aggregate Deposition, DARPP32 Expression and Neuroinflammation in HdhQ150 Mice

PubMed Central

Young, Douglas; Mayer, Franziska; Vidotto, Nella; Schweizer, Tatjana; Berth, Ramon; Abramowski, Dorothee; Shimshek, Derya R.; van der Putten, P. Herman; Schmid, Peter

2013-01-01

Huntington's disease (HD) is an autosomal dominant, progressive and fatal neurological disorder caused by an expansion of CAG repeats in exon-1 of the huntingtin gene. The encoded poly-glutamine stretch renders mutant huntingtin prone to aggregation. HdhQ150 mice genocopy a pathogenic repeat (∼150 CAGs) in the endogenous mouse huntingtin gene and model predominantly pre-manifest HD. Treating early is likely important to prevent or delay HD, and HdhQ150 mice may be useful to assess therapeutic strategies targeting pre-manifest HD. This requires appropriate markers and here we demonstrate, that pre-symptomatic HdhQ150 mice show several dramatic mutant huntingtin gene-dose dependent pathological changes including: (i) an increase of neuronal intra-nuclear inclusions (NIIs) in brain, (ii) an increase of extra-nuclear aggregates in dentate gyrus, (iii) a decrease of DARPP32 protein and (iv) an increase in glial markers of neuroinflammation, which curiously did not correlate with local neuronal mutant huntingtin inclusion-burden. HdhQ150 mice developed NIIs also in all retinal neuron cell-types, demonstrating that retinal NIIs are not specific to human exon-1 R6 HD mouse models. Taken together, the striking and robust mutant huntingtin gene-dose related changes in aggregate-load, DARPP32 levels and glial activation markers should greatly facilitate future testing of therapeutic strategies in the HdhQ150 HD mouse model. PMID:24086450

Transgenic mice expressing mutant Pinin exhibit muscular dystrophy, nebulin deficiency and elevated expression of slow-type muscle fiber genes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Hsu-Pin; Hsu, Shu-Yuan; Wu, Wen-Ai

Highlights: •Pnn CCD domain functions as a dominant negative mutant regulating Pnn expression and function. •Pnn CCD mutant Tg mice have a muscle wasting phenotype during development and show dystrophic histological features. •Pnn mutant muscles are susceptible to slow fiber type gene transition and NEB reduction. •The Tg mouse generated by overexpression of the Pnn CCD domain displays many characteristics resembling NEB{sup +/−} mice. -- Abstract: Pinin (Pnn) is a nuclear speckle-associated SR-like protein. The N-terminal region of the Pnn protein sequence is highly conserved from mammals to insects, but the C-terminal RS domain-containing region is absent in lower species.more » The N-terminal coiled-coil domain (CCD) is, therefore, of interest not only from a functional point of view, but also from an evolutionarily standpoint. To explore the biological role of the Pnn CCD in a physiological context, we generated transgenic mice overexpressing Pnn mutant in skeletal muscle. We found that overexpression of the CCD reduces endogenous Pnn expression in cultured cell lines as well as in transgenic skeletal muscle fibers. Pnn mutant mice exhibited reduced body mass and impaired muscle function during development. Mutant skeletal muscles show dystrophic histological features with muscle fibers heavily loaded with centrally located myonuclei. Expression profiling and pathway analysis identified over-representation of genes in gene categories associated with muscle contraction, specifically those related to slow type fiber. In addition nebulin (NEB) expression level is repressed in Pnn mutant skeletal muscle. We conclude that Pnn downregulation in skeletal muscle causes a muscular dystrophic phenotype associated with NEB deficiency and the CCD domain is incapable of replacing full length Pnn in terms of functional capacity.« less

Deficient Gene Expression in Protein Kinase Inhibitor α Null Mutant Mice

PubMed Central

Gangolli, Esha A.; Belyamani, Mouna; Muchinsky, Sara; Narula, Anita; Burton, Kimberly A.; McKnight, G. Stanley; Uhler, Michael D.; Idzerda, Rejean L.

2000-01-01

Protein kinase inhibitor (PKI) is a potent endogenous inhibitor of the cyclic AMP (cAMP)-dependent protein kinase (PKA). It functions by binding the free catalytic (C) subunit with a high affinity and is also known to export nuclear C subunit to the cytoplasm. The significance of these actions with respect to PKI's physiological role is not well understood. To address this, we have generated by homologous recombination mutant mice that are deficient in PKIα, one of the three isoforms of PKI. The mice completely lack PKI activity in skeletal muscle and, surprisingly, show decreased basal and isoproterenol-induced gene expression in muscle. Further examination revealed reduced levels of the phosphorylated (active) form of the transcription factor CREB (cAMP response element binding protein) in the knockouts. This phenomenon stems, at least in part, from lower basal PKA activity levels in the mutants, arising from a compensatory increase in the level of the RIα subunit of PKA. The deficit in gene induction, however, is not easily explained by current models of PKI function and suggests that PKI may play an as yet undescribed role in PKA signaling. PMID:10779334

Cox4i2, Ifit2, and Prdm11 Mutant Mice: Effective Selection of Genes Predisposing to an Altered Airway Inflammatory Response from a Large Compendium of Mutant Mouse Lines.

PubMed

Horsch, Marion; Aguilar-Pimentel, Juan Antonio; Bönisch, Clemens; Côme, Christophe; Kolster-Fog, Cathrine; Jensen, Klaus T; Lund, Anders H; Lee, Icksoo; Grossman, Lawrence I; Sinkler, Christopher; Hüttemann, Maik; Bohn, Erwin; Fuchs, Helmut; Ollert, Markus; Gailus-Durner, Valérie; de Angelis, Martin Hrabĕ; Beckers, Johannes

2015-01-01

We established a selection strategy to identify new models for an altered airway inflammatory response from a large compendium of mutant mouse lines that were systemically phenotyped in the German Mouse Clinic (GMC). As selection criteria we included published gene functional data, as well as immunological and transcriptome data from GMC phenotyping screens under standard conditions. Applying these criteria we identified a few from several hundred mutant mouse lines and further characterized the Cox4i2tm1Hutt, Ifit2tm1.1Ebsb, and Prdm11tm1.1ahl lines following ovalbumin (OVA) sensitization and repeated OVA airway challenge. Challenged Prdm11tm1.1ahl mice exhibited changes in B cell counts, CD4+ T cell counts, and in the number of neutrophils in bronchoalveolar lavages, whereas challenged Ifit2tm1.1Ebsb mice displayed alterations in plasma IgE, IgG1, IgG3, and IgM levels compared to the challenged wild type littermates. In contrast, challenged Cox4i2tm1Hutt mutant mice did not show alterations in the humoral or cellular immune response compared to challenged wild type mice. Transcriptome analyses from lungs of the challenged mutant mouse lines showed extensive changes in gene expression in Prdm11tm1.1ahl mice. Functional annotations of regulated genes of all three mutant mouse lines were primarily related to inflammation and airway smooth muscle (ASM) remodeling. We were thus able to define an effective selection strategy to identify new candidate genes for the predisposition to an altered airway inflammatory response under OVA challenge conditions. Similar selection strategies may be used for the analysis of additional genotype-envirotype interactions for other diseases.

Cox4i2, Ifit2, and Prdm11 Mutant Mice: Effective Selection of Genes Predisposing to an Altered Airway Inflammatory Response from a Large Compendium of Mutant Mouse Lines

PubMed Central

Bönisch, Clemens; Côme, Christophe; Kolster-Fog, Cathrine; Jensen, Klaus T.; Lund, Anders H.; Lee, Icksoo; Grossman, Lawrence I.; Sinkler, Christopher; Hüttemann, Maik; Bohn, Erwin; Fuchs, Helmut; Ollert, Markus; Gailus-Durner, Valérie; Hrabĕ de Angelis, Martin; Beckers, Johannes

2015-01-01

We established a selection strategy to identify new models for an altered airway inflammatory response from a large compendium of mutant mouse lines that were systemically phenotyped in the German Mouse Clinic (GMC). As selection criteria we included published gene functional data, as well as immunological and transcriptome data from GMC phenotyping screens under standard conditions. Applying these criteria we identified a few from several hundred mutant mouse lines and further characterized the Cox4i2tm1Hutt, Ifit2tm1.1Ebsb, and Prdm11tm1.1ahl lines following ovalbumin (OVA) sensitization and repeated OVA airway challenge. Challenged Prdm11tm1.1ahl mice exhibited changes in B cell counts, CD4+ T cell counts, and in the number of neutrophils in bronchoalveolar lavages, whereas challenged Ifit2tm1.1Ebsb mice displayed alterations in plasma IgE, IgG1, IgG3, and IgM levels compared to the challenged wild type littermates. In contrast, challenged Cox4i2tm1Hutt mutant mice did not show alterations in the humoral or cellular immune response compared to challenged wild type mice. Transcriptome analyses from lungs of the challenged mutant mouse lines showed extensive changes in gene expression in Prdm11tm1.1ahl mice. Functional annotations of regulated genes of all three mutant mouse lines were primarily related to inflammation and airway smooth muscle (ASM) remodeling. We were thus able to define an effective selection strategy to identify new candidate genes for the predisposition to an altered airway inflammatory response under OVA challenge conditions. Similar selection strategies may be used for the analysis of additional genotype – envirotype interactions for other diseases. PMID:26263558

DISRUPTION OF THE PACAP GENE PROMOTES MEDULLOBLASTOMA IN PTC1 MUTANT MICE

PubMed Central

Lelievre, Vincent; Seksenyan, Akop; Nobuta, Hiroko; Yong, William H.; Chhith, Seririthanar; Niewiadomski, Pawel; Cohen, Joseph R.; Dong, Hongmei; Flores, Avegail; Liau, Linda M.; Kornblum, Harley I.; Scott, Matthew P.; Waschek, James A.

2008-01-01

Hedgehog (Hh) proteins and cAMP-dependent protein kinase A (PKA) generally play opposing roles in developmental patterning events. Humans and mice heterozygous for mutations in the Sonic hedgehog (Shh) receptor gene patched-1 (ptc1) have an increased incidence of certain types of cancer, including medulloblastoma (MB), a highly aggressive tumor of the cerebellum. Despite the importance of PKA in Hh signaling, little is known about how PKA activity is regulated in the context of Hh signaling, or the consequences of improper regulation. One molecule that can influence PKA activity is pituitary adenylyl cyclase activating peptide (PACAP), which has been shown to regulate cerebellar granule precursor proliferation in vitro, a cell population thought to give rise to MB. To test for a PACAP/Hh interaction in the initiation or propagation of these tumors, we introduced a PACAP mutation into ptc1 mutant mice. Deletion of a single copy of PACAP increased MB incidence approximate 2.5-fold, to 66%, thereby demonstrating that PACAP exerts a powerful inhibitory action on the induction, growth or survival of these tumors. Tumors from PACAP/ptc1 mutant mice retained PACAP receptor gene expression, and exhibited superinduction of Hh target genes compared to those from ptc1+/− mice. Moreover, PACAP inhibited proliferation of cell lines derived from tumors in a PKA-dependent manner, and inhibited expression of the Hh target gene gli1. The results provide genetic evidence that PACAP acts as a physiological factor that regulates the pathogenesis of Hh pathway-associated MB tumors. PMID:18036580

Interferon β induces clearance of mutant ataxin 7 and improves locomotion in SCA7 knock-in mice.

PubMed

Chort, Alice; Alves, Sandro; Marinello, Martina; Dufresnois, Béatrice; Dornbierer, Jean-Gabriel; Tesson, Christelle; Latouche, Morwena; Baker, Darren P; Barkats, Martine; El Hachimi, Khalid H; Ruberg, Merle; Janer, Alexandre; Stevanin, Giovanni; Brice, Alexis; Sittler, Annie

2013-06-01

We showed previously, in a cell model of spinocerebellar ataxia 7, that interferon beta induces the expression of PML protein and the formation of PML protein nuclear bodies that degrade mutant ataxin 7, suggesting that the cytokine, used to treat multiple sclerosis, might have therapeutic value in spinocerebellar ataxia 7. We now show that interferon beta also induces PML-dependent clearance of ataxin 7 in a preclinical model, SCA7(266Q/5Q) knock-in mice, and improves motor function. Interestingly, the presence of mutant ataxin 7 in the mice induces itself the expression of endogenous interferon beta and its receptor. Immunohistological studies in brains from two patients with spinocerebellar ataxia 7 confirmed that these modifications are also caused by the disease in humans. Interferon beta, administered intraperitoneally three times a week in the knock-in mice, was internalized with its receptor in Purkinje and other cells and translocated to the nucleus. The treatment induced PML protein expression and the formation of PML protein nuclear bodies and decreased mutant ataxin 7 in neuronal intranuclear inclusions, the hallmark of the disease. No reactive gliosis or other signs of toxicity were observed in the brain or internal organs. The performance of the SCA7(266Q/5Q) knock-in mice was significantly improved on two behavioural tests sensitive to cerebellar function: the Locotronic® Test of locomotor function and the Beam Walking Test of balance, motor coordination and fine movements, which are affected in patients with spinocerebellar ataxia 7. In addition to motor dysfunction, SCA7(266Q/5Q) mice present abnormalities in the retina as in patients: ataxin 7-positive neuronal intranuclear inclusions that were reduced by interferon beta treatment. Finally, since neuronal death does not occur in the cerebellum of SCA7(266Q/5Q) mice, we showed in primary cell cultures expressing mutant ataxin 7 that interferon beta treatment improves Purkinje cell survival.

Purkinje cells from RyR2 mutant mice are highly arrhythmogenic but responsive to targeted therapy.

PubMed

Kang, Guoxin; Giovannone, Steven F; Liu, Nian; Liu, Fang-Yu; Zhang, Jie; Priori, Silvia G; Fishman, Glenn I

2010-08-20

The Purkinje fiber network has been proposed as the source of arrhythmogenic Ca(2+) release events in catecholaminergic polymorphic ventricular tachycardia (CPVT), yet evidence supporting this mechanism at the cellular level is lacking. We sought to determine the frequency and severity of spontaneous Ca(2+) release events and the response to the antiarrhythmic agent flecainide in Purkinje cells and ventricular myocytes from RyR2(R4496C/+) CPVT mutant mice and littermate controls. We crossed RyR2(R4496C/+) knock-in mice with the newly described Cntn2-EGFP BAC transgenic mice, which express a fluorescent reporter gene in cells of the cardiac conduction system, including the distal Purkinje fiber network. Isolated ventricular myocytes (EGFP(-)) and Purkinje cells (EGFP(+)) from wild-type hearts and mutant hearts were distinguished by epifluorescence and intracellular Ca(2+) dynamics recorded by microfluorimetry. Both wild-type and RyR2(R4496C/+) mutant Purkinje cells displayed significantly slower kinetics of activation and relaxation compared to ventricular myocytes of the same genotype, and tau(decay) in the mutant Purkinje cells was significantly slower than that observed in wild-type Purkinje cells. Of the 4 groups studied, RyR2(R4496C/+) mutant Purkinje cells were also most likely to develop spontaneous Ca(2+) release events, and the number of events per cell was also significantly greater. Furthermore, with isoproterenol treatment, although all 4 groups showed increases in the frequency of arrhythmogenic Ca(2+(i)) events, the RyR2(R4496C/+) Purkinje cells responded with the most profound abnormalities in intracellular Ca(2+) handling, including a significant increase in the frequency of unstimulated Ca(2+(i)) events and the development of alternans, as well as isolated and sustained runs of triggered beats. Both Purkinje cells and ventricular myocytes from wild-type mice showed suppression of spontaneous Ca(2+) release events with flecainide, whereas in RyR2(R

Suppression of intestinal carcinogenesis in Apc-mutant mice by limonin.

PubMed

Shimizu, Satomi; Miyamoto, Shingo; Fujii, Gen; Nakanishi, Ruri; Onuma, Wakana; Ozaki, Yoshihiko; Fujimoto, Kyoko; Yano, Tomohiro; Mutoh, Michihiro

2015-07-01

Limonoids in citrus fruits are known to possess multiple biological functions, such as anti-proliferative functions in human cancer cell lines. Therefore, we aimed to investigate the suppressive effect of limonin on intestinal polyp development in Apc-mutant Min mice. Five-week-old female Min mice were fed a basal diet or a diet containing 250 or 500 ppm limonin for 8 weeks. The total number of polyps in mice treated with 500 ppm limonin decreased to 74% of the untreated control value. Neoplastic cell proliferation in the polyp parts was assessed by counting PCNA positive cells, and a tendency of reduction was obtained by limonin treatment. Moreover, expression levels of c-Myc and MCP-1 mRNA in the polyp part were reduced by administration of limonin. We finally confirmed the effects of limonin on β-catenin signaling, and found limonin significantly inhibited T-cell factor/lymphocyte enhancer factor-dependent transcriptional activity in a dose-dependent manner in the Caco-2 human colon cancer cell line. Our results suggest that limonin might be a candidate chemopreventive agent against intestinal carcinogenesis.

Altered striatal function in a mutant mouse lacking D1A dopamine receptors.

PubMed Central

Drago, J; Gerfen, C R; Lachowicz, J E; Steiner, H; Hollon, T R; Love, P E; Ooi, G T; Grinberg, A; Lee, E J; Huang, S P

1994-01-01

Of the five known dopamine receptors, D1A and D2 represent the major subtypes expressed in the striatum of the adult brain. Within the striatum, these two subtypes are differentially distributed in the two main neuronal populations that provide direct and indirect pathways between the striatum and the output nuclei of the basal ganglia. Movement disorders, including Parkinson disease and various dystonias, are thought to result from imbalanced activity in these pathways. Dopamine regulates movement through its differential effects on D1A receptors expressed by direct output neurons and D2 receptors expressed by indirect output neurons. To further examine the interaction of D1A and D2 neuronal pathways in the striatum, we used homologous recombination to generate mutant mice lacking functional D1A receptors (D1A-/-). D1A-/- mutants are growth retarded and die shortly after weaning age unless their diet is supplemented with hydrated food. With such treatment the mice gain weight and survive to adulthood. Neurologically, D1A-/- mice exhibit normal coordination and locomotion, although they display a significant decrease in rearing behavior. Examination of the striatum revealed changes associated with the altered phenotype of these mutants. D1A receptor binding was absent in striatal sections from D1A-/- mice. Striatal neurons normally expressing functional D1A receptors are formed and persist in adult homozygous mutants. Moreover, substance P mRNA, which is colocalized specifically in striatal neurons with D1A receptors, is expressed at a reduced level. In contrast, levels of enkephalin mRNA, which is expressed in striatal neurons with D2 receptors, are unaffected. These findings show that D1A-/- mice exhibit selective functional alterations in the striatal neurons giving rise to the direct striatal output pathway. Images Fig. 2 Fig. 4 PMID:7809078

Reduced heart size and increased myocardial fuel substrate oxidation in ACC2 mutant mice

PubMed Central

Essop, M. Faadiel; Camp, Heidi S.; Choi, Cheol Soo; Sharma, Saumya; Fryer, Ryan M.; Reinhart, Glenn A.; Guthrie, Patrick H.; Bentebibel, Assia; Gu, Zeiwei; Shulman, Gerald I.; Taegtmeyer, Heinrich; Wakil, Salih J.; Abu-Elheiga, Lutfi

2008-01-01

The cardiac-enriched isoform of acetyl-CoA carboxylase (ACC2) is a key regulator of mitochondrial fatty acid (FA) uptake via carnitine palmitoyltransferase 1 (CPT1). To test the hypothesis that oxidative metabolism is upregulated in hearts from animals lacking ACC2 (employing a transgenic Acc2-mutant mouse), we assessed cardiac function in vivo and determined rates of myocardial substrate oxidation ex vivo. When examined by echocardiography, there was no difference in systolic function, but left ventricular mass of the Acc2-mutant (MUT) mouse was significantly reduced (∼25%) compared with wild-types (WT). Reduced activation of the mammalian target of rapamycin (mTOR) and its downstream target p70S6K was found in MUT hearts. Exogenous oxidation rates of oleate were increased ∼22%, and, unexpectedly, exogenous glucose oxidation rates were also increased in MUT hearts. Using a hyperinsulinemic-euglycemic clamp, we found that glucose uptake in MUT hearts was increased by ∼83%. Myocardial triglyceride levels were significantly reduced in MUT vs. WT while glycogen content was the same. In parallel, transcript levels of PPARα and its target genes, pyruvate dehydrogenase kinase-4 (PDK-4), malonyl-CoA decarboxylase (MCD), and mCPT1, were downregulated in MUT mice. In summary, we report that 1) Acc2-mutant hearts exhibit a marked preference for the oxidation of both glucose and FAs coupled with greater utilization of endogenous fuel substrates (triglycerides), 2) attenuated mTOR signaling may result in reduced heart sizes observed in Acc2-mutant mice, and 3) Acc2-mutant hearts displayed normal functional parameters despite a significant decrease in size. PMID:18487439

A cerebellar learning model of vestibulo-ocular reflex adaptation in wild-type and mutant mice.

PubMed

Clopath, Claudia; Badura, Aleksandra; De Zeeuw, Chris I; Brunel, Nicolas

2014-05-21

Mechanisms of cerebellar motor learning are still poorly understood. The standard Marr-Albus-Ito theory posits that learning involves plasticity at the parallel fiber to Purkinje cell synapses under control of the climbing fiber input, which provides an error signal as in classical supervised learning paradigms. However, a growing body of evidence challenges this theory, in that additional sites of plasticity appear to contribute to motor adaptation. Here, we consider phase-reversal training of the vestibulo-ocular reflex (VOR), a simple form of motor learning for which a large body of experimental data is available in wild-type and mutant mice, in which the excitability of granule cells or inhibition of Purkinje cells was affected in a cell-specific fashion. We present novel electrophysiological recordings of Purkinje cell activity measured in naive wild-type mice subjected to this VOR adaptation task. We then introduce a minimal model that consists of learning at the parallel fibers to Purkinje cells with the help of the climbing fibers. Although the minimal model reproduces the behavior of the wild-type animals and is analytically tractable, it fails at reproducing the behavior of mutant mice and the electrophysiology data. Therefore, we build a detailed model involving plasticity at the parallel fibers to Purkinje cells' synapse guided by climbing fibers, feedforward inhibition of Purkinje cells, and plasticity at the mossy fiber to vestibular nuclei neuron synapse. The detailed model reproduces both the behavioral and electrophysiological data of both the wild-type and mutant mice and allows for experimentally testable predictions. Copyright © 2014 the authors 0270-6474/14/347203-13$15.00/0.

Shank3 mutant mice display autistic-like behaviours and striatal dysfunction

PubMed Central

Peça, João; Feliciano, Cátia; Ting, Jonathan T.; Wang, Wenting; Wells, Michael F.; Venkatraman, Talaignair N.; Lascola, Christopher D.; Fu, Zhanyan; Feng, Guoping

2011-01-01

Autism spectrum disorders (ASDs) comprise a range of disorders that share a core of neurobehavioural deficits characterized by widespread abnormalities in social interactions, deficits in communication as well as restricted interests and repetitive behaviours. The neurological basis and circuitry mechanisms underlying these abnormal behaviours are poorly understood. Shank3 is a postsynaptic protein, whose disruption at the genetic level is thought to be responsible for development of 22q13 deletion syndrome (Phelan-McDermid Syndrome) and other non-syndromic ASDs. Here we show that mice with Shank3 gene deletions exhibit self-injurious repetitive grooming and deficits in social interaction. Cellular, electrophysiological and biochemical analyses uncovered defects at striatal synapses and cortico-striatal circuits in Shank3 mutant mice. Our findings demonstrate a critical role for Shank3 in the normal development of neuronal connectivity and establish causality between a disruption in the Shank3 gene and the genesis of autistic like-behaviours in mice. PMID:21423165

Age-dependent synapse withdrawal at axotomised neuromuscular junctions in Wlds mutant and Ube4b/Nmnat transgenic mice

PubMed Central

Gillingwater, Thomas H; Thomson, Derek; Mack, Till G A; Soffin, Ellen M; Mattison, Richard J; Coleman, Michael P; Ribchester, Richard R

2002-01-01

Axons in WldS mutant mice are protected from Wallerian degeneration by overexpression of a chimeric Ube4b/Nmnat (Wld) gene. Expression of Wld protein was independent of age in these mice. However we identified two distinct neuromuscular synaptic responses to axotomy. In young adult Wlds mice, axotomy induced progressive, asynchronous synapse withdrawal from motor endplates, strongly resembling neonatal synapse elimination. Thus, five days after axotomy, 50–90 % of endplates were still partially or fully occupied and expressed endplate potentials (EPPs). By 10 days, fewer than 20 % of endplates still showed evidence of synaptic activity. Recordings from partially occupied junctions indicated a progressive decrease in quantal content in inverse proportion to endplate occupancy. In Wlds mice aged > 7 months, axons were still protected from axotomy but synapses degenerated rapidly, in wild-type fashion: within three days less than 5 % of endplates contained vestiges of nerve terminals. The axotomy-induced synaptic withdrawal phenotype decayed with a time constant of ∼30 days. Regenerated synapses in mature Wlds mice recapitulated the juvenile phenotype. Within 4–6 days of axotomy 30–50 % of regenerated nerve terminals still occupied motor endplates. Age-dependent synapse withdrawal was also seen in transgenic mice expressing the Wld gene. Co-expression of Wld protein and cyan fluorescent protein (CFP) in axons and neuromuscular synapses did not interfere with the protection from axotomy conferred by the Wld gene. Thus, Wld expression unmasks age-dependent, compartmentally organised programmes of synapse withdrawal and degeneration. PMID:12231635

Diet-induced obesity increases the frequency of Pig-a mutant erythrocytes in male C57BL/6J mice.

PubMed

Wickliffe, Jeffrey K; Dertinger, Stephen D; Torous, Dorothea K; Avlasevich, Svetlana L; Simon-Friedt, Bridget R; Wilson, Mark J

2016-12-01

Obesity increases the risk of a number of chronic diseases in humans including several cancers. Biological mechanisms responsible for such increased risks are not well understood at present. Increases in systemic inflammation and oxidative stress, endogenous production of mutagenic metabolites, altered signaling in proliferative pathways, and increased sensitivity to exogenous mutagens and carcinogens are some of the potential contributing factors. We hypothesize that obesity creates an endogenously mutagenic environment in addition to increasing the sensitivity to environmental mutagens. To test this hypothesis, we examined two in vivo genotoxicity endpoints. Pig-a mutant frequencies and micronucleus frequencies were determined in blood cells in two independent experiments in 30-week old male mice reared on either a high-fat diet (60% calories from fat) that exhibit an obese phenotype or a normal-fat diet (10% calories from fat) that do not exhibit an obese phenotype. Mice were assayed again at 52 weeks of age in one of the experiments. N-ethyl-N-nitrosourea (ENU) was used as a positive mutation control in one experiment. ENU induced a robust Pig-a mutant and micronucleus response in both phenotypes. Obese, otherwise untreated mice, did not differ from non-obese mice with respect to Pig-a mutant frequencies in reticulocytes or micronucleus frequencies. However, such mice, had significantly higher and sustained Pig-a mutant frequencies (increased 2.5-3.7-fold, p < 0.02) in erythrocytes as compared to non-obese mice (based on measurements collected at 30 weeks or 30 and 52 weeks of age). This suggests that obesity, in the absence of exposure to an exogenous mutagen, is itself mutagenic. Environ. Mol. Mutagen. 57:668-677, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

p53 deficiency alters the yield and spectrum of radiation-induced lacZ mutants in the brain of transgenic mice

NASA Technical Reports Server (NTRS)

Chang, P. Y.; Kanazawa, N.; Lutze-Mann, L.; Winegar, R. A.

2001-01-01

Exposure to heavy particle radiation in the galacto-cosmic environment poses a significant risk in space exploration and the evaluation of radiation-induced genetic damage in tissues, especially in the central nervous system, is an important consideration in long-term manned space missions. We used a plasmid-based transgenic mouse model system, with the pUR288 lacZ transgene integrated in the genome of every cell of C57Bl/6(lacZ) mice, to evaluate the genetic damage induced by iron particle radiation. In order to examine the importance of genetic background on the radiation sensitivity of individuals, we cross-bred p53 wild-type lacZ transgenic mice with p53 nullizygous mice, producing lacZ transgenic mice that were either hemizygous or nullizygous for the p53 tumor suppressor gene. Animals were exposed to an acute dose of 1 Gy of iron particles and the lacZ mutation frequency (MF) in the brain was measured at time intervals from 1 to 16 weeks post-irradiation. Our results suggest that iron particles induced an increase in lacZ MF (2.4-fold increase in p53+/+ mice, 1.3-fold increase in p53+/- mice and 2.1-fold increase in p53-/- mice) and that this induction is both temporally regulated and p53 genotype dependent. Characterization of mutants based on their restriction patterns showed that the majority of the mutants arising spontaneously are derived from point mutations or small deletions in all three genotypes. Radiation induced alterations in the spectrum of deletion mutants and reorganization of the genome, as evidenced by the selection of mutants containing mouse genomic DNA. These observations are unique in that mutations in brain tissue after particle radiation exposure have never before been reported owing to technical limitations in most other mutation assays.

Juvenile spermatogonial depletion (jsd): a genetic defect of germ cell proliferation of male mice.

PubMed

Beamer, W G; Cunliffe-Beamer, T L; Shultz, K L; Langley, S H; Roderick, T H

1988-05-01

Adult C57BL/6J male mice homozygous for the mutant gene, juvenile spermatogonial depletion (jsd/jsd), show azoosper4ia and testes reduced to one-third normal size, but are otherwise phenotypically normal. In contrast, adult jsd/jsd females are fully fertile. This feature facilitated mapping the jsd gene to the centromeric end of chromosome 1; the gene order is jsd-Isocitrate dehydrogenase-1 (Idh-1)-Peptidase-3 (Pep-3). Analysis of testicular histology from jsd/jsd mice aged 3-10 wk revealed that these mutant mice experience one wave of spermatogenesis, but fail to continue mitotic proliferation of type A spermatogonial cells at the basement membrane. As a consequence, histological sections of testes from mutant mice aged 8-52 wk showed tubules populated by modest numbers of Sertoli cells, with only an occasional spermatogonial cell. Some sperm with normal morphology and motility were observed in epididymides of 6.5- but not in 8-wk or older mutants. Treatment with retinol failed to alter the loss of spermatogenesis in jsd/jsd mice. Analyses of serum hormones of jsd/jsd males showed that testosterone levels were normal at all ages--a finding corroborated by normal seminal vesicle and vas deferens weights, whereas serum follicle-stimulating hormone levels were significantly elevated in mutant mice from 4 to 20 wk of age. We hypothesize the jsd/jsd male may be deficient in proliferative signals from Sertoli cells that are needed for spermatogenesis.

Mutant PFN1 causes ALS phenotypes and progressive motor neuron degeneration in mice by a gain of toxicity

PubMed Central

Yang, Chunxing; Danielson, Eric W.; Qiao, Tao; Metterville, Jake; Brown, Robert H.; Landers, John E.; Xu, Zuoshang

2016-01-01

Mutations in the profilin 1 (PFN1) gene cause amyotrophic lateral sclerosis (ALS), a neurodegenerative disease caused by the loss of motor neurons leading to paralysis and eventually death. PFN1 is a small actin-binding protein that promotes formin-based actin polymerization and regulates numerous cellular functions, but how the mutations in PFN1 cause ALS is unclear. To investigate this problem, we have generated transgenic mice expressing either the ALS-associated mutant (C71G) or wild-type protein. Here, we report that mice expressing the mutant, but not the wild-type, protein had relentless progression of motor neuron loss with concomitant progressive muscle weakness ending in paralysis and death. Furthermore, mutant, but not wild-type, PFN1 forms insoluble aggregates, disrupts cytoskeletal structure, and elevates ubiquitin and p62/SQSTM levels in motor neurons. Unexpectedly, the acceleration of motor neuron degeneration precedes the accumulation of mutant PFN1 aggregates. These results suggest that although mutant PFN1 aggregation may contribute to neurodegeneration, it does not trigger its onset. Importantly, these experiments establish a progressive disease model that can contribute toward identifying the mechanisms of ALS pathogenesis and the development of therapeutic treatments. PMID:27681617

Effect of nerve injury on the number of dorsal root ganglion neurons and autotomy behavior in adult Bax-deficient mice.

PubMed

Lyu, Chuang; Lyu, Gong-Wei; Martinez, Aurora; Shi, Tie-Jun Sten

2017-01-01

The proapoptotic molecule BAX, plays an important role in mitochondrial apoptotic pathway. Dorsal root ganglion (DRG) neurons depend on neurotrophic factors for survival at early developmental stages. Withdrawal of neurotrophic factors will induce apoptosis in DRG neurons, but this type of cell death can be delayed or prevented in neonatal Bax knockout (KO) mice. In adult animals, evidence also shows that DRG neurons are less dependent upon neurotrophic factors for survival. However, little is known about the effect of Bax deletion on the survival of normal and denervated DRG neurons in adult mice. A unilateral sciatic nerve transection was performed in adult Bax KO mice and wild-type (WT) littermates. Stereological method was employed to quantify the number of lumbar-5 DRG neurons 1 month post-surgery. Nerve injury-induced autotomy behavior was also examined on days 1, 3, and 7 post-surgery. There were significantly more neurons in contralateral DRGs of KO mice as compared with WT mice. The number of neurons was reduced in ipsilateral DRGs in both KO and WT mice. No changes in size distributions of DRG neuron profiles were detected before or after nerve injury. Injury-induced autotomy behavior developed much earlier and was more serious in KO mice. Although postnatal death or loss of DRG neurons is partially prevented by Bax deletion, this effect cannot interfere with long-term nerve injury-induced neuronal loss. The exaggerated self-amputation behavior observed in the mutant mice indicates that Bax deficiency may enhance the development of spontaneous pain following nerve injury.

Changes in the striatal proteome of YAC128Q mice exhibit gene-environment interactions between mutant huntingtin and manganese.

PubMed

Wegrzynowicz, Michal; Holt, Hunter K; Friedman, David B; Bowman, Aaron B

2012-02-03

Huntington's disease (HD) is a neurodegenerative disorder caused by expansion of a CAG repeat within the Huntingtin (HTT) gene, though the clinical presentation of disease and age-of-onset are strongly influenced by ill-defined environmental factors. We recently reported a gene-environment interaction wherein expression of mutant HTT is associated with neuroprotection against manganese (Mn) toxicity. Here, we are testing the hypothesis that this interaction may be manifested by altered protein expression patterns in striatum, a primary target of both neurodegeneration in HD and neurotoxicity of Mn. To this end, we compared striatal proteomes of wild-type and HD (YAC128Q) mice exposed to vehicle or Mn. Principal component analysis of proteomic data revealed that Mn exposure disrupted a segregation of WT versus mutant proteomes by the major principal component observed in vehicle-exposed mice. Identification of altered proteins revealed novel markers of Mn toxicity, particularly proteins involved in glycolysis, excitotoxicity, and cytoskeletal dynamics. In addition, YAC128Q-dependent changes suggest that axonal pathology may be an early feature in HD pathogenesis. Finally, for several proteins, genotype-specific responses to Mn were observed. These differences include increased sensitivity to exposure in YAC128Q mice (UBQLN1) and amelioration of some mutant HTT-induced alterations (SAE1, ENO1). We conclude that the interaction of Mn and mutant HTT may suppress proteomic phenotypes of YAC128Q mice, which could reveal potential targets in novel treatment strategies for HD.

Somatotroph hypoplasia and dwarfism in transgenic mice expressing a non-phosphorylatable CREB mutant.

PubMed

Struthers, R S; Vale, W W; Arias, C; Sawchenko, P E; Montminy, M R

1991-04-18

Most of the transcriptional effects of cyclic AMP are mediated by the cAMP response element binding protein (CREB). After activation of cAMP-dependent protein kinase A, the catalytic subunits of this enzyme apparently mediate the phosphorylation and activation of CREB. As cAMP serves as a mitogenic signal for anterior pituitary somatotrophic cells, we investigated whether CREB similarly regulates proliferation of these cells. We prepared transgenic mice expressing a transcriptionally inactive mutant of CREB (CREBM1), which cannot be phosphorylated, in cells of the anterior pituitary. If CREB activity is required for proliferation, the overexpressed mutant protein would effectively compete with wild-type CREB activity and thereby block the response to cAMP. As predicted, the CREBM1 transgenic mice exhibited a dwarf phenotype with atrophied pituitary glands markedly deficient in somatotroph but not other cell types. We conclude that transcriptional activation of CREB is necessary for the normal development of a highly restricted cell type, and that environmental cues, possibly provided by the hypothalamic growth hormone-releasing factor, are necessary for population of the pituitary by somatotrophic cells.

Relatively high rates of G:C → A:T transitions at CpG sites were observed in certain epithelial tissues including pancreas and submaxillary gland of adult big blue® mice.

PubMed

Prtenjaca, Anita; Tarnowski, Heather E; Marr, Alison M; Heney, Melanie A; Creamer, Laura; Sathiamoorthy, Sarmitha; Hill, Kathleen A

2014-01-01

With few exceptions, spontaneous mutation frequency and pattern are similar across tissue types and relatively constant in young to middle adulthood in wild type mice. Underrepresented in surveys of spontaneous mutations across murine tissues is the diversity of epithelial tissues. For the first time, spontaneous mutations were detected in pancreas and submaxillary gland and compared with kidney, lung, and male germ cells from five adult male Big Blue® mice. Mutation load was assessed quantitatively through measurement of mutant and mutation frequency and qualitatively through identification of mutations and characterization of recurrent mutations, multiple mutations, mutation pattern, and mutation spectrum. A total of 9.6 million plaque forming units were screened, 226 mutants were collected, and 196 independent mutations were identified. Four novel mutations were discovered. Spontaneous mutation frequency was low in pancreas and high in the submaxillary gland. The submaxillary gland had multiple recurrent mutations in each of the mice and one mutant had two independent mutations. Mutation patterns for epithelial tissues differed from that observed in male germ cells with a striking bias for G:C to A:T transitions at CpG sites. A comprehensive review of lacI spontaneous mutation patterns in young adult mice and rats identified additional examples of this mutational bias. An overarching observation about spontaneous mutation frequency in adult tissues of the mouse remains one of stability. A repeated observation in certain epithelial tissues is a higher rate of G:C to A:T transitions at CpG sites and the underlying mechanisms for this bias are not known. Copyright © 2013 Wiley Periodicals, Inc.

A Yersinia pestis lpxM-mutant live vaccine induces enhanced immunity against bubonic plague in mice and guinea pigs.

PubMed

Feodorova, V A; Pan'kina, L N; Savostina, E P; Sayapina, L V; Motin, V L; Dentovskaya, S V; Shaikhutdinova, R Z; Ivanov, S A; Lindner, B; Kondakova, A N; Bystrova, O V; Kocharova, N A; Senchenkova, S N; Holst, O; Pier, G B; Knirel, Y A; Anisimov, A P

2007-11-01

The lpxM mutant of the live vaccine Yersinia pestis EV NIIEG strain synthesising a less toxic penta-acylated lipopolysaccharide was found to be avirulent in mice and guinea pigs, notably showing no measurable virulence in Balb/c mice which do retain some susceptibility to the parental strain itself. Twenty-one days after a single injection of the lpxM-mutant, 85-100% protection was achieved in outbred mice and guinea pigs, whereas a 43% protection rate was achieved in Balb/c mice given single low doses (10(3) to 2.5 x 10(4) CFU) of this vaccine. A subcutaneous challenge with 2000 median lethal doses (equal to 20,000 CFU) of fully virulent Y. pestis 231 strain, is a 6-10-fold higher dose than that which the EV NIIEG itself can protect against.

Late-onset of spinal neurodegeneration in knock-in mice expressing a mutant BiP.

PubMed

Jin, Hisayo; Mimura, Naoya; Kashio, Makiko; Koseki, Haruhiko; Aoe, Tomohiko

2014-01-01

Most human neurodegenerative diseases are sporadic, and appear later in life. While the underlying mechanisms of the progression of those diseases are still unclear, investigations into the familial forms of comparable diseases suggest that endoplasmic reticulum (ER) stress is involved in the pathogenesis. Binding immunoglobulin protein (BiP) is an ER chaperone that is central to ER function. We produced knock-in mice expressing a mutant BiP that lacked the retrieval sequence in order to evaluate the effect of a functional defect in an ER chaperone in multi-cellular organisms. Here we report that heterozygous mutant BiP mice revealed motor disabilities in aging. We found a degeneration of some motoneurons in the spinal cord accompanied by accumulations of ubiquitinated proteins. The defect in retrieval of BiP by the KDEL receptor leads to impaired activities in quality control and autophagy, suggesting that functional defects in the ER chaperones may contribute to the late onset of neurodegenerative diseases.

Mutant prenyltransferase-like mitochondrial protein (PLMP) and mitochondrial abnormalities in kd/kd mice

PubMed Central

Peng, Min; Jarett, Leonard; Meade, Ray; Madaio, Michael P.; Hancock, Wayne W.; George, Alfred L.; Neilson, Eric G.; Gasser, David L.

2008-01-01

Background Mice that are homozygous for the kidney disease (kd) mutation are apparently healthy for the first 8 weeks of life, but spontaneously develop a severe form of interstitial nephritis that progresses to end-stage renal disease (ESRD) by 4 to 8 months of age. By testing for linkage to microsatellite markers, we previously localized the kd gene to a YAC/BAC contig. Methods The sequence of the entire critical region was examined, and candidate genes were identified. These candidate genes were sequenced in both mutant (kd/kd) mice and normal controls. The phenotype was further characterized by immunohistochemistry and electron microscopy. Transgenic mice were constructed that carried the wild-type allele of the prime candidate gene, and this transgene was transferred to a kd/kd background by breeding. Results We have obtained evidence that kd is a mutant allele of a novel gene for a prenyltransferase-like mitochondrial protein (PLMP). This gene is alternatively spliced, with the larger gene product having one domain that resembles transprenyltransferase and another that is similar to geranylgeranyl pyrophosphate synthase. The smaller gene product includes only the first domain. An antiserum to PLMP localizes to mitochondria, and ultrastructural defects are present in the mitochondria of renal tubular epithelial cells, and to a lesser extent, hepatocytes and heart cells from kd/kd mice. In a line of kd/kd mice that carried the wild-type PLMP allele as a transgene, only 1 out of 13 animals expressed the disease by 120 days of age. Conclusion The kd allele codes for a novel protein that localizes to the mitochondria, and the kd/kd mouse has dysmorphic mitochondria in the renal tubular epithelial cells. This mouse is therefore a unique animal model for studying mechanisms that lead to tubulointerstitial nephritis. PMID:15200409

Serial transmission in rodents of neurodegeneration from transgenic mice expressing mutant prion protein.

PubMed Central

Hsiao, K K; Groth, D; Scott, M; Yang, S L; Serban, H; Rapp, D; Foster, D; Torchia, M; Dearmond, S J; Prusiner, S B

1994-01-01

Two lines of transgenic (Tg) mice expressing high (H) levels of the mutant P101L prion protein (PrP) developed a neurologic illness and central nervous system pathology indistinguishable from experimental murine scrapie; these mice were designated Tg(MoPrP-P101L)H. Brain homogenates from Tg(MoPrP-P101L)H mice were inoculated intracerebrally into CD-1 Swiss mice, Syrian hamsters, and Tg196 mice, Tg mice expressing the MoPrP-P101L transgene at low levels. None of the CD-1 mice developed central nervous system dysfunction, whereas approximately 10% of hamsters and approximately 40% of the Tg196 mice manifested neurologic signs between 117 and 639 days after inoculation. Serial transmission of neurodegeneration in Tg196 mice and Syrian hamsters was initiated with brain extracts, producing incubation times of approximately 400 and approximately 75 days, respectively. Although the Tg(MoPrP-P101L)H mice appear to accumulate only low levels of infections prions in their brains, the serial transmission of disease to inoculated recipients argues that prion formation occurs de novo in the brains of these uninoculated animals. These Tg mouse studies, taken together with similar findings in humans dying of inherited prion diseases, provide additional evidence that prions lack a foreign nucleic acid. Images PMID:7916462

Medulloblastomas derived from Cxcr6 mutant mice respond to treatment with a smoothened inhibitor.

PubMed

Sasai, Ken; Romer, Justyna T; Kimura, Hiromichi; Eberhart, Derek E; Rice, Dennis S; Curran, Tom

2007-04-15

The sonic hedgehog (Shh) pathway is activated in approximately 30% of human medulloblastoma resulting in increased expression of downstream target genes. In about half of these cases, this has been shown to be a consequence of mutations in regulatory genes within the pathway, including Ptc1, Smo, and Sufu. However, for some tumors, no mutations have been detected in known pathway genes. This suggests that either mutations in other genes promote tumorigenesis or that epigenetic alterations increase pathway activity in these tumors. Here, we report that 3% to 4% of mice lacking either one or both functional copies of Cxcr6 develop medulloblastoma. Although CXCR6 is not known to be involved in Shh signaling, tumors derived from Cxcr6 mutant mice expressed Shh pathway target genes including Gli1, Gli2, Ptc2, and Sfrp1, indicating elevated pathway activity. Interestingly, the level of Ptc1 expression was decreased in tumor cells although two normal copies of Ptc1 were retained. This implies that reduced CXCR6 function leads to suppression of Ptc1 thereby increasing Smoothened function and promoting tumorigenesis. We used a direct transplant model to test the sensitivity of medulloblastoma arising in Cxcr6 mutant mice to a small-molecule inhibitor of Smoothened (HhAntag). We found that transplanted tumors were dramatically inhibited in mice treated for only 4 days with HhAntag. These findings suggest that HhAntag may be effective against tumors lacking mutations in known Shh pathway genes.

Pathogenesis of coxsackievirus A9 in mice: role of the viral arginine-glycine-aspartic acid motif.

PubMed

Harvala, Heli; Kalimo, Hannu; Stanway, Glyn; Hyypiä, Timo

2003-09-01

Coxsackievirus A9 (CAV9) contains an arginine-glycine-aspartic acid (RGD) motif which participates in cell entry. Mutants with alterations in the RGD-containing region were utilized to explore the importance of the tripeptide in the pathogenesis of CAV9 in mice. Using in situ hybridization, the parental CAV9 strain was observed to infect skeletal muscle (intercostal, platysma, lingual and thigh muscles) of newborn mice, whereas the RGD-less mutants were detectable only in platysma and lingual muscles. In addition, newborn mice infected with the mutants survived longer than CAV9-infected mice. In adult mice, the parental strain of CAV9, but not the mutants, achieved moderately high titres in the pancreas. These results suggest that the RGD motif has a significant role in the pathogenesis of CAV9 in mice but also that RGD-independent entry routes can be utilized in the infection of murine tissue.

Brucella abortus Cyclic β-1,2-Glucan Mutants Have Reduced Virulence in Mice and Are Defective in Intracellular Replication in HeLa Cells

PubMed Central

Briones, Gabriel; Iñón de Iannino, Nora; Roset, Mara; Vigliocco, Ana; Paulo, Patricia Silva; Ugalde, Rodolfo A.

2001-01-01

Null cyclic β-1,2-glucan synthetase mutants (cgs mutants) were obtained from Brucella abortus virulent strain 2308 and from B. abortus attenuated vaccinal strain S19. Both mutants show greater sensitivity to surfactants like deoxycholic acid, sodium dodecyl sulfate, and Zwittergent than the parental strains, suggesting cell surface alterations. Although not to the same extent, both mutants display reduced virulence in mice and defective intracellular multiplication in HeLa cells. The B. abortus S19 cgs mutant was completely cleared from the spleens of mice after 4 weeks, while the 2308 mutant showed a 1.5-log reduction of the number of brucellae isolated from the spleens after 12 weeks. These results suggest that cyclic β-1,2-glucan plays an important role in the residual virulence of the attenuated B. abortus S19 strain. Although the cgs mutant was cleared from the spleens earlier than the wild-type parental strain (B. abortus S19) and produced less inflammatory response, its ability to confer protection against the virulent strain B. abortus 2308 was fully retained. Equivalent levels of induction of spleen gamma interferon mRNA and anti-lipopolysaccharide (LPS) of immunoglobulin G2a (IgG2a) subtype antibodies were observed in mice injected with B. abortus S19 or the cgs mutant. However, the titer of anti-LPS antibodies of the IgG1 subtype induced by the cgs mutant was lower than that observed with the parental S19 strain, thus suggesting that the cgs mutant induces a relatively exclusive Th1 response. PMID:11401996

Drug discrimination and neurochemical studies in alpha7 null mutant mice: tests for the role of nicotinic alpha7 receptors in dopamine release.

PubMed

Quarta, Davide; Naylor, Christopher G; Barik, Jacques; Fernandes, Cathy; Wonnacott, Susan; Stolerman, Ian P

2009-04-01

The nicotine discriminative stimulus has been linked to beta2-containing (beta2*) nicotinic receptors, with little evidence of a role for alpha7 nicotinic receptors, because nicotine discrimination was very weak in beta2 null mutant mice but normal in alpha7 mutants. As both alpha7 and beta2* nicotinic receptors have been implicated in nicotine-stimulated dopamine overflow, this study focused on the dopamine-mediated element in the nicotine stimulus by examining cross-generalisation between amphetamine and nicotine. Male alpha7 nicotinic receptor null mutant mice and wild-type controls were bred in-house and trained to discriminate nicotine (0.8 mg/kg) or (+)-amphetamine (0.6 mg/kg) from saline in a two-lever procedure with a tandem VI-30 FR-10 schedule of food reinforcement. Dopamine release from striatal slices was determined in parallel experiments. An alpha7 nicotinic receptor-mediated component of dopamine release was demonstrated in tissue from wild-type mice using choline as a selective agonist. This response was absent in tissue from null mutant animals. The mutation did not influence acquisition of drug discriminations but subtly affected the results of cross-generalisation tests. In mice trained to discriminate nicotine or amphetamine, there was partial cross-generalisation in wild-type mice and, at certain doses, these effects were attenuated in mutants. Further support for an alpha7 nicotinic receptor-mediated component was provided by the ability of the alpha7 nicotinic receptor antagonist methyllycaconitine to attenuate responses to nicotine and amphetamine in wild-type mice. These findings support the concept of an alpha7 nicotinic receptor-mediated dopaminergic element in nicotine discrimination, warranting further tests with selective dopamine agonists.

Epidermal growth factor receptor plays a role in the regulation of liver and plasma lipid levels in adult male mice.

PubMed

Scheving, Lawrence A; Zhang, Xiuqi; Garcia, Oscar A; Wang, Rebecca F; Stevenson, Mary C; Threadgill, David W; Russell, William E

2014-03-01

Dsk5 mice have a gain of function in the epidermal growth factor receptor (EGFR), caused by a point mutation in the kinase domain. We analyzed the effect of this mutation on liver size, histology, and composition. We found that the livers of 12-wk-old male Dsk5 heterozygotes (+/Dsk5) were 62% heavier compared with those of wild-type controls (+/+). The livers of the +/Dsk5 mice compared with +/+ mice had larger hepatocytes with prominent, polyploid nuclei and showed modestly increased cell proliferation indices in both hepatocytes and nonparenchymal cells. An analysis of total protein, DNA, and RNA (expressed relative to liver weight) revealed no differences between the mutant and wild-type mice. However, the livers of the +/Dsk5 mice had more cholesterol but less phospholipid and fatty acid. Circulating cholesterol levels were twice as high in adult male +/Dsk5 mice but not in postweaned young male or female mice. The elevated total plasma cholesterol resulted mainly from an increase in low-density lipoprotein (LDL). The +/Dsk5 adult mouse liver expressed markedly reduced protein levels of LDL receptor, no change in proprotein convertase subtilisin/kexin type 9, and a markedly increased fatty acid synthase and 3-hydroxy-3-methyl-glutaryl-CoA reductase. Increased expression of transcription factors associated with enhanced cholesterol synthesis was also observed. Together, these findings suggest that the EGFR may play a regulatory role in hepatocyte proliferation and lipid metabolism in adult male mice, explaining why elevated levels of EGF or EGF-like peptides have been positively correlated to increased cholesterol levels in human studies.

Enhancement of DEN-induced liver tumorigenesis in heme oxygenase-1 G143H mutant transgenic mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Jianfeng; Wang, Dayong; Xiao, Haifeng

Heme oxygenase (HO) is the rate-limiting enzyme in heme metabolism. HO-1 exhibits anti-oxidative and anti-inflammatory function via the actions of its metabolite, respectively. A growing body of evidence demonstrates that HO-1 is implicated in the pathogenesis and progression of several types of cancer. However, whether HO-1 takes part in healthy-premalignant-malignant transformation is still undefined. In this study, we took advantage of transgenic mice which over-expressed HO-1 dominant negative mutant (HO-1 G143H) and observed its susceptibility to DEN-induced hepatocarcinogenesis. Our results indicate that HO-1 G143H mutant accelerates the progression of tumorigenesis and tumor growth. The mechanism is closely related to enhancementmore » of ROS production which induce more hepatocytes death and secretion of inflammatory cytokines, proliferation of surviving hepatocytes. Our result provides the direct evidence that HO-1 plays an important protective role in liver carcinogenesis. Alternatively, we suggest the possible explanation on effect of HO-1 promoter polymorphism which involved in tumorigenesis. - Highlights: • Enhancement of DEN-induced hepatocarcinogenesis in HO-1 G143H Tg mice. • HO-1G143H mutant enhanced DEN-induced ROS production and liver injury. • HO-1G143H mutant aggravated DEN-induced changes of inflammatory factors and cell proliferation.« less

Allele-Specific Silencing of Mutant mRNA Rescues Ultrastructural and Arrhythmic Phenotype in Mice Carriers of the R4496C Mutation in the Ryanodine Receptor Gene (RYR2).

PubMed

Bongianino, Rossana; Denegri, Marco; Mazzanti, Andrea; Lodola, Francesco; Vollero, Alessandra; Boncompagni, Simona; Fasciano, Silvia; Rizzo, Giulia; Mangione, Damiano; Barbaro, Serena; Di Fonso, Alessia; Napolitano, Carlo; Auricchio, Alberto; Protasi, Feliciano; Priori, Silvia G

2017-08-18

Mutations in the cardiac Ryanodine Receptor gene ( RYR2 ) cause dominant catecholaminergic polymorphic ventricular tachycardia (CPVT), a leading cause of sudden death in apparently healthy individuals exposed to emotions or physical exercise. We investigated the efficacy of allele-specific silencing by RNA interference to prevent CPVT phenotypic manifestations in our dominant CPVT mice model carriers of the heterozygous mutation R4496C in RYR2 . We developed an in vitro mRNA and protein-based assays to screen multiple siRNAs for their ability to selectively silence mutant RYR2 -R4496C mRNA over the corresponding wild-type allele. For the most performant of these siRNAs (siRYR2-U10), we evaluated the efficacy of an adeno-associated serotype 9 viral vector (AAV9) expressing miRYR2-U10 in correcting RyR2 (Ryanodine Receptor type 2 protein) function after in vivo delivery by intraperitoneal injection in neonatal and adult RyR2 R4496C/+ (mice heterozygous for the R4496C mutation in the RyR2) heterozygous CPVT mice. Transcriptional analysis showed that after treatment with miRYR2-U10, the ratio between wild-type and mutant RYR2 mRNA was doubled (from 1:1 to 2:1) confirming the ability of miRYR2-U10 to selectively inhibit RYR2 -R4496C mRNA, whereas protein quantification showed that total RyR2 was reduced by 15% in the heart of treated mice. Furthermore, AAV9-miRYR2-U10 effectively (1) reduced isoproterenol-induced delayed afterdepolarizations and triggered activity in infected cells, (2) reduced adrenergically mediated ventricular tachycardia in treated mice, (3) reverted ultrastructural abnormalities of junctional sarcoplasmic reticulum and transverse tubules, and (4) attenuated mitochondrial abnormalities. The study demonstrates that allele-specific silencing with miRYR2-U10 prevents life-threatening arrhythmias in CPVT mice, suggesting that the reduction of mutant RyR2 may be a novel therapeutic approach for CPVT. © 2017 American Heart Association, Inc.

Craniofacial skeletal defects of adult zebrafish glypican 4 (knypek) mutants

PubMed Central

LeClair, Elizabeth E.; Mui, Stephanie R.; Huang, Angela; Topczewska, Jolanta M.; Topczewski, Jacek

2010-01-01

The heparan sulfate proteoglycan Glypican 4 (Gpc4) is part of the Wnt/planar cell polarity pathway, which is required for convergence and extension during zebrafish gastrulation. To observe Glypican 4-deficient phenotypes at later stages, we rescued gpc4−/− (knypek) homozygotes and raised them for more than one year. Adult mutants showed diverse cranial malformations of both dermal and endochondral bones, ranging from shortening of the rostral-most skull to loss of the symplectic. Additionally, the adult palatoquadrate cartilage was disorganized, with abnormal chondrocyte orientation. To understand how the palatoquadrate cartilage normally develops, we examined a juvenile series of wild type and mutant specimens. This identified two novel domains of elongated chondrocytes in the larval palatoquadrate, which normally form prior to endochondral ossification. In contrast, gpc4−/− larvae never form these domains, suggesting a failure of chondrocyte orientation, though not differentiation. Our findings implicate Gpc4 in the regulation of zebrafish cartilage and bone morphogenesis. PMID:19777561

Global gene profiling of aging lungs in Atp8b1 mutant mice.

PubMed

Soundararajan, Ramani; Stearns, Timothy M; Czachor, Alexander; Fukumoto, Jutaro; Turn, Christina; Westermann-Clark, Emma; Breitzig, Mason; Tan, Lee; Lockey, Richard F; King, Benjamin L; Kolliputi, Narasaiah

2016-09-29

Recent studies implicate cardiolipin oxidation in several age-related diseases. Atp8b1 encoding Type 4 P-type ATPases is a cardiolipin transporter. Mutation in Atp8b1 gene or inflammation of the lungs impairs the capacity of Atp8b1 to clear cardiolipin from lung fluid. However, the link between Atp8b1 mutation and age-related gene alteration is unknown. Therefore, we investigated how Atp8b1 mutation alters age-related genes. We performed Affymetrix gene profiling of lungs isolated from young (7-9 wks, n=6) and aged (14 months, 14 M, n=6) C57BL/6 and Atp8b1 mutant mice. In addition, Ingenuity Pathway Analysis (IPA) was performed. Differentially expressed genes were validated by quantitative real-time PCR (qRT-PCR). Global transcriptome analysis revealed 532 differentially expressed genes in Atp8b1 lungs, 157 differentially expressed genes in C57BL/6 lungs, and 37 overlapping genes. IPA of age-related genes in Atp8b1 lungs showed enrichment of Xenobiotic metabolism and Nrf2-mediated signaling pathways. The increase in Adamts2 and Mmp13 transcripts in aged Atp8b1 lungs was validated by qRT-PCR. Similarly, the decrease in Col1a1 and increase in Cxcr6 transcripts was confirmed in both Atp8b1 mutant and C57BL/6 lungs. Based on transcriptome profiling, our study indicates that Atp8b1 mutant mice may be susceptible to age-related lung diseases.

Hypolipidemic effects of starch and γ-oryzanol from wx/ae double-mutant rice on BALB/c.KOR-Apoe(shl) mice.

PubMed

Nakaya, Makoto; Shojo, Aiko; Hirai, Hiroaki; Matsumoto, Kenji; Kitamura, Shinichi

2013-01-01

waxy/amylose-extender (wx/ae) double-mutant japonica rice (Oryza sativa L.) produces resistant starch (RS) and a large amount of γ-oryzanol. Our previous study has shown the hypolipidemic effect of wx/ae brown rice on mice. To identify the functional constituents of the hypolipidemic activity in wx/ae rice, we prepared pure wx/ae starch and γ-oryzanol from wx/ae rice and investigated their effect on the lipid metabolism in BALB/c.KOR/Stm Slc-Apoe(shl) mice. The mice were fed for 3 weeks a diet containing non-mutant rice starch, non-mutant rice starch plus γ-oryzanol, wx/ae starch, or wx/ae starch plus γ-oryzanol. γ-Oryzanol by itself had no effect on the lipid metabolism, and wx/ae starch prevented an accumulation of triacylglycerol (TAG) in the liver. Interestingly, the combination of wx/ae starch plus γ-oryzanol not only prevented a TAG accumulation in the liver, but also partially suppressed the rise in plasma TAG concentration, indicating that wx/ae starch and γ-oryzanol could have a synergistic effect on the lipid metabolism.

Morphology of the external genitalia of the adult male and female mice as an endpoint of sex differentiation

PubMed Central

Weiss, Dana A.; Rodriguez, Esequiel; Cunha, Tristan; Menshenina, Julia; Barcellos, Dale; Chan, Lok Yun; Risbridger, Gail; Baskin, Laurence; Cunha, Gerald

2013-01-01

Adult external genitalia (ExG) are the endpoints of normal sex differentiation. Detailed morphometric analysis and comparison of adult mouse ExG has revealed 10 homologous features distinguishing the penis and clitoris that define masculine vs. feminine sex differentiation. These features have enabled the construction of a simple metric to evaluate various intersex conditions in mutant or hormonally manipulated mice. This review focuses on the morphology of the adult mouse penis and clitoris through detailed analysis of histologic sections, scanning electron microscopy, and three-dimensional reconstruction. We also present previous results from evaluation of “non-traditional” mammals, such as the spotted hyena and wallaby to demonstrate the complex process of sex differentiation that involves not only androgen-dependent processes, but also estrogen-dependent and hormone-independent mechanisms. PMID:21893161

Ectopic norrin induces growth of ocular capillaries and restores normal retinal angiogenesis in Norrie disease mutant mice.

PubMed

Ohlmann, Andreas; Scholz, Michael; Goldwich, Andreas; Chauhan, Bharesh K; Hudl, Kristiane; Ohlmann, Anne V; Zrenner, Eberhart; Berger, Wolfgang; Cvekl, Ales; Seeliger, Mathias W; Tamm, Ernst R

2005-02-16

Norrie disease is an X-linked retinal dysplasia that presents with congenital blindness, sensorineural deafness, and mental retardation. Norrin, the protein product of the Norrie disease gene (NDP), is a secreted protein of unknown biochemical function. Norrie disease (Ndp(y/-)) mutant mice that are deficient in norrin develop blindness, show a distinct failure in retinal angiogenesis, and completely lack the deep capillary layers of the retina. We show here that the transgenic expression of ectopic norrin under control of a lens-specific promoter restores the formation of a normal retinal vascular network in Ndp(y/-) mutant mice. The improvement in structure correlates with restoration of neuronal function in the retina. In addition, lenses of transgenic mice with ectopic expression of norrin show significantly more capillaries in the hyaloid vasculature that surrounds the lens during development. In vitro, lenses of transgenic mice in coculture with microvascular endothelial cells induce proliferation of the cells. Transgenic mice with ectopic expression of norrin show more bromodeoxyuridine-labeled retinal progenitor cells at embryonic day 14.5 and thicker retinas at postnatal life than wild-type littermates, indicating a putative direct neurotrophic effect of norrin. These data provide direct evidence that norrin induces growth of ocular capillaries and that pharmacologic modulation of norrin might be used for treatment of the vascular abnormalities associated with Norrie disease or other vascular disorders of the retina.

Impaired discrimination learning in interneuronal NMDAR-GluN2B mutant mice.

PubMed

Brigman, Jonathan L; Daut, Rachel A; Saksida, Lisa; Bussey, Timothy J; Nakazawa, Kazu; Holmes, Andrew

2015-06-17

Previous studies have established a role for N-methyl-D-aspartate receptor (NMDAR) containing the GluN2B subunit in efficient learning behavior on a variety of tasks. Recent findings have suggested that NMDAR on GABAergic interneurons may underlie the modulation of striatal function necessary to balance efficient action with cortical excitatory input. Here we investigated how loss of GluN2B-containing NMDAR on GABAergic interneurons altered corticostriatal-mediated associative learning. Mutant mice (floxed-GluN2B×Ppp1r2-Cre) were generated to produce loss of GluN2B on forebrain interneurons and phenotyped on a touchscreen-based pairwise visual learning paradigm. We found that the mutants showed normal performance during Pavlovian and instrumental pretraining, but were significantly impaired on a discrimination learning task. Detailed analysis of the microstructure of discrimination performance revealed reduced win→stay behavior in the mutants. These results further support the role of NMDAR, and GluN2B in particular, on modulation of striatal function necessary for efficient choice behavior and suggest that NMDAR on interneurons may play a critical role in associative learning.

HoxB2 binds mutant SOD1 and is altered in transgenic model of ALS.

PubMed

Zhai, Jinbin; Lin, Hong; Canete-Soler, Rafaela; Schlaepfer, William W

2005-09-15

Mutations in Cu/Zn superoxide dismutase (SOD1) cause approximately 20% of familial amyotrophic lateral sclerosis by a toxic gain of function; however, the precise mechanisms remain unclear. Here, we report the identification of HoxB2, a homeodomain-containing transcription factor, as a G93A mutant SOD1 interactive protein in a yeast two-hybrid screen. We show that HoxB2 co-precipitates and co-localizes with mutant SOD1 in neuronal cell lines, as well as in brain and spinal cord of G93A mutant SOD1 transgenic mice. Mutagenesis further shows that this interaction is mediated by the central homeodomain of HoxB2. In motor neuron-like NSC-34 cells, overexpression of HoxB2 or its homeodomain decreases the insolubility of mutant SOD1 and inhibits G93A or G86R mutant SOD1-induced neuronal cell death. In human and mouse tissues, we show that expression of HoxB2 persists in adult spinal cord and is primarily localized in nuclei of motor neurons. In G93A transgenic mice, HoxB2 co-localizes with mutant SOD1 and is redistributed to perikarya and proximal neurites of motor neurons. In addition, there is progressive accumulation of HoxB2 and mutant SOD1 as punctate inclusions in the neuropil surrounding motor neurons. Taken together, our findings demonstrate that interaction of HoxB2 with mutant SOD1 occurs in motor neurons of G93A mutant SOD1 transgenic mice and suggest that this interaction may modulate the neurotoxicity of mutant SOD1.

Inactivation of JAK2/STAT3 Signaling Axis and Downregulation of M1 mAChR Cause Cognitive Impairment in klotho Mutant Mice, a Genetic Model of Aging

PubMed Central

Park, Seok-Joo; Shin, Eun-Joo; Min, Sun Seek; An, Jihua; Li, Zhengyi; Hee Chung, Yoon; Hoon Jeong, Ji; Bach, Jae-Hyung; Nah, Seung-Yeol; Kim, Won-Ki; Jang, Choon-Gon; Kim, Yong-Sun; Nabeshima, Yo-ichi; Nabeshima, Toshitaka; Kim, Hyoung-Chun

2013-01-01

We previously reported cognitive dysfunction in klotho mutant mice. In the present study, we further examined novel mechanisms involved in cognitive impairment in these mice. Significantly decreased janus kinase 2 (JAK2) and signal transducer and activator of transcription3 (STAT3) phosphorylation were observed in the hippocampus of klotho mutant mice. A selective decrease in protein expression and binding density of the M1 muscarinic cholinergic receptor (M1 mAChR) was observed in these mice. Cholinergic parameters (ie, acetylcholine (ACh), choline acetyltransferase (ChAT), and acetylcholinesterase (AChE)) and NMDAR-dependent long-term potentiation (LTP) were significantly impaired in klotho mutant mice. McN-A-343 (McN), an M1 mAChR agonist, significantly attenuated these impairments. AG490 (AG), a JAK2 inhibitor, counteracted the attenuating effects of McN, although AG did not significantly alter the McN-induced effect on AChE. Furthermore, AG significantly inhibited the attenuating effects of McN on decreased NMDAR-dependent LTP, protein kinase C βII, p-ERK, p-CREB, BDNF, and p-JAK2/p-STAT3-expression in klotho mutant mice. In addition, k252a, a BDNF receptor tyrosine kinase B (TrkB) inhibitor, significantly counteracted McN effects on decreased ChAT, ACh, and M1 mAChR and p-JAK2/p-STAT3 expression. McN-induced effects on cognitive impairment in klotho mutant mice were consistently counteracted by either AG or k252a. Our results suggest that inactivation of the JAK2/STAT3 signaling axis and M1 mAChR downregulation play a critical role in cognitive impairment observed in klotho mutant mice. PMID:23389690

Three Herpes Simplex Virus Type 1 Latency-Associated Transcript Mutants with Distinct and Asymmetric Effects on Virulence in Mice Compared with Rabbits

PubMed Central

Perng, Guey-Chuen; Esmaili, Daniel; Slanina, Susan M.; Yukht, Ada; Ghiasi, Homayon; Osorio, Nelson; Mott, Kevin R.; Maguen, Barak; Jin, Ling; Nesburn, Anthony B.; Wechsler, Steven L.

2001-01-01

Herpes simplex virus type 1 latency-associated transcript (LAT)-null mutants have decreased reactivation but normal virulence in rabbits and mice. We report here on dLAT1.5, a mutant with LAT nucleotides 76 to 1667 deleted. Following ocular infection of rabbits, dLAT1.5 reactivated at a lower rate than its wild-type parent McKrae (6.1 versus 11.8%; P = 0.0025 [chi-square test]). Reactivation was restored in the marker-rescued virus dLAT1.5R (12.6%; P = 0.53 versus wild type), confirming the importance of the deleted region in spontaneous reactivation. Compared with wild-type or marker-rescued virus, dLAT1.5 had similar or slightly reduced virulence in rabbits (based on survival following ocular infection). In contrast, in mice, dLAT1.5 had increased virulence (P < 0.0001). Thus, deletion of LAT nucleotides 76 to 1667 increased viral virulence in mice but not in rabbits. In contrast, we also report here that LAT2.9A, a LAT mutant that we previously reported to have increased virulence in rabbits (G. C. Perng, S. M. Slanina, A. Yuhkt, B. S. Drolet, W. J. Keleher, H. Ghiasi, A. B. Nesburn, and S. L. Wechsler, J. Virol. 73:920–929, 1999), had decreased virulence in mice (P = 0.03). In addition, we also found that dLAT371, a LAT mutant that we previously reported to have wild-type virulence in rabbits (G. C. Perng, S. M. Slanina, H. Ghiasi, A. B. Nesburn, and S. L. Wechsler, J. Virol. 70:2014–2018, 1996), had decreased virulence in mice (P < 0.05). Thus, these three mutants, each of which encodes a different LAT RNA, have different virulence phenotypes. dLAT1.5 had wild-type virulence in rabbits but increased virulence in mice. In contrast, LAT2.9A had increased virulence in rabbits but decreased virulence in mice, and dLAT371 had wild-type virulence in rabbits but decreased virulence in mice. Taken together, these results suggest that (i) the 5′ end of LAT and/or a gene that overlaps part of this region is involved in viral virulence, (ii) this virulence appears

Expression of Mutant Human DISC1 in Mice Supports Abnormalities in Differentiation of Oligodendrocytes

PubMed Central

Katsel, Pavel; Tan, Weilun; Abazyan, Bagrat; Davis, Kenneth L; Ross, Christopher; Pletnikov, Mikhail V; Haroutunian, Vahram

2011-01-01

Abnormalities in oligodendrocyte (OLG) differentiation and OLG gene expression deficit have been described in schizophrenia (SZ). Recent studies revealed a critical requirement for Disrupted-in-Schizophrenia 1 (DISC1) in neural development. Transgenic mice with forebrain restricted expression of mutant human DISC1 (ΔhDISC1) are characterized by neuroanatomical and behavioral abnormalities reminiscent of some features of SZ. We sought to determine whether the expression of ΔhDISC1 may influence the development of OLGs in this mouse model. OLG- and cell cycle-associated gene and protein expression were characterized in the forebrain of ΔhDISC1 mice during different stages of neurodevelopment (E15 and P1 days) and in adulthood. The results suggest that the expression of ΔhDISC1 exerts a significant influence on oligodendrocyte differentiation and function, evidenced by premature OLG differentiation and increased proliferation of their progenitors. Additional findings showed that neuregulin 1 and its receptors may be contributing factors to the observed upregulation of OLG genes. Thus, OLG function may be perturbed by mutant hDISC1 in a model system that provides new avenues for studying aspects of the pathogenesis of SZ. PMID:21605958

Dopamine-Dependent Compensation Maintains Motor Behavior in Mice with Developmental Ablation of Dopaminergic Neurons

PubMed Central

DeMaro, Joseph A.; Knoten, Amanda; Hoshi, Masato; Pehek, Elizabeth; Johnson, Eugene M.; Gereau, Robert W.

2013-01-01

The loss of dopaminergic neurons in the substantia nigra pars compacta (SNc) and consequent depletion of striatal dopamine are known to underlie the motor deficits observed in Parkinson's disease (PD). Adaptive changes in dopaminergic terminals and in postsynaptic striatal neurons can compensate for significant losses of striatal dopamine, resulting in preservation of motor behavior. In addition, compensatory changes independent of striatal dopamine have been proposed based on PD therapies that modulate nondopaminergic circuits within the basal ganglia. We used a genetic strategy to selectively destroy dopaminergic neurons in mice during development to determine the necessity of these neurons for the maintenance of normal motor behavior in adult and aged mice. We find that loss of 90% of SNc dopaminergic neurons and consequent depletion of >95% of striatal dopamine does not result in changes in motor behavior in young-adult or aged mice as evaluated by an extensive array of motor behavior tests. Treatment of aged mutant mice with the dopamine receptor antagonist haloperidol precipitated motor behavior deficits in aged mutant mice, indicating that <5% of striatal dopamine is sufficient to maintain motor function in these mice. We also found that mutant mice exhibit an exaggerated response to l-DOPA compared with control mice, suggesting that preservation of motor function involves sensitization of striatal dopamine receptors. Our results indicate that congenital loss of dopaminergic neurons induces remarkable adaptions in the nigrostriatal system where limited amounts of dopamine in the dorsal striatum can maintain normal motor function. PMID:24155314

Hyperactivity and Learning Deficits in Transgenic Mice Bearing a Human Mutant Thyroid Hormone β1 Receptor Gene

PubMed Central

McDonald, Michael P.; Wong, Rosemary; Goldstein, Gregory; Weintraub, Bruce; Cheng, Sheue-yann; Crawley, Jacqueline N.

1998-01-01

Resistance to thyroid hormone (RTH) is a human syndrome mapped to the thyroid receptor β (TRβ) gene on chromosome 3, representing a mutation of the ligandbinding domain of the TRβ gene. The syndrome is characterized by reduced tissue responsiveness to thyroid hormone and elevated serum levels of thyroid hormones. A common behavioral phenotype associated with RTH is attention deficit hyperactivity disorder (ADHD). To test the hypothesis that RTH produces attention deficits and/or hyperactivity, transgenic mice expressing a mutant TRβ gene were generated. The present experiment tested RTH transgenic mice from the PV kindred on behavioral tasks relevant to the primary features of ADHD: hyperactivity, sustained attention (vigilance), learning, and impulsivity. Male transgenic mice showed elevated locomotor activity in an open field compared to male wild-type littermate controls. Both male and female transgenic mice exhibited impaired learning of an autoshaping task, compared to wild-type controls. On a vigilance task in an operant chamber, there were no differences between transgenics and controls on the proportion of hits, response latency, or duration of stimulus tolerated. On an operant go/no-go task measuring sustained attention and impulsivity, there were no differences between controls and transgenics. These results indicate that transgenic mice bearing a mutant human TRβ gene demonstrate several behavioral characteristics of ADHD and may serve a valuable heuristic role in elucidating possible candidate genes in converging pathways for other causes of ADHD. PMID:10454355

Hyperactivity and learning deficits in transgenic mice bearing a human mutant thyroid hormone beta1 receptor gene.

PubMed

McDonald, M P; Wong, R; Goldstein, G; Weintraub, B; Cheng, S Y; Crawley, J N

1998-01-01

Resistance to thyroid hormone (RTH) is a human syndrome mapped to the thyroid receptor beta (TRbeta) gene on chromosome 3, representing a mutation of the ligand-binding domain of the TRbeta gene. The syndrome is characterized by reduced tissue responsiveness to thyroid hormone and elevated serum levels of thyroid hormones. A common behavioral phenotype associated with RTH is attention deficit hyperactivity disorder (ADHD). To test the hypothesis that RTH produces attention deficits and/or hyperactivity, transgenic mice expressing a mutant TRbeta gene were generated. The present experiment tested RTH transgenic mice from the PV kindred on behavioral tasks relevant to the primary features of ADHD: hyperactivity, sustained attention (vigilance), learning, and impulsivity. Male transgenic mice showed elevated locomotor activity in an open field compared to male wild-type littermate controls. Both male and female transgenic mice exhibited impaired learning of an autoshaping task, compared to wild-type controls. On a vigilance task in an operant chamber, there were no differences between transgenics and controls on the proportion of hits, response latency, or duration of stimulus tolerated. On an operant go/no-go task measuring sustained attention and impulsivity, there were no differences between controls and transgenics. These results indicate that transgenic mice bearing a mutant human TRbeta gene demonstrate several behavioral characteristics of ADHD and may serve a valuable heuristic role in elucidating possible candidate genes in converging pathways for other causes of ADHD.

Neurexin dysfunction in adult neurons results in autistic-like behavior in mice.

PubMed

Rabaneda, Luis G; Robles-Lanuza, Estefanía; Nieto-González, José Luis; Scholl, Francisco G

2014-07-24

Autism spectrum disorders (ASDs) comprise a group of clinical phenotypes characterized by repetitive behavior and social and communication deficits. Autism is generally viewed as a neurodevelopmental disorder where insults during embryonic or early postnatal periods result in aberrant wiring and function of neuronal circuits. Neurexins are synaptic proteins associated with autism. Here, we generated transgenic βNrx1ΔC mice in which neurexin function is selectively impaired during late postnatal stages. Whole-cell recordings in cortical neurons show an impairment of glutamatergic synaptic transmission in the βNrx1ΔC mice. Importantly, mutant mice exhibit autism-related symptoms, such as increased self-grooming, deficits in social interactions, and altered interaction for nonsocial olfactory cues. The autistic-like phenotype of βNrx1ΔC mice can be reversed after removing the mutant protein in aged animals. The defects resulting from disruption of neurexin function after the completion of embryonic and early postnatal development suggest that functional impairment of mature circuits can trigger autism-related phenotypes. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Peroxisome proliferator-activated receptor gamma agonist troglitazone induces colon tumors in normal C57BL/6J mice and enhances colonic carcinogenesis in Apc1638 N/+ Mlh1+/- double mutant mice.

PubMed

Yang, Kan; Fan, Kun-Hua; Lamprecht, Sergio A; Edelmann, Winfried; Kopelovich, Levy; Kucherlapati, Raju; Lipkin, Martin

2005-09-10

The role of the nuclear peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in colon tumorigenesis remains controversial. Notwithstanding evidence that PPAR-gamma ligands impede murine colorectal carcinogenesis, PPAR-gamma agonists have been shown to enhance in vivo tumor formation in mouse models of human colon cancer. Our study was designed to determine whether troglitazone (TGZ) induces colonic tumor formation in normal C57BL/6J mice and enhances colorectal carcinogenesis in double mutant Apc1638N/+ Mlh1+/- mice fed a standard AIN-76A diet. We report herein that not only does TGZ enhance carcinogenesis in the large intestine of mutant mice predisposed to intestinal carcinogenesis but TGZ also induces colonic tumors in normal mice without gene targeting or carcinogen administration. This observation indicates that preexisting mutational events are not necessary for induction of colonic tumors by activated PPAR-gamma in vivo. (c) 2005 Wiley-Liss, Inc.

Overexpression of survival motor neuron improves neuromuscular function and motor neuron survival in mutant SOD1 mice.

PubMed

Turner, Bradley J; Alfazema, Neza; Sheean, Rebecca K; Sleigh, James N; Davies, Kay E; Horne, Malcolm K; Talbot, Kevin

2014-04-01

Spinal muscular atrophy results from diminished levels of survival motor neuron (SMN) protein in spinal motor neurons. Low levels of SMN also occur in models of amyotrophic lateral sclerosis (ALS) caused by mutant superoxide dismutase 1 (SOD1) and genetic reduction of SMN levels exacerbates the phenotype of transgenic SOD1(G93A) mice. Here, we demonstrate that SMN protein is significantly reduced in the spinal cords of patients with sporadic ALS. To test the potential of SMN as a modifier of ALS, we overexpressed SMN in 2 different strains of SOD1(G93A) mice. Neuronal overexpression of SMN significantly preserved locomotor function, rescued motor neurons, and attenuated astrogliosis in spinal cords of SOD1(G93A) mice. Despite this, survival was not prolonged, most likely resulting from SMN mislocalization and depletion of gems in motor neurons of symptomatic mice. Our results reveal that SMN upregulation slows locomotor deficit onset and motor neuron loss in this mouse model of ALS. However, disruption of SMN nuclear complexes by high levels of mutant SOD1, even in the presence of SMN overexpression, might limit its survival promoting effects in this specific mouse model. Studies in emerging mouse models of ALS are therefore warranted to further explore the potential of SMN as a modifier of ALS. Copyright © 2014 Elsevier Inc. All rights reserved.

Bacteriophage-Resistant Mutants in Yersinia pestis: Identification of Phage Receptors and Attenuation for Mice

PubMed Central

Filippov, Andrey A.; Sergueev, Kirill V.; He, Yunxiu; Huang, Xiao-Zhe; Gnade, Bryan T.; Mueller, Allen J.; Fernandez-Prada, Carmen M.; Nikolich, Mikeljon P.

2011-01-01

Background Bacteriophages specific for Yersinia pestis are routinely used for plague diagnostics and could be an alternative to antibiotics in case of drug-resistant plague. A major concern of bacteriophage therapy is the emergence of phage-resistant mutants. The use of phage cocktails can overcome this problem but only if the phages exploit different receptors. Some phage-resistant mutants lose virulence and therefore should not complicate bacteriophage therapy. Methodology/Principal Findings The purpose of this work was to identify Y. pestis phage receptors using site-directed mutagenesis and trans-complementation and to determine potential attenuation of phage-resistant mutants for mice. Six receptors for eight phages were found in different parts of the lipopolysaccharide (LPS) inner and outer core. The receptor for R phage was localized beyond the LPS core. Most spontaneous and defined phage-resistant mutants of Y. pestis were attenuated, showing increase in LD50 and time to death. The loss of different LPS core biosynthesis enzymes resulted in the reduction of Y. pestis virulence and there was a correlation between the degree of core truncation and the impact on virulence. The yrbH and waaA mutants completely lost their virulence. Conclusions/Significance We identified Y. pestis receptors for eight bacteriophages. Nine phages together use at least seven different Y. pestis receptors that makes some of them promising for formulation of plague therapeutic cocktails. Most phage-resistant Y. pestis mutants become attenuated and thus should not pose a serious problem for bacteriophage therapy of plague. LPS is a critical virulence factor of Y. pestis. PMID:21980477

Bacteriophage-resistant mutants in Yersinia pestis: identification of phage receptors and attenuation for mice.

PubMed

Filippov, Andrey A; Sergueev, Kirill V; He, Yunxiu; Huang, Xiao-Zhe; Gnade, Bryan T; Mueller, Allen J; Fernandez-Prada, Carmen M; Nikolich, Mikeljon P

2011-01-01

Bacteriophages specific for Yersinia pestis are routinely used for plague diagnostics and could be an alternative to antibiotics in case of drug-resistant plague. A major concern of bacteriophage therapy is the emergence of phage-resistant mutants. The use of phage cocktails can overcome this problem but only if the phages exploit different receptors. Some phage-resistant mutants lose virulence and therefore should not complicate bacteriophage therapy. The purpose of this work was to identify Y. pestis phage receptors using site-directed mutagenesis and trans-complementation and to determine potential attenuation of phage-resistant mutants for mice. Six receptors for eight phages were found in different parts of the lipopolysaccharide (LPS) inner and outer core. The receptor for R phage was localized beyond the LPS core. Most spontaneous and defined phage-resistant mutants of Y. pestis were attenuated, showing increase in LD₅₀ and time to death. The loss of different LPS core biosynthesis enzymes resulted in the reduction of Y. pestis virulence and there was a correlation between the degree of core truncation and the impact on virulence. The yrbH and waaA mutants completely lost their virulence. We identified Y. pestis receptors for eight bacteriophages. Nine phages together use at least seven different Y. pestis receptors that makes some of them promising for formulation of plague therapeutic cocktails. Most phage-resistant Y. pestis mutants become attenuated and thus should not pose a serious problem for bacteriophage therapy of plague. LPS is a critical virulence factor of Y. pestis.

An Essential Physiological Role for MCT8 in Bone in Male Mice

PubMed Central

Leitch, Victoria D.; Di Cosmo, Caterina; Liao, Xiao-Hui; O’Boy, Sam; Galliford, Thomas M.; Evans, Holly; Croucher, Peter I.; Boyde, Alan; Dumitrescu, Alexandra; Weiss, Roy E.; Refetoff, Samuel; Williams, Graham R.

2017-01-01

T3 is an important regulator of skeletal development and adult bone maintenance. Thyroid hormone action requires efficient transport of T4 and T3 into target cells. We hypothesized that monocarboxylate transporter (MCT) 8, encoded by Mct8 on the X-chromosome, is an essential thyroid hormone transporter in bone. To test this hypothesis, we determined the juvenile and adult skeletal phenotypes of male Mct8 knockout mice (Mct8KO) and Mct8D1D2KO compound mutants, which additionally lack the ability to convert the prohormone T4 to the active hormone T3. Prenatal skeletal development was normal in both Mct8KO and Mct8D1D2KO mice, whereas postnatal endochondral ossification and linear growth were delayed in both Mct8KO and Mct8D1D2KO mice. Furthermore, bone mass and mineralization were decreased in adult Mct8KO and Mct8D1D2KO mice, and compound mutants also had reduced bone strength. Delayed bone development and maturation in Mct8KO and Mct8D1D2KO mice is consistent with decreased thyroid hormone action in growth plate chondrocytes despite elevated serum T3 concentrations, whereas low bone mass and osteoporosis reflects increased thyroid hormone action in adult bone due to elevated systemic T3 levels. These studies identify an essential physiological requirement for MCT8 in chondrocytes, and demonstrate a role for additional transporters in other skeletal cells during adult bone maintenance. PMID:28637283

A Yersinia pestis YscN ATPase mutant functions as a live attenuated vaccine against bubonic plague in mice.

PubMed

Bozue, Joel; Cote, Christopher K; Webster, Wendy; Bassett, Anthony; Tobery, Steven; Little, Stephen; Swietnicki, Wieslaw

2012-07-01

Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. The bacterium uses the pLcr plasmid-encoded type III secretion system to deliver virulence factors into host cells. Delivery requires ATP hydrolysis by the YscN ATPase encoded by the yscN gene also on pLcr. A yscN mutant was constructed in the fully virulent CO92 strain containing a nonpolar, in-frame internal deletion within the gene. We demonstrate that CO92 with a yscN mutation was not able to secrete the LcrV protein (V-Antigen) and attenuated in a subcutaneous model of plague demonstrating that the YscN ATPase was essential for virulence. However, if the yscN mutant was complemented with a functional yscN gene in trans, virulence was restored. To evaluate the mutant as a live vaccine, Swiss-Webster mice were vaccinated twice with the ΔyscN mutant at varying doses and were protected against bubonic plague in a dose-dependent manner. Antibodies to F1 capsule but not to LcrV were detected in sera from the vaccinated mice. These preliminary results suggest a proof-of-concept for an attenuated, genetically engineered, live vaccine effective against bubonic plague. Published 2012. This article is a US Government work and is in the public domain in the USA.

DNase I hypersensitivity and epsilon-globin transcriptional enhancement are separable in locus control region (LCR) HS1 mutant human beta-globin YAC transgenic mice.

PubMed

Shimotsuma, Motoshi; Okamura, Eiichi; Matsuzaki, Hitomi; Fukamizu, Akiyoshi; Tanimoto, Keiji

2010-05-07

Expression of the five beta-like globin genes (epsilon, Ggamma, Agamma, delta, beta) in the human beta-globin locus depends on enhancement by the locus control region, which consists of five DNase I hypersensitive sites (5'HS1 through 5'HS5). We report here a novel enhancer activity in 5'HS1 that appears to be potent in transfected K562 cells. Deletion analyses identified a core activating element that bound to GATA-1, and a two-nucleotide mutation that disrupted GATA-1 binding in vitro abrogated 5'HS1 enhancer activity in transfection experiments. To determine the in vivo role of this GATA site, we generated multiple lines of human beta-globin YAC transgenic mice bearing the same two-nucleotide mutation. In the mutant mice, epsilon-, but not gamma-globin, gene expression in primitive erythroid cells was severely attenuated, while adult beta-globin gene expression in definitive erythroid cells was unaffected. Interestingly, DNaseI hypersensitivity near the 5'HS1 mutant sequence was eliminated in definitive erythroid cells, whereas it was only mildly affected in primitive erythroid cells. We therefore conclude that, although the GATA site in 5'HS1 is critical for efficient epsilon-globin gene expression, hypersensitive site formation per se is independent of 5'HS1 function, if any, in definitive erythroid cells.

Enriching the Environment of [alpha]CaMKII[superscript T286A] Mutant Mice Reveals that LTD Occurs in Memory Processing but Must be Subsequently Reversed by LTP

ERIC Educational Resources Information Center

Soto, Florentina; Giese, K. Peter; Edwards, Frances A.; Parsley, Stephanie L.; Pilgram, Sara M.

2007-01-01

[alpha]CaMKII[superscript T286A] mutant mice lack long-term potentiation (LTP) in the hippocampal CA1 region and are impaired in spatial learning. In situ hybridization confirms that the mutant mice show the same developmental expression of [alpha]CaMKII as their wild-type littermates. A simple hypothesis would suggest that if LTP is a substrate…

An Antibody to Notch2 Reverses the Osteopenic Phenotype of Hajdu-Cheney Mutant Male Mice

PubMed Central

Sanjay, Archana; Yu, Jungeun; Zanotti, Stefano

2017-01-01

Notch receptors play a central role in skeletal development and bone remodeling. Hajdu-Cheney syndrome (HCS), a disease characterized by osteoporosis and fractures, is associated with gain-of-NOTCH2 function mutations. To study HCS, we created a mouse model harboring a point 6955C>T mutation in the Notch2 locus upstream of the proline, glutamic acid, serine, and threonine domain, leading to a Q2319X change at the amino acid level. Notch2Q2319X heterozygous mutants exhibited cancellous and cortical bone osteopenia. Microcomputed tomography demonstrated that the cancellous and cortical osteopenic phenotype was reversed by the administration of antibodies generated against the negative regulatory region (NRR) of Notch2, previously shown to neutralize Notch2 activity. Bone histomorphometry revealed that anti-Notch2 NRR antibodies decreased the osteoclast number and eroded surface in cancellous bone of Notch2Q2319X mice. An increase in osteoclasts on the endocortical surface of Notch2Q2319X mice was not observed in the presence of anti-Notch2 NRR antibodies. The anti-Notch2 NRR antibody decreased the induction of Notch target genes and Tnfsf11 messenger RNA levels in bone extracts and osteoblasts from Notch2Q2319X mice. In vitro experiments demonstrated increased osteoclastogenesis in Notch2Q2319X mutants in response to macrophage colony-stimulating factor and receptor activator of nuclear factor–κB ligand, and these effects were suppressed by the anti-Notch2 NRR. In conclusion, Notch2Q2319X mice exhibit cancellous and cortical bone osteopenia that can be corrected by the administration of anti-Notch2 NRR antibodies. PMID:28323963

Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice.

PubMed

Zhang, Honghao; Kamiya, Nobuhiro; Tsuji, Takehito; Takeda, Haruko; Scott, Greg; Rajderkar, Sudha; Ray, Manas K; Mochida, Yoshiyuki; Allen, Benjamin; Lefebvre, Veronique; Hung, Irene H; Ornitz, David M; Kunieda, Tetsuo; Mishina, Yuji

2016-12-01

Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome.

Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice

PubMed Central

Zhang, Honghao; Kamiya, Nobuhiro; Tsuji, Takehito; Takeda, Haruko; Scott, Greg; Ray, Manas K.; Mochida, Yoshiyuki; Lefebvre, Veronique; Hung, Irene H.; Kunieda, Tetsuo; Mishina, Yuji

2016-01-01

Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome. PMID:28027321

Spontaneous hepatic repopulation in transgenic mice expressing mutant human α1-antitrypsin by wild-type donor hepatocytes

PubMed Central

Ding, Jianqiang; Yannam, Govardhana R.; Roy-Chowdhury, Namita; Hidvegi, Tunda; Basma, Hesham; Rennard, Stephen I.; Wong, Ronald J.; Avsar, Yesim; Guha, Chandan; Perlmutter, David H.; Fox, Ira J.; Roy-Chowdhury, Jayanta

2011-01-01

α1-Antitrypsin deficiency is an inherited condition that causes liver disease and emphysema. The normal function of this protein, which is synthesized by the liver, is to inhibit neutrophil elastase, a protease that degrades connective tissue of the lung. In the classical form of the disease, inefficient secretion of a mutant α1-antitrypsin protein (AAT-Z) results in its accumulation within hepatocytes and reduced protease inhibitor activity, resulting in liver injury and pulmonary emphysema. Because mutant protein accumulation increases hepatocyte cell stress, we investigated whether transplanted hepatocytes expressing wild-type AAT might have a competitive advantage relative to AAT-Z–expressing hepatocytes, using transgenic mice expressing human AAT-Z. Wild-type donor hepatocytes replaced 20%–98% of mutant host hepatocytes, and repopulation was accelerated by injection of an adenovector expressing hepatocyte growth factor. Spontaneous hepatic repopulation with engrafted hepatocytes occurred in the AAT-Z–expressing mice even in the absence of severe liver injury. Donor cells replaced both globule-containing and globule-devoid cells, indicating that both types of host hepatocytes display impaired proliferation relative to wild-type hepatocytes. These results suggest that wild-type hepatocyte transplantation may be therapeutic for AAT-Z liver disease and may provide an alternative to protein replacement for treating emphysema in AAT-ZZ individuals. PMID:21505264

Spontaneous hepatic repopulation in transgenic mice expressing mutant human α1-antitrypsin by wild-type donor hepatocytes.

PubMed

Ding, Jianqiang; Yannam, Govardhana R; Roy-Chowdhury, Namita; Hidvegi, Tunda; Basma, Hesham; Rennard, Stephen I; Wong, Ronald J; Avsar, Yesim; Guha, Chandan; Perlmutter, David H; Fox, Ira J; Roy-Chowdhury, Jayanta

2011-05-01

α1-Antitrypsin deficiency is an inherited condition that causes liver disease and emphysema. The normal function of this protein, which is synthesized by the liver, is to inhibit neutrophil elastase, a protease that degrades connective tissue of the lung. In the classical form of the disease, inefficient secretion of a mutant α1-antitrypsin protein (AAT-Z) results in its accumulation within hepatocytes and reduced protease inhibitor activity, resulting in liver injury and pulmonary emphysema. Because mutant protein accumulation increases hepatocyte cell stress, we investigated whether transplanted hepatocytes expressing wild-type AAT might have a competitive advantage relative to AAT-Z-expressing hepatocytes, using transgenic mice expressing human AAT-Z. Wild-type donor hepatocytes replaced 20%-98% of mutant host hepatocytes, and repopulation was accelerated by injection of an adenovector expressing hepatocyte growth factor. Spontaneous hepatic repopulation with engrafted hepatocytes occurred in the AAT-Z-expressing mice even in the absence of severe liver injury. Donor cells replaced both globule-containing and globule-devoid cells, indicating that both types of host hepatocytes display impaired proliferation relative to wild-type hepatocytes. These results suggest that wild-type hepatocyte transplantation may be therapeutic for AAT-Z liver disease and may provide an alternative to protein replacement for treating emphysema in AAT-ZZ individuals.

The effect of nitric oxide synthase inhibitors nitro-L-arginine and 7-nitroindazole on spatial learning and motor functions in Lurcher mutant and wild type mice.

PubMed

Markvartová, V; Vozeh, F

2008-01-01

Nitric oxide (NO) is an intercellular messenger that, among other things, plays an important role in the nervous system as a gaseous neurotransmitter, modulating long-term potentiation (LTP) induction of synaptic transmission. LTP has been suggested to be the basis of memory formation. On the other hand NO also participates in excitotoxic processes which play an important role in many neuropathological states. The aim of this work was to observe the effect of two NO synthase (NOS) inhibitors (N omega-Nitro-L-arginine, NA; 7-nitroindazole, NI) on spontaneous behaviour, spatial learning and motor functions in Lurcher (+/Lc) and wild type (+/+) mice, derived from the B6CBA strain. Heterozygous Lurcher mutant mice represent a natural model of the olivocerebellar degeneration. They suffer from postnatal, practically total, extinction of cerebellar Purkinje cells (due to the excitotoxic apoptosis) and a partial decrease of granule cells and inferior olive neurons (ION) because of the lost target of their axons. +/+ animals are healthy littermates of +/Lc. NA is a nonselective NOS inhibitor which influences, except neuronal (n), also endothelial (e) NOS with an impact on blood pressure, NI is a selective nNOS inhibitor without any circulatory effect. The adult animals of both types (+/Lc; +/+) were influenced by acute administration of both inhibitors (25 mg/kg i.p. 30 min. before experiments) and newborns only by both acute and long-term administration of NI (1 month, starting from postnatal day 2, P2). Control solutions - saline or solvents of both NA and NI inhibitors--diluted 1M HCl and dimethyl sulfoxide (DMSO) respectively, were given at a relevant volume in the same way. The effect of both inhibitors and control solutions on motor functions was tested using four standard procedures (horizontal wire, slanting ladder, rotating cylinder, foot-bridge); in newborns at the age of 14 days. Spatial learning ability was examined in five-day long procedure in the Morris

Metabolic roles of the M3 muscarinic acetylcholine receptor studied with M3 receptor mutant mice: a review.

PubMed

Gautam, Dinesh; Jeon, Jongrye; Li, Jian Hua; Han, Sung-Jun; Hamdan, Fadi F; Cui, Yinghong; Lu, Huiyan; Deng, Chuxia; Gavrilova, Oksana; Wess, Jürgen

2008-01-01

The M(3) muscarinic acetylcholine (ACh) receptor (M(3) mAChR) is expressed in many central and peripheral tissues. It is a prototypic member of the superfamily of G protein-coupled receptors and preferentially activates G proteins of the G(q) family. Recent studies involving the use of newly generated mAChR mutant mice have revealed that the M(3) mAChR plays a key role in regulating many important metabolic functions. Phenotypic analyses of mutant mice that either selectively lacked or overexpressed M(3) receptors in pancreatic beta -cells indicated that beta -cell M(3) mAChRs are essential for maintaining proper insulin release and glucose homeostasis. The experimental data also suggested that strategies aimed at enhancing signaling through beta -cell M(3) mAChRs might be beneficial for the treatment of type 2 diabetes. Recent studies with whole body M(3) mAChR knockout mice showed that the absence of M(3) receptors protected mice against various forms of experimentally or genetically induced obesity and obesity-associated metabolic deficits. Under all experimental conditions tested, M(3) receptor-deficient mice showed greatly ameliorated impairments in glucose homeostasis and insulin sensitivity, reduced food intake, and a significant elevation in basal and total energy expenditure, most likely due to increased central sympathetic outflow and increased rate of fatty acid oxidation. These findings are of potential interest for the development of novel therapeutic approaches for the treatment of obesity and associated metabolic disorders.

Expression and function of orphan nuclear receptor TLX in adult neural stem cells.

PubMed

Shi, Yanhong; Chichung Lie, D; Taupin, Philippe; Nakashima, Kinichi; Ray, Jasodhara; Yu, Ruth T; Gage, Fred H; Evans, Ronald M

2004-01-01

The finding of neurogenesis in the adult brain led to the discovery of adult neural stem cells. TLX was initially identified as an orphan nuclear receptor expressed in vertebrate forebrains and is highly expressed in the adult brain. The brains of TLX-null mice have been reported to have no obvious defects during embryogenesis; however, mature mice suffer from retinopathies, severe limbic defects, aggressiveness, reduced copulation and progressively violent behaviour. Here we show that TLX maintains adult neural stem cells in an undifferentiated, proliferative state. We show that TLX-expressing cells isolated by fluorescence-activated cell sorting (FACS) from adult brains can proliferate, self-renew and differentiate into all neural cell types in vitro. By contrast, TLX-null cells isolated from adult mutant brains fail to proliferate. Reintroducing TLX into FACS-sorted TLX-null cells rescues their ability to proliferate and to self-renew. In vivo, TLX mutant mice show a loss of cell proliferation and reduced labelling of nestin in neurogenic areas in the adult brain. TLX can silence glia-specific expression of the astrocyte marker GFAP in neural stem cells, suggesting that transcriptional repression may be crucial in maintaining the undifferentiated state of these cells.

Spontaneous Pneumocystis carinii pneumonia in immunodeficient mutant scid mice. Natural history and pathobiology.

PubMed Central

Roths, J. B.; Marshall, J. D.; Allen, R. D.; Carlson, G. A.; Sidman, C. L.

1990-01-01

The opportunistic pathogen Pneumocystis carinii (Pc) poses a major clinical health problem in individuals with immune deficiency, including those patients with human immunodeficiency (HIV)-associated acquired immune deficiency disease (AIDS). Heretofore, in vivo investigations of the biology of Pc and pathogenesis of pneumocystosis have generally employed steroid-induced immune suppression with antibiotic prophylaxis and protein deprivation. This approach has many drawbacks, chief among them being the widespread, multiple interacting effects caused by the inducing agents. Athymic (nude) mice and rats have been used, but are less than ideal, as the immune defect primarily affects T lymphocytes. This article describes the natural history, pathobiology, and environmental effects on Pc pneumonitis in nonaxenically housed mice homozygous for the autosomal recessive mutation 'severe combined immunodeficiency' (scid), which almost totally lack both cell-mediated and antibody-mediated immune functions. The predictability, unequivocal expression, high morbidity, and well-defined genetic basis make scid/scid mutant mice the model of choice for in vivo studies of spontaneous pneumocystosis. Images Figure 3 Figure 6 PMID:2349968

Early-onset lymphoma and extensive embryonic apoptosis in two domain-specific Fen1 mice mutants.

PubMed

Larsen, Elisabeth; Kleppa, Liv; Meza, Trine J; Meza-Zepeda, Leonardo A; Rada, Christina; Castellanos, Cesilie G; Lien, Guro F; Nesse, Gaute J; Neuberger, Michael S; Laerdahl, Jon K; William Doughty, Richard; Klungland, Arne

2008-06-15

Flap endonuclease 1 (FEN1) processes Okazaki fragments in lagging strand DNA synthesis, and FEN1 is involved in several DNA repair pathways. The interaction of FEN1 with the proliferating cell nuclear antigen (PCNA) processivity factor is central to the function of FEN1 in both DNA replication and repair. Here we present two gene-targeted mice with mutations in FEN1. The first mutant mouse carries a single amino acid point mutation in the active site of the nuclease domain of FEN1 (Fen1(E160D/E160D)), and the second mutant mouse contains two amino acid substitutions in the highly conserved PCNA interaction domain of FEN1 (Fen1(DeltaPCNA/DeltaPCNA)). Fen1(E160D/E160D) mice develop a considerably elevated incidence of B-cell lymphomas beginning at 6 months of age, particularly in females. By 16 months of age, more than 90% of the Fen1(E160D/E160D) females have tumors, primarily lymphomas. By contrast, Fen1(DeltaPCNA/DeltaPCNA) mouse embryos show extensive apoptosis in the forebrain and vertebrae area and die around stage E9.5 to E11.5.

Identification of biochemical adaptations in hyper- or hypocontractile hearts from phospholamban mutant mice by expression proteomics.

PubMed

Pan, Yan; Kislinger, Thomas; Gramolini, Anthony O; Zvaritch, Elena; Kranias, Evangelia G; MacLennan, David H; Emili, Andrew

2004-02-24

Phospholamban (PLN) is a critical regulator of cardiac contractility through its binding to and regulation of the activity of the sarco(endo)plasmic reticulum Ca2+ ATPase. To uncover biochemical adaptations associated with extremes of cardiac muscle contractility, we used high-throughput gel-free tandem MS to monitor differences in the relative abundance of membrane proteins in standard microsomal fractions isolated from the hearts of PLN-null mice (PLN-KO) with high contractility and from transgenic mice overexpressing a superinhibitory PLN mutant in a PLN-null background (I40A-KO) with diminished contractility. Significant differential expression was detected for a subset of the 782 proteins identified, including known membrane-associated biomarkers, components of signaling pathways, and previously uninvestigated proteins. Proteins involved in fat and carbohydrate metabolism and proteins linked to G protein-signaling pathways activating protein kinase C were enriched in I40A-KO cardiac muscle, whereas proteins linked to enhanced contractile function were enriched in PLN-KO mutant hearts. These data demonstrate that Ca2+ dysregulation, leading to elevated or depressed cardiac contractility, induces compensatory biochemical responses.

Dominant negative DISC1 mutant mice display specific social behaviour deficits and aberration in BDNF and cannabinoid receptor expression.

PubMed

Kaminitz, Ayelet; Barzilay, Ran; Segal, Hadar; Taler, Michal; Offen, Daniel; Gil-Ad, Irit; Mechoulam, Raphael; Weizman, Abraham

2014-01-01

OBJECTIVES. Disrupted in schizophrenia 1 (DISC1) is considered the most prominent candidate gene for schizophrenia. In this study, we aimed to characterize behavioural and brain biochemical traits in a mouse expressing a dominant negative DISC1mutant (DN-DISC1). DN-DISC1 mice underwent behavioural tests to evaluate object recognition, social preference and social novelty seeking. ELISA was conducted on brain tissue to evaluate BDNF levels. Western blot was employed to measure BDNF receptor (TrkB) and cannabinoid receptor CB1. The mutant DISC1 mice displayed deficits in preference to social novelty while both social preference and object recognition were intact. Biochemical analysis of prefrontal cortex and hippocampus revealed a modest reduction in cortical TrkB protein levels of male mice while no differences in BDNF levels were observed. We found sex dependent differences in the expression of cannabinoid-1 receptors. We describe novel behavioural and biochemical abnormalities in the DN-DISC1 mouse model of schizophrenia. The data shows for the first time a possible link between DISC1 mutation and the cannabinoid system.

ATM loss leads to synthetic lethality in BRCA1 BRCT mutant mice associated with exacerbated defects in homology-directed repair

PubMed Central

Chen, Chun-Chin; Kass, Elizabeth M.; Yen, Wei-Feng; Ludwig, Thomas; Moynahan, Mary Ellen; Chaudhuri, Jayanta; Jasin, Maria

2017-01-01

BRCA1 is essential for homology-directed repair (HDR) of DNA double-strand breaks in part through antagonism of the nonhomologous end-joining factor 53BP1. The ATM kinase is involved in various aspects of DNA damage signaling and repair, but how ATM participates in HDR and genetically interacts with BRCA1 in this process is unclear. To investigate this question, we used the Brca1S1598F mouse model carrying a mutation in the BRCA1 C-terminal domain of BRCA1. Whereas ATM loss leads to a mild HDR defect in adult somatic cells, we find that ATM inhibition leads to severely reduced HDR in Brca1S1598F cells. Consistent with a critical role for ATM in HDR in this background, loss of ATM leads to synthetic lethality of Brca1S1598F mice. Whereas both ATM and BRCA1 promote end resection, which can be regulated by 53BP1, 53bp1 deletion does not rescue the HDR defects of Atm mutant cells, in contrast to Brca1 mutant cells. These results demonstrate that ATM has a role in HDR independent of the BRCA1–53BP1 antagonism and that its HDR function can become critical in certain contexts. PMID:28659469

ATM loss leads to synthetic lethality in BRCA1 BRCT mutant mice associated with exacerbated defects in homology-directed repair.

PubMed

Chen, Chun-Chin; Kass, Elizabeth M; Yen, Wei-Feng; Ludwig, Thomas; Moynahan, Mary Ellen; Chaudhuri, Jayanta; Jasin, Maria

2017-07-18

BRCA1 is essential for homology-directed repair (HDR) of DNA double-strand breaks in part through antagonism of the nonhomologous end-joining factor 53BP1. The ATM kinase is involved in various aspects of DNA damage signaling and repair, but how ATM participates in HDR and genetically interacts with BRCA1 in this process is unclear. To investigate this question, we used the Brca1 S1598F mouse model carrying a mutation in the BRCA1 C-terminal domain of BRCA1. Whereas ATM loss leads to a mild HDR defect in adult somatic cells, we find that ATM inhibition leads to severely reduced HDR in Brca1 S1598F cells. Consistent with a critical role for ATM in HDR in this background, loss of ATM leads to synthetic lethality of Brca1 S1598F mice. Whereas both ATM and BRCA1 promote end resection, which can be regulated by 53BP1, 53bp1 deletion does not rescue the HDR defects of Atm mutant cells, in contrast to Brca1 mutant cells. These results demonstrate that ATM has a role in HDR independent of the BRCA1-53BP1 antagonism and that its HDR function can become critical in certain contexts.

Serotonin hyperinnervation and upregulated 5-HT2A receptor expression and motor-stimulating function in nigrostriatal dopamine-deficient Pitx3 mutant mice.

PubMed

Li, Li; Qiu, Guozhen; Ding, Shengyuan; Zhou, Fu-Ming

2013-01-23

The striatum receives serotonin (5-hydroxytryptamine, 5-HT) innervation and expresses 5-HT2A receptors (5-HT2ARs) and other 5-HT receptors, raising the possibility that the striatal 5-HT system may undergo adaptive changes after chronic severe dopamine (DA) loss and contribute to the function and dysfunction of the striatum. Here we show that in transcription factor Pitx3 gene mutant mice with a selective, severe DA loss in the dorsal striatum mimicking the DA denervation in late Parkinson's disease (PD), both the 5-HT innervation and the 5-HT2AR mRNA expression were increased in the dorsal striatum. Functionally, while having no detectable motor effect in wild type mice, the 5-HT2R agonist 2,5-dimethoxy-4-iodoamphetamine increased both the baseline and l-dopa-induced normal ambulatory and dyskinetic movements in Pitx3 mutant mice, whereas the selective 5-HT2AR blocker volinanserin had the opposite effects. These results demonstrate that Pitx3 mutant mice are a convenient and valid mouse model to study the compensatory 5-HT upregulation following the loss of the nigrostriatal DA projection and that the upregulated 5-HT2AR function in the DA deficient dorsal striatum may enhance both normal and dyskinetic movements. Copyright © 2012 Elsevier B.V. All rights reserved.

Irxl1 mutant mice show reduced tendon differentiation and no patterning defects in musculoskeletal system development.

PubMed

Kimura, Wataru; Machii, Masashi; Xue, XiaoDong; Sultana, Nishat; Hikosaka, Keisuke; Sharkar, Mohammad T K; Uezato, Tadayoshi; Matsuda, Masashi; Koseki, Haruhiko; Miura, Naoyuki

2011-01-01

Irxl1 (Iroquois-related homeobox like-1) is a newly identified three amino-acid loop extension (TALE) homeobox gene, which is expressed in various mesoderm-derived tissues, particularly in the progenitors of the musculoskeletal system. To analyze the roles of Irxl1 during embryonic development, we generated mice carrying a null allele of Irxl1. Mice homozygous for the targeted allele were viable, fertile, and showed reduced tendon differentiation. Skeletal morphology and skeletal muscle weight in Irxl1-knockout mice appeared normal. Expression patterns of several marker genes for cartilage, tendon, and muscle progenitors in homozygous mutant embryos were unchanged. These results suggest that Irxl1 is required for the tendon differentiation but dispensable for the patterning of the musculoskeletal system in development. Copyright © 2010 Wiley-Liss, Inc.

Knockout of Foxp2 disrupts vocal development in mice

PubMed Central

Castellucci, Gregg A.; McGinley, Matthew J.; McCormick, David A.

2016-01-01

The FOXP2 gene is important for the development of proper speech motor control in humans. However, the role of the gene in general vocal behavior in other mammals, including mice, is unclear. Here, we track the vocal development of Foxp2 heterozygous knockout (Foxp2+/−) mice and their wildtype (WT) littermates from juvenile to adult ages, and observe severe abnormalities in the courtship song of Foxp2+/− mice. In comparison to their WT littermates, Foxp2+/− mice vocalized less, produced shorter syllable sequences, and possessed an abnormal syllable inventory. In addition, Foxp2+/− song also exhibited irregular rhythmic structure, and its development did not follow the consistent trajectories observed in WT vocalizations. These results demonstrate that the Foxp2 gene is critical for normal vocal behavior in juvenile and adult mice, and that Foxp2 mutant mice may provide a tractable model system for the study of the gene’s role in general vocal motor control. PMID:26980647

Knockout of Foxp2 disrupts vocal development in mice.

PubMed

Castellucci, Gregg A; McGinley, Matthew J; McCormick, David A

2016-03-16

The FOXP2 gene is important for the development of proper speech motor control in humans. However, the role of the gene in general vocal behavior in other mammals, including mice, is unclear. Here, we track the vocal development of Foxp2 heterozygous knockout (Foxp2+/-) mice and their wildtype (WT) littermates from juvenile to adult ages, and observe severe abnormalities in the courtship song of Foxp2+/- mice. In comparison to their WT littermates, Foxp2+/- mice vocalized less, produced shorter syllable sequences, and possessed an abnormal syllable inventory. In addition, Foxp2+/- song also exhibited irregular rhythmic structure, and its development did not follow the consistent trajectories observed in WT vocalizations. These results demonstrate that the Foxp2 gene is critical for normal vocal behavior in juvenile and adult mice, and that Foxp2 mutant mice may provide a tractable model system for the study of the gene's role in general vocal motor control.

Microglial K+ Channel Expression in Young Adult and Aged Mice

PubMed Central

Schilling, Tom; Eder, Claudia

2015-01-01

The K+ channel expression pattern of microglia strongly depends on the cells' microenvironment and has been recognized as a sensitive marker of the cells' functional state. While numerous studies have been performed on microglia in vitro, our knowledge about microglial K+ channels and their regulation in vivo is limited. Here, we have investigated K+ currents of microglia in striatum, neocortex and entorhinal cortex of young adult and aged mice. Although almost all microglial cells exhibited inward rectifier K+ currents upon membrane hyperpolarization, their mean current density was significantly enhanced in aged mice compared with that determined in young adult mice. Some microglial cells additionally exhibited outward rectifier K+ currents in response to depolarizing voltage pulses. In aged mice, microglial outward rectifier K+ current density was significantly larger than in young adult mice due to the increased number of aged microglial cells expressing these channels. Aged dystrophic microglia exhibited outward rectifier K+ currents more frequently than aged ramified microglia. The majority of microglial cells expressed functional BK-type, but not IK- or SK-type, Ca2+-activated K+ channels, while no differences were found in their expression levels between microglia of young adult and aged mice. Neither microglial K+ channel pattern nor K+ channel expression levels differed markedly between the three brain regions investigated. It is concluded that age-related changes in microglial phenotype are accompanied by changes in the expression of microglial voltage-activated, but not Ca2+-activated, K+ channels. PMID:25472417

Otx1 null mutant mice show partial segregation of sensory epithelia comparable to lamprey ears

NASA Technical Reports Server (NTRS)

Fritzsch, B.; Signore, M.; Simeone, A.

2001-01-01

We investigated the development of inner ear innervation in Otx1 null mutants, which lack a horizontal canal, between embryonic day 12 (E12) and postnatal day 7 (P7) with DiI and immunostaining for acetylated tubulin. Comparable to control animals, horizontal crista-like fibers were found to cross over the utricle in Otx1 null mice. In mutants these fibers extend toward an area near the endolymphatic duct, not to a horizontal crista. Most Otx1 null mutants had a small patch of sensory hair cells at this position. Measurement of the area of the utricular macula suggested it to be enlarged in Otx1 null mutants. We suggest that parts of the horizontal canal crista remain incorporated in the utricular sensory epithelium in Otx1 null mutants. Other parts of the horizontal crista appear to be variably segregated to form the isolated patch of hair cells identifiable by the unique fiber trajectory as representing the horizontal canal crista. Comparison with lamprey ear innervation reveals similarities in the pattern of innervation with the dorsal macula, a sensory patch of unknown function. SEM data confirm that all foramina are less constricted in Otx1 null mutants. We propose that Otx1 is not directly involved in sensory hair cell formation of the horizontal canal but affects the segregation of the horizontal canal crista from the utricle. It also affects constriction of the two main foramina in the ear, but not their initial formation. Otx1 is thus causally related to horizontal canal morphogenesis as well as morphogenesis of these foramina.

The Tennessee Mouse Genome Consortium: Identification of ocular mutants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jablonski, Monica M.; Wang, Xiaofei; Lu, Lu

2005-06-01

The Tennessee Mouse Genome Consortium (TMGC) is in its fifth year of a ethylnitrosourea (ENU)-based mutagenesis screen to detect recessive mutations that affect the eye and brain. Each pedigree is tested by various phenotyping domains including the eye, neurohistology, behavior, aging, ethanol, drug, social behavior, auditory, and epilepsy domains. The utilization of a highly efficient breeding protocol and coordination of various universities across Tennessee makes it possible for mice with ENU-induced mutations to be evaluated by nine distinct phenotyping domains within this large-scale project known as the TMGC. Our goal is to create mutant lines that model human diseases andmore » disease syndromes and to make the mutant mice available to the scientific research community. Within the eye domain, mice are screened for anterior and posterior segment abnormalities using slit-lamp biomicroscopy, indirect ophthalmoscopy, fundus photography, eye weight, histology, and immunohistochemistry. As of January 2005, we have screened 958 pedigrees and 4800 mice, excluding those used in mapping studies. We have thus far identified seven pedigrees with primary ocular abnormalities. Six of the mutant pedigrees have retinal or subretinal aberrations, while the remaining pedigree presents with an abnormal eye size. Continued characterization of these mutant mice should in most cases lead to the identification of the mutated gene, as well as provide insight into the function of each gene. Mice from each of these pedigrees of mutant mice are available for distribution to researchers for independent study.« less

Selective Ablation of Ctip2/Bcl11b in Epidermal Keratinocytes Triggers Atopic Dermatitis-Like Skin Inflammatory Responses in Adult Mice

PubMed Central

Guha, Gunjan; Li, Shan; Kyrylkova, Kateryna; Kioussi, Chrissa; Leid, Mark; Ganguli-Indra, Gitali; Indra, Arup K.

2012-01-01

Background Ctip2 is crucial for epidermal homeostasis and protective barrier formation in developing mouse embryos. Selective ablation of Ctip2 in epidermis leads to increased transepidermal water loss (TEWL), impaired epidermal proliferation, terminal differentiation, as well as altered lipid composition during development. However, little is known about the role of Ctip2 in skin homeostasis in adult mice. Methodology/Principal Findings To study the role of Ctip2 in adult skin homeostasis, we utilized Ctip2ep−/− mouse model in which Ctip2 is selectively deleted in epidermal keratinocytes. Measurement of TEWL, followed by histological, immunohistochemical, and RT-qPCR analyses revealed an important role of Ctip2 in barrier maintenance and in regulating adult skin homeostasis. We demonstrated that keratinocytic ablation of Ctip2 leads to atopic dermatitis (AD)-like skin inflammation, characterized by alopecia, pruritus and scaling, as well as extensive infiltration of immune cells including T lymphocytes, mast cells, and eosinophils. We observed increased expression of T-helper 2 (Th2)-type cytokines and chemokines in the mutant skin, as well as systemic immune responses that share similarity with human AD patients. Furthermore, we discovered that thymic stromal lymphopoietin (TSLP) expression was significantly upregulated in the mutant epidermis as early as postnatal day 1 and ChIP assay revealed that TSLP is likely a direct transcriptional target of Ctip2 in epidermal keratinocytes. Conclusions/Significance Our data demonstrated a cell-autonomous role of Ctip2 in barrier maintenance and epidermal homeostasis in adult mice skin. We discovered a crucial non-cell autonomous role of keratinocytic Ctip2 in suppressing skin inflammatory responses by regulating the expression of Th2-type cytokines. It is likely that the epidermal hyperproliferation in the Ctip2-lacking epidermis may be secondary to the compensatory response of the adult epidermis that is defective in

Maternal nicotine exposure effects on adolescent learning and memory are abolished in alpha(α)2* nicotinic acetylcholine receptor-null mutant mice.

PubMed

Mojica, Celina; Bai, Yu; Lotfipour, Shahrdad

2018-06-01

The objective of the current study is to test the hypothesis that the deletion of alpha(α)2* nicotinic acetylcholine receptors (nAChRs) (encoded by the Chrna2 gene) ablate maternal nicotine-induced learning and memory deficits in adolescent mice. We use a pre-exposure-dependent contextual fear conditioning behavioral paradigm that is highly hippocampus-dependent. Adolescent wild type and α2-null mutant offspring are exposed to vehicle or maternal nicotine exposure (200 μg/ml, expressed as base) in the drinking water throughout pregnancy until weaning. Adolescent male offspring mice are tested for alterations in growth and development characteristics as well as modifications in locomotion, anxiety, shock-reactivity and learning and memory. As expected, maternal nicotine exposure has no effects on pup number, weight gain and only modestly reduces fluid intake by 19%. Behaviorally, maternal nicotine exposure impedes extinction learning in adolescent wild type mice, a consequence that is abolished in α2-null mutant mice. The effects on learning and memory are not confounded by alternations in stereotypy, locomotion, anxiety or sensory shock reactivity. Overall, the findings highlight that the deletion of α2* nAChRs eliminate the effects of maternal nicotine exposure on learning and memory in adolescent mice. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hip1-related mutant mice grow and develop normally but have accelerated spinal abnormalities and dwarfism in the absence of HIP1.

PubMed

Hyun, Teresa S; Li, Lina; Oravecz-Wilson, Katherine I; Bradley, Sarah V; Provot, Melissa M; Munaco, Anthony J; Mizukami, Ikuko F; Sun, Hanshi; Ross, Theodora S

2004-05-01

In mice and humans, there are two known members of the Huntingtin interacting protein 1 (HIP1) family, HIP1 and HIP1-related (HIP1r). Based on structural and functional data, these proteins participate in the clathrin trafficking network. The inactivation of Hip1 in mice leads to spinal, hematopoietic, and testicular defects. To investigate the biological function of HIP1r, we generated a Hip1r mutant allele in mice. Hip1r homozygous mutant mice are viable and fertile without obvious morphological abnormalities. In addition, embryonic fibroblasts derived from these mice do not have gross abnormalities in survival, proliferation, or clathrin trafficking pathways. Altogether, this demonstrates that HIP1r is not necessary for normal development of the embryo or for normal adulthood and suggests that HIP1 or other functionally related members of the clathrin trafficking network can compensate for HIP1r absence. To test the latter, we generated mice deficient in both HIP1 and HIP1r. These mice have accelerated development of abnormalities seen in Hip1 -deficient mice, including kypholordosis and growth defects. The severity of the Hip1r/Hip1 double-knockout phenotype compared to the Hip1 knockout indicates that HIP1r partially compensates for HIP1 function in the absence of HIP1 expression, providing strong evidence that HIP1 and HIP1r have overlapping roles in vivo.

Vaccination with plasmid DNA encoding a mutant toxic shock syndrome toxin-1 ameliorates toxin-induced lethal shock in mice.

PubMed

Feng, Mao-Hui; Cui, Jing-Chun; Nakane, Akio; Hu, Dong-Liang

2013-09-01

Staphylococcal toxic shock syndrome toxin-1 (TSST-1), a superantigenic toxin produced by Staphylococcus (S.) aureus, is a major cause of septic shock and toxic shock syndrome. To investigate whether vaccination with a plasmid DNA encoding a non-toxic mutant TSST-1 (mTSST-1) can protect mice against wild-type TSST-1-induced lethal shock, the mice were intranasally immunized with the plasmid DNA (named pcDNA-mTSST-1) plus a mucosal adjuvant, a non-toxic mutant labile toxin (mLT). After the immunization, the mice were challenged with TSST-1 and lipopolysaccharide (LPS). The survival rate of mice immunized with pcDNA-mTSST-1 plus mLT was higher than that of the control mice immunized with PBS alone, mLT alone, pcDNA-mTSST-1 alone, or a parent plasmid plus mLT. The titers of interferon-γ (IFN-γ) in the sera of mice immunized with pcDNA-mTSST-1 plus mLT were significantly lower than those of the mLT control mice. Immunization with pcDNA-mTSST-1 plus mLT increased the serum levels of TSST-1-specific antibodies, especially immunoglobulin G1 (IgG1) and IgG2a subclasses. Furthermore, the sera obtained from mice immunized with pcDNA-mTSST-1 plus mLT significantly inhibited the TSST-1-induced secretion of IFN-γ and tumor necrosis factor-α (TNF-α) in murine spleen cells in vitro. These results indicate that immunization with pcDNA-mTSST-1 plus mLT provides protection against the lethal toxic shock of mice induced by wild-type TSST-1. The protective effect could be due to TSST-1-specific neutralizing antibodies as well as the inhibition of IFN-γ and TNF-α secretions. Since TSST-1 is commonly released by invasive S. aureus, the pcDNA-mTSST-1 should be useful in preventing toxin-induced shock resulting from S. aureus infection.

The cleft lip and palate defects in Dancer mutant mice result from gain of function of the Tbx10 gene

PubMed Central

Bush, Jeffrey O.; Lan, Yu; Jiang, Rulang

2004-01-01

Cleft lip and palate (CL/P) is a common disfiguring birth defect with complex, poorly understood etiology. Mice carrying a spontaneous mutation, Dancer (Dc), exhibit CL/P in homozygotes and show significantly increased susceptibility to CL/P in heterozygotes [Deol, M. S. & Lane, P. W. (1966) J. Embryol. Exp. Morphol. 16, 543–558 and Trasler, D. G., Kemp, D. & Trasler, T. A. (1984) Teratology 29, 101–104], providing an animal model for understanding the molecular pathogenesis of CL/P. We genetically mapped Dc to within a 1-cM region near the centromere of chromosome 19. In situ hybridization analysis showed that one positional candidate gene, Tbx10, is ectopically expressed in Dc mutant embryos. Positional cloning of the Dc locus revealed an insertion of a 3.3-kb sequence containing the 5′ region of the p23 gene into the first intron of Tbx10, which causes ectopic expression of a p23-Tbx10 chimeric transcript encoding a protein product identical to a normal variant of the Tbx10 protein. Furthermore, we show that ectopic expression of Tbx10 in transgenic mice recapitulates the Dc mutant phenotype, indicating that CL/Pin Dc mutant mice results from the p23 insertion-induced ectopic Tbx10 expression. These results identify gain of function of a T-box transcription factor gene as a mechanism underlying CL/P pathogenesis. PMID:15118109

Perinatal DDT Exposure Induces Hypertension and Cardiac Hypertrophy in Adult Mice.

PubMed

La Merrill, Michele A; Sethi, Sunjay; Benard, Ludovic; Moshier, Erin; Haraldsson, Borje; Buettner, Christoph

2016-11-01

Dichlorodiphenyltrichloroethane (DDT) was used extensively to control malaria, typhus, body lice, and bubonic plague worldwide, until countries began restricting its use in the 1970s. However, the use of DDT to control vector-borne diseases continues in developing countries. Prenatal DDT exposure is associated with elevated blood pressure in humans. We hypothesized that perinatal DDT exposure causes hypertension in adult mice. DDT was administered to C57BL/6J dams from gestational day 11.5 to postnatal day 5. Blood pressure (BP) and myocardial wall thickness were measured in male and female adult offspring. Adult mice were treated with an angiotensin converting enzyme (ACE) inhibitor, captopril, to evaluate sensitivity to amelioration of DDT-associated hypertension by ACE inhibition. We further assessed the influence of DDT exposure on the expression of mRNAs that regulate BP through renal ion transport. Adult mice perinatally exposed to DDT exhibited chronically increased systolic BP, increased myocardial wall thickness, and elevated expression of mRNAs of several renal ion transporters. Captopril completely reversed hypertension in mice perinatally exposed to DDT. These data demonstrate that perinatal exposure to DDT causes hypertension and cardiac hypertrophy in adult offspring. A key mechanism underpinning this hypertension is an overactivated renin angiotensin system because ACE inhibition reverses the hypertension induced by perinatal DDT exposure. Citation: La Merrill M, Sethi S, Benard L, Moshier E, Haraldsson B, Buettner C. 2016. Perinatal DDT exposure induces hypertension and cardiac hypertrophy in adult mice. Environ Health Perspect 124:1722-1727; http://dx.doi.org/10.1289/EHP164.

Impaired fear extinction learning in adult heterozygous BDNF knock-out mice.

PubMed

Psotta, Laura; Lessmann, Volkmar; Endres, Thomas

2013-07-01

Brain-derived neurotrophic factor (BDNF) is a crucial regulator of neuroplasticity, which underlies learning and memory processes in different brain areas. To investigate the role of BDNF in the extinction of amygdala-dependent cued fear memories, we analyzed fear extinction learning in heterozygous BDNF knock-out mice, which possess a reduction of endogenous BDNF protein levels to ~50% of wild-type animals. Since BDNF expression has been shown to decline with aging of animals, we tested the performance in extinction learning of these mice at 2 months (young adults) and 7 months (older adults) of age. The present study shows that older adult heterozygous BDNF knock-out mice, which have a chronic 50% lack of BDNF, also possess a deficit in the acquisition of extinction memory, while extinction learning remains unaffected in young adult heterozygous BDNF knock-out mice. This deficit in extinction learning is accompanied by a reduction of BDNF protein in the hippocampus, amygdala and the prefrontal cortex. Copyright © 2013 Elsevier Inc. All rights reserved.

Production and characterization of streptomycin dependent mutants of Pasteurella multocida from bovine haemorrhagic septicaemia.

PubMed Central

de Alwis, M C; Carter, G R; Chengappa, M M

1980-01-01

A large number of streptomycin dependent mutants were produced from bovine haemorrhagic septicaemia strains of Pasteurella multocida. The mutants required a minimum concentration of 25-50 microgram/mL streptomycin for growth and tolerated a concentration of 200 mg/mL. These mutants were avirulent to mice, when inoculated alone, but some mutants killed mice when inoculated with streptomycin. Biochemically all mutants were uniform and similar to the wild type. Most mutants were stable, but a few produced streptomycin independent revertants. The rate of reversion varied with each mutant. Most revertants were highly virulent for mice, some totally avirulant and a few relatively avirulent. PMID:6778598

Wt1 dictates the fate of fetal and adult Leydig cells during development in the mouse testis.

PubMed

Wen, Qing; Zheng, Qiao-Song; Li, Xi-Xia; Hu, Zhao-Yuan; Gao, Fei; Cheng, C Yan; Liu, Yi-Xun

2014-12-15

Wilms' tumor 1 (Wt1) is a tumor suppressor gene encoding ∼24 zinc finger transcription factors. In the mammalian testis, Wt1 is expressed mostly by Sertoli cells (SCs) involved in testis development, spermatogenesis, and adult Leydig cell (ALC) steroidogenesis. Global knockout (KO) of Wt1 is lethal in mice due to defects in embryogenesis. Herein, we showed that Wt1 is involved in regulating fetal Leydig cell (FLC) degeneration and ALC differentiation during testicular development. Using Wt1(-/flox);Amh-Cre mice that specifically deleted Wt1 in the SC vs. age-matched wild-type (WT) controls, FLC-like-clusters were found in Wt1-deficient testes that remained mitotically active from postnatal day 1 (P1) to P56, and no ALC was detected at these ages. Leydig cells in mutant adult testes displayed morphological features of FLC. Also, FLC-like cells in adult mutant testes had reduced expression in ALC-associated genes Ptgds, Sult1e1, Vcam1, Hsd11b1, Hsd3b6, and Hsd17b3 but high expression of FLC-associated genes Thbs2 and Hsd3b1. Whereas serum LH and testosterone level in mutant mice were not different from controls, intratesticular testosterone level was significantly reduced. Deletion of Wt1 gene also perturbed the expression of steroidogenic enzymes Star, P450c17, Hsd3b6, Hsd3b1, Hsd17b1, and Hsd17b3. FLCs in adult mutant testes failed to convert androstenedione to testosterone due to a lack of Hsd17b3, and this defect was rescued by coculturing with fetal SCs. In summary, FLC-like cells in mutant testes are putative FLCs that remain mitotically active in adult mice, illustrating that Wt1 dictates the fate of FLC and ALC during postnatal testis development. Copyright © 2014 the American Physiological Society.

Primary Coenzyme Q Deficiency in Pdss2 Mutant Mice Causes Isolated Renal Disease

PubMed Central

Haase, Volker H.; King, Rhonda; Polyak, Erzsebet; Selak, Mary; Yudkoff, Marc; Hancock, Wayne W.; Meade, Ray; Saiki, Ryoichi; Lunceford, Adam L.; Clarke, Catherine F.; Gasser, David L.

2008-01-01

Coenzyme Q (CoQ) is an essential electron carrier in the respiratory chain whose deficiency has been implicated in a wide variety of human mitochondrial disease manifestations. Its multi-step biosynthesis involves production of polyisoprenoid diphosphate in a reaction that requires the enzymes be encoded by PDSS1 and PDSS2. Homozygous mutations in either of these genes, in humans, lead to severe neuromuscular disease, with nephrotic syndrome seen in PDSS2 deficiency. We now show that a presumed autoimmune kidney disease in mice with the missense Pdss2kd/kd genotype can be attributed to a mitochondrial CoQ biosynthetic defect. Levels of CoQ9 and CoQ10 in kidney homogenates from B6.Pdss2kd/kd mutants were significantly lower than those in B6 control mice. Disease manifestations originate specifically in glomerular podocytes, as renal disease is seen in Podocin/cre,Pdss2loxP/loxP knockout mice but not in conditional knockouts targeted to renal tubular epithelium, monocytes, or hepatocytes. Liver-conditional B6.Alb/cre,Pdss2loxP/loxP knockout mice have no overt disease despite demonstration that their livers have undetectable CoQ9 levels, impaired respiratory capacity, and significantly altered intermediary metabolism as evidenced by transcriptional profiling and amino acid quantitation. These data suggest that disease manifestations of CoQ deficiency relate to tissue-specific respiratory capacity thresholds, with glomerular podocytes displaying the greatest sensitivity to Pdss2 impairment. PMID:18437205

Hip1-related Mutant Mice Grow and Develop Normally but Have Accelerated Spinal Abnormalities and Dwarfism in the Absence of HIP1†

PubMed Central

Hyun, Teresa S.; Li, Lina; Oravecz-Wilson, Katherine I.; Bradley, Sarah V.; Provot, Melissa M.; Munaco, Anthony J.; Mizukami, Ikuko F.; Sun, Hanshi; Ross, Theodora S.

2004-01-01

In mice and humans, there are two known members of the Huntingtin interacting protein 1 (HIP1) family, HIP1 and HIP1-related (HIP1r). Based on structural and functional data, these proteins participate in the clathrin trafficking network. The inactivation of Hip1 in mice leads to spinal, hematopoietic, and testicular defects. To investigate the biological function of HIP1r, we generated a Hip1r mutant allele in mice. Hip1r homozygous mutant mice are viable and fertile without obvious morphological abnormalities. In addition, embryonic fibroblasts derived from these mice do not have gross abnormalities in survival, proliferation, or clathrin trafficking pathways. Altogether, this demonstrates that HIP1r is not necessary for normal development of the embryo or for normal adulthood and suggests that HIP1 or other functionally related members of the clathrin trafficking network can compensate for HIP1r absence. To test the latter, we generated mice deficient in both HIP1 and HIP1r. These mice have accelerated development of abnormalities seen in Hip1 -deficient mice, including kypholordosis and growth defects. The severity of the Hip1r/Hip1 double-knockout phenotype compared to the Hip1 knockout indicates that HIP1r partially compensates for HIP1 function in the absence of HIP1 expression, providing strong evidence that HIP1 and HIP1r have overlapping roles in vivo. PMID:15121852

Perinatal DDT Exposure Induces Hypertension and Cardiac Hypertrophy in Adult Mice

PubMed Central

La Merrill, Michele A.; Sethi, Sunjay; Benard, Ludovic; Moshier, Erin; Haraldsson, Borje; Buettner, Christoph

2016-01-01

Background: Dichlorodiphenyltrichloroethane (DDT) was used extensively to control malaria, typhus, body lice, and bubonic plague worldwide, until countries began restricting its use in the 1970s. However, the use of DDT to control vector-borne diseases continues in developing countries. Prenatal DDT exposure is associated with elevated blood pressure in humans. Objective: We hypothesized that perinatal DDT exposure causes hypertension in adult mice. Methods: DDT was administered to C57BL/6J dams from gestational day 11.5 to postnatal day 5. Blood pressure (BP) and myocardial wall thickness were measured in male and female adult offspring. Adult mice were treated with an angiotensin converting enzyme (ACE) inhibitor, captopril, to evaluate sensitivity to amelioration of DDT-associated hypertension by ACE inhibition. We further assessed the influence of DDT exposure on the expression of mRNAs that regulate BP through renal ion transport. Results: Adult mice perinatally exposed to DDT exhibited chronically increased systolic BP, increased myocardial wall thickness, and elevated expression of mRNAs of several renal ion transporters. Captopril completely reversed hypertension in mice perinatally exposed to DDT. Conclusions: These data demonstrate that perinatal exposure to DDT causes hypertension and cardiac hypertrophy in adult offspring. A key mechanism underpinning this hypertension is an overactivated renin angiotensin system because ACE inhibition reverses the hypertension induced by perinatal DDT exposure. Citation: La Merrill M, Sethi S, Benard L, Moshier E, Haraldsson B, Buettner C. 2016. Perinatal DDT exposure induces hypertension and cardiac hypertrophy in adult mice. Environ Health Perspect 124:1722–1727; http://dx.doi.org/10.1289/EHP164 PMID:27325568

Effects of dietary restriction on the expression of insulin-signaling-related genes in long-lived mutant mice.

PubMed

Bartke, Andrzej; Masternak, Michal M; Al-Regaiey, Khalid A; Bonkowski, Michael S

2007-01-01

Hypopituitary Ames dwarf mice and growth-hormone-resistant (growth hormone receptor knockout, GHRKO) mice have reduced plasma levels of insulin-like growth factor 1 and insulin, enhanced insulin sensitivity and a remarkably increased life span. This resembles the phenotypic characteristics of genetically normal animals subjected to dietary restriction (DR). Interestingly, DR leads to further increases in insulin sensitivity and longevity in Ames dwarfs but not in GHRKO mice. It was therefore of interest to examine the effects of DR on the expression of insulin-related genes in these two types of long-lived mutant mice. The effects of DR partially overlapped but did not duplicate the effects of Ames dwarfism or GHR deletion on the expression of genes related to insulin signaling and cell responsiveness to insulin. Moreover, the effects of DR on the expression of the examined genes in different insulin target organs were not identical. Some of the insulin-related genes were similarly affected by DR in both GHRKO and normal mice, some were affected only in GHRKO mice and some only in normal animals. This last category is of particular interest since genes affected in normal but not GHRKO mice may be related to mechanisms by which DR extends longevity.

Over-Expression of Porcine Myostatin Missense Mutant Leads to A Gender Difference in Skeletal Muscle Growth between Transgenic Male and Female Mice.

PubMed

Ma, Dezun; Gao, Pengfei; Qian, Lili; Wang, Qingqing; Cai, Chunbo; Jiang, Shengwang; Xiao, Gaojun; Cui, Wentao

2015-08-24

Myostatin, a transforming growth factor-β family member, is a negative regulator of skeletal muscle development and growth. Piedmontese cattle breeds have a missense mutation, which results in a cysteine to tyrosine substitution in the mature myostatin protein (C313Y). This loss-of-function mutation in myostatin results in a double-muscled phenotype in cattle. Myostatin propeptide is an inhibitor of myostatin activity and is considered a potential agent to stimulate muscle growth in livestock. In this study, we generated transgenic mice overexpressing porcine myostatin missense mutant (pmMS), C313Y, and wild-type porcine myostatin propeptide (ppMS), respectively, to examine their effects on muscle growth in mice. Enhanced muscle growth was observed in both pmMS and ppMS transgenic female mice and also in ppMS transgenic male mice. However, there was no enhanced muscle growth observed in pmMS transgenic male mice. To explore why there is such a big difference in muscle growth between pmMS and ppMS transgenic male mice, the expression level of androgen receptor (AR) mutant AR45 was measured by Western blot. Results indicated that AR45 expression significantly increased in pmMS transgenic male mice while it decreased dramatically in ppMS transgenic male mice. Our data demonstrate that both pmMS and ppMS act as myostatin inhibitors in the regulation of muscle growth, but the effect of pmMS in male mice is reversed by an increased AR45 expression. These results provide useful insight and basic theory to future studies on improving pork quality by genetically manipulating myostatin expression or by regulating myostatin activity.

Persistence of polyomavirus in mice infected as adults differs from that observed in mice infected as newborns.

PubMed Central

Berke, Z; Dalianis, T

1993-01-01

By using the polymerase chain reaction (PCR) technique, a technique more sensitive than Southern analysis, which allows detection of polyomavirus DNA only in newborn and nude adult mice, it has now been possible to monitor the persistence pattern of polyomavirus DNA after infection of normal adult CBA mice for the first time. Viral signs appeared gradually, showing variations in time course and organ distribution between mice, and reached a peak activity after 2 to 3 weeks, when they could be found in bone, heart, gonads, lymph node, and skin, but disappeared by 2 to 5 months. No virus DNA was detected in the kidneys or lungs, which is in contrast to what is observed after infection of newborn mice. This finding suggests that the persistence pattern of polyomavirus is age dependent. PMID:8389934

Dissociation of spatial navigation and visual guidance performance in Purkinje cell degeneration (pcd) mutant mice.

PubMed

Goodlett, C R; Hamre, K M; West, J R

1992-04-10

Spatial learning in rodents requires normal functioning of hippocampal and cortical structures. Recent data suggest that the cerebellum may also be essential. Neurological mutant mice with dysgenesis of the cerebellum provide useful models to examine the effects of abnormal cerebellar function. Mice with one such mutation, Purkinje cell degeneration (pcd), in which Purkinje cells degenerate between the third and fourth postnatal weeks, were evaluated for performance of spatial navigation learning and visual guidance learning in the Morris maze swim-escape task. Unaffected littermates and C57BL/6J mice served as controls. Separate groups of pcd and control mice were tested at 30, 50 and 110 days of age. At all ages, pcd mice had severe deficits in distal-cue (spatial) navigation, failing to decrease path lengths over training and failing to express appropriate spatial biases on probe trials. On the proximal-cue (visual guidance) task, whenever performance differences between groups did occur, they were limited to the initial trials. The ability of the pcd mice to perform the proximal-cue but not the distal-cue task indicates that the massive spatial navigation deficit was not due simply to motor dysfunction. Histological evaluations confirmed that the pcd mutation resulted in Purkinje cell loss without significant depletion of cells in the hippocampal formation. These data provide further evidence that the cerebellum is vital for the expression of behavior directed by spatial cognitive processes.

Down regulation of miR-124 in both Werner syndrome DNA helicase mutant mice and mutant Caenorhabditis elegans wrn-1 reveals the importance of this microRNA in accelerated aging

PubMed Central

Dallaire, Alexandra; Garand, Chantal; Paquet, Eric R.; Mitchell, Sarah J.; de Cabo, Rafael; Simard, Martin J.

2012-01-01

Small non-coding microRNAs are believed to be involved in the mechanism of aging but nothing is known on the impact of microRNAs in the progeroid disorder Werner syndrome (WS). WS is a premature aging disorder caused by mutations in a RecQ-like DNA helicase. Mice lacking the helicase domain of the WRN ortholog exhibit many phenotypic features of WS, including a pro-oxidant status and a shorter mean life span. Caenorhabditis elegans (C. elegans) with a nonfunctional wrn-1 DNA helicase also exhibit a shorter life span. Thus, both models are relevant to study the expression of microRNAs involved in WS. In this study, we show that miR-124 expression is lost in the liver of Wrn helicase mutant mice. Interestingly, the expression of this conserved miR-124 in whole wrn-1 mutant worms is also significantly reduced. The loss of mir-124 in C. elegans increases reactive oxygen species formation and accumulation of the aging marker lipofuscin, reduces whole body ATP levels and results in a reduction in life span. Finally, supplementation of vitamin C normalizes the median life span of wrn-1 and mir-124 mutant worms. These results suggest that biological pathways involving WRN and miR-124 are conserved in the aging process across different species. PMID:23075628

Mice with mutant Inf2 show impaired podocyte and slit diaphragm integrity in response to protamine-induced kidney injury.

PubMed

Subramanian, Balajikarthick; Sun, Hua; Yan, Paul; Charoonratana, Victoria T; Higgs, Henry N; Wang, Fang; Lai, Ka-Man V; Valenzuela, David M; Brown, Elizabeth J; Schlöndorff, Johannes S; Pollak, Martin R

2016-08-01

Mutations in the INF2 (inverted formin 2) gene, encoding a diaphanous formin family protein that regulates actin cytoskeleton dynamics, cause human focal segmental glomerulosclerosis (FSGS). INF2 interacts directly with certain other mammalian diaphanous formin proteins (mDia) that function as RhoA effector molecules. FSGS-causing INF2 mutations impair these interactions and disrupt the ability of INF2 to regulate Rho/Dia-mediated actin dynamics in vitro. However, the precise mechanisms by which INF2 regulates and INF2 mutations impair glomerular structure and function remain unknown. Here, we characterize an Inf2 R218Q point-mutant (knockin) mouse to help answer these questions. Knockin mice have no significant renal pathology or proteinuria at baseline despite diminished INF2 protein levels. INF2 mutant podocytes do show impaired reversal of protamine sulfate-induced foot process effacement by heparin sulfate perfusion. This is associated with persistent podocyte cytoplasmic aggregation, nephrin phosphorylation, and nephrin and podocin mislocalization, as well as impaired recovery of mDia membrane localization. These changes were partially mimicked in podocyte outgrowth cultures, in which podocytes from knockin mice show altered cellular protrusions compared to those from wild-type mice. Thus, in mice, normal INF2 function is not required for glomerular development but normal INF2 is required for regulation of the actin-based behaviors necessary for response to and/or recovery from injury. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Mice mutant for glucokinase regulatory protein exhibit decreased liver glucokinase: A sequestration mechanism in metabolic regulation

PubMed Central

Farrelly, Dennis; Brown, Karen S.; Tieman, Aaron; Ren, Jianming; Lira, Sergio A.; Hagan, Deborah; Gregg, Richard; Mookhtiar, Kasim A.; Hariharan, Narayanan

1999-01-01

The importance of glucokinase (GK; EC 2.7.1.12) in glucose homeostasis has been demonstrated by the association of GK mutations with diabetes mellitus in humans and by alterations in glucose metabolism in transgenic and gene knockout mice. Liver GK activity in humans and rodents is allosterically inhibited by GK regulatory protein (GKRP). To further understand the role of GKRP in GK regulation, the mouse GKRP gene was inactivated. With the knockout of the GKRP gene, there was a parallel loss of GK protein and activity in mutant mouse liver. The loss was primarily because of posttranscriptional regulation of GK, indicating a positive regulatory role for GKRP in maintaining GK levels and activity. As in rat hepatocytes, both GK and GKRP were localized in the nuclei of mouse hepatocytes cultured in low-glucose-containing medium. In the presence of fructose or high concentrations of glucose, conditions known to relieve GK inhibition by GKRP in vitro, only GK was translocated into the cytoplasm. In the GKRP-mutant hepatocytes, GK was not found in the nucleus under any tested conditions. We propose that GKRP functions as an anchor to sequester and inhibit GK in the hepatocyte nucleus, where it is protected from degradation. This ensures that glucose phosphorylation is minimal when the liver is in the fasting, glucose-producing phase. This also enables the hepatocytes to rapidly mobilize GK into the cytoplasm to phosphorylate and store or metabolize glucose after the ingestion of dietary glucose. In GKRP-mutant mice, the disruption of this regulation and the subsequent decrease in GK activity leads to altered glucose metabolism and impaired glycemic control. PMID:10588736

Mice mutant for both Hoxa1 and Hoxb1 show extensive remodeling of the hindbrain and defects in craniofacial development.

PubMed

Rossel, M; Capecchi, M R

1999-11-01

The analysis of mice mutant for both Hoxa1 and Hoxb1 suggests that these two genes function together to pattern the hindbrain. Separately, mutations in Hoxa1 and Hoxb1 have profoundly different effects on hindbrain development. Hoxa1 mutations disrupt the rhombomeric organization of the hindbrain, whereas Hoxb1 mutations do not alter the rhombomeric pattern, but instead influence the fate of cells originating in rhombomere 4. We suggest that these differences are not the consequences of different functional roles for these gene products, but rather reflect differences in the kinetics of Hoxa1 and Hoxb1 gene expression. In strong support of the idea that Hoxa1 and Hoxb1 have overlapping functions, Hoxa1/Hoxb1 double mutant homozygotes exhibit a plethora of defects either not seen, or seen only in a very mild form, in mice mutant for only Hoxa1 or Hoxb1. Examples include: the loss of both rhombomeres 4 and 5, the selective loss of the 2(nd) branchial arch, and the loss of most, but not all, 2(nd) branchial arch-derived tissues. We suggest that the early role for both of these genes in hindbrain development is specification of rhombomere identities and that the aberrant development of the hindbrain in Hoxa1/Hoxb1 double mutants proceeds through two phases, the misspecification of rhombomeres within the hindbrain, followed subsequently by size regulation of the misspecified hindbrain through induction of apoptosis.

Skeletal development of mice lacking bone sialoprotein (BSP)--impairment of long bone growth and progressive establishment of high trabecular bone mass.

PubMed

Bouleftour, Wafa; Boudiffa, Maya; Wade-Gueye, Ndeye Marième; Bouët, Guénaëlle; Cardelli, Marco; Laroche, Norbert; Vanden-Bossche, Arnaud; Thomas, Mireille; Bonnelye, Edith; Aubin, Jane E; Vico, Laurence; Lafage-Proust, Marie Hélène; Malaval, Luc

2014-01-01

Adult Ibsp-knockout mice (BSP-/-) display shorter stature, lower bone turnover and higher trabecular bone mass than wild type, the latter resulting from impaired bone resorption. Unexpectedly, BSP knockout also affects reproductive behavior, as female mice do not construct a proper "nest" for their offsprings. Multiple crossing experiments nonetheless indicated that the shorter stature and lower weight of BSP-/- mice, since birth and throughout life, as well as their shorter femur and tibia bones are independent of the genotype of the mothers, and thus reflect genetic inheritance. In BSP-/- newborns, µCT analysis revealed a delay in membranous primary ossification, with wider cranial sutures, as well as thinner femoral cortical bone and lower tissue mineral density, reflected in lower expression of bone formation markers. However, trabecular bone volume and osteoclast parameters of long bones do not differ between genotypes. Three weeks after birth, osteoclast number and surface drop in the mutants, concomitant with trabecular bone accumulation. The growth plates present a thinner hypertrophic zone in newborns with lower whole bone expression of IGF-1 and higher IHH in 6 days old BSP-/- mice. At 3 weeks the proliferating zone is thinner and the hypertrophic zone thicker in BSP-/- than in BSP+/+ mice of either sex, maybe reflecting a combination of lower chondrocyte proliferation and impaired cartilage resorption. Six days old BSP-/- mice display lower osteoblast marker expression but higher MEPE and higher osteopontin(Opn)/Runx2 ratio. Serum Opn is higher in mutants at day 6 and in adults. Thus, lack of BSP alters long bone growth and membranous/cortical primary bone formation and mineralization. Endochondral development is however normal in mutant mice and the accumulation of trabecular bone observed in adults develops progressively in the weeks following birth. Compensatory high Opn may allow normal endochondral development in BSP-/- mice, while impairing

Normalizing the environment recapitulates adult human immune traits in laboratory mice.

PubMed

Beura, Lalit K; Hamilton, Sara E; Bi, Kevin; Schenkel, Jason M; Odumade, Oludare A; Casey, Kerry A; Thompson, Emily A; Fraser, Kathryn A; Rosato, Pamela C; Filali-Mouhim, Ali; Sekaly, Rafick P; Jenkins, Marc K; Vezys, Vaiva; Haining, W Nicholas; Jameson, Stephen C; Masopust, David

2016-04-28

Our current understanding of immunology was largely defined in laboratory mice, partly because they are inbred and genetically homogeneous, can be genetically manipulated, allow kinetic tissue analyses to be carried out from the onset of disease, and permit the use of tractable disease models. Comparably reductionist experiments are neither technically nor ethically possible in humans. However, there is growing concern that laboratory mice do not reflect relevant aspects of the human immune system, which may account for failures to translate disease treatments from bench to bedside. Laboratory mice live in abnormally hygienic specific pathogen free (SPF) barrier facilities. Here we show that standard laboratory mouse husbandry has profound effects on the immune system and that environmental changes produce mice with immune systems closer to those of adult humans. Laboratory mice--like newborn, but not adult, humans--lack effector-differentiated and mucosally distributed memory T cells. These cell populations were present in free-living barn populations of feral mice and pet store mice with diverse microbial experience, and were induced in laboratory mice after co-housing with pet store mice, suggesting that the environment is involved in the induction of these cells. Altering the living conditions of mice profoundly affected the cellular composition of the innate and adaptive immune systems, resulted in global changes in blood cell gene expression to patterns that more closely reflected the immune signatures of adult humans rather than neonates, altered resistance to infection, and influenced T-cell differentiation in response to a de novo viral infection. These data highlight the effects of environment on the basal immune state and response to infection and suggest that restoring physiological microbial exposure in laboratory mice could provide a relevant tool for modelling immunological events in free-living organisms, including humans.

Intramuscular Immunization of Mice with a Live-Attenuated Triple Mutant of Yersinia pestis CO92 Induces Robust Humoral and Cell-Mediated Immunity To Completely Protect Animals against Pneumonic Plague.

PubMed

Tiner, Bethany L; Sha, Jian; Ponnusamy, Duraisamy; Baze, Wallace B; Fitts, Eric C; Popov, Vsevolod L; van Lier, Christina J; Erova, Tatiana E; Chopra, Ashok K

2015-12-01

Earlier, we showed that the Δlpp ΔmsbB Δail triple mutant of Yersinia pestis CO92 with deleted genes encoding Braun lipoprotein (Lpp), an acyltransferase (MsbB), and the attachment invasion locus (Ail), respectively, was avirulent in a mouse model of pneumonic plague. In this study, we further evaluated the immunogenic potential of the Δlpp ΔmsbB Δail triple mutant and its derivative by different routes of vaccination. Mice were immunized via the subcutaneous (s.c.) or the intramuscular (i.m.) route with two doses (2 × 10(6) CFU/dose) of the above-mentioned triple mutant with 100% survivability of the animals. Upon subsequent pneumonic challenge with 70 to 92 50% lethal doses (LD(50)) of wild-type (WT) strain CO92, all of the mice survived when immunization occurred by the i.m. route. Since Ail has virulence and immunogenic potential, a mutated version of Ail devoid of its virulence properties was created, and the genetically modified ail replaced the native ail gene on the chromosome of the Δlpp ΔmsbB double mutant, creating a Δlpp ΔmsbB::ailL2 vaccine strain. This newly generated mutant was attenuated similarly to the Δlpp ΔmsbB Δail triple mutant when administered by the i.m. route and provided 100% protection to animals against subsequent pneumonic challenge. Not only were the two above-mentioned mutants cleared rapidly from the initial i.m. site of injection in animals with no histopathological lesions, the immunized mice did not exhibit any disease symptoms during immunization or after subsequent exposure to WT CO92. These two mutants triggered balanced Th1- and Th2-based antibody responses and cell-mediated immunity. A substantial increase in interleukin-17 (IL-17) from the T cells of vaccinated mice, a cytokine of the Th17 cells, further augmented their vaccine potential. Thus, the Δlpp ΔmsbB Δail and Δlpp ΔmsbB::ailL2 mutants represent excellent vaccine candidates for plague, with the latter mutant still retaining Ail immunogenicity but

Choline kinase β mutant mice exhibit reduced phosphocholine, elevated osteoclast activity, and low bone mass.

PubMed

Kular, Jasreen; Tickner, Jennifer C; Pavlos, Nathan J; Viola, Helena M; Abel, Tamara; Lim, Bay Sie; Yang, Xiaohong; Chen, Honghui; Cook, Robert; Hool, Livia C; Zheng, Ming Hao; Xu, Jiake

2015-01-16

The maintenance of bone homeostasis requires tight coupling between bone-forming osteoblasts and bone-resorbing osteoclasts. However, the precise molecular mechanism(s) underlying the differentiation and activities of these specialized cells are still largely unknown. Here, we identify choline kinase β (CHKB), a kinase involved in the biosynthesis of phosphatidylcholine, as a novel regulator of bone homeostasis. Choline kinase β mutant mice (flp/flp) exhibit a systemic low bone mass phenotype. Consistently, osteoclast numbers and activity are elevated in flp/flp mice. Interestingly, osteoclasts derived from flp/flp mice exhibit reduced sensitivity to excessive levels of extracellular calcium, which could account for the increased bone resorption. Conversely, supplementation of cytidine 5'-diphosphocholine in vivo and in vitro, a regimen that bypasses CHKB deficiency, restores osteoclast numbers to physiological levels. Finally, we demonstrate that, in addition to modulating osteoclast formation and function, loss of CHKB corresponds with a reduction in bone formation by osteoblasts. Taken together, these data posit CHKB as a new modulator of bone homeostasis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Ontogeny of SERT Expression and Antidepressant-like Response to Escitalopram in Wild-Type and SERT Mutant Mice.

PubMed

Mitchell, Nathan C; Gould, Georgianna G; Koek, Wouter; Daws, Lynette C

2016-08-01

Depression is a disabling affective disorder for which the majority of patients are not effectively treated. This problem is exacerbated in children and adolescents for whom only two antidepressants are approved, both of which are selective serotonin reuptake inhibitor (SSRIs). Unfortunately SSRIs are often less effective in juveniles than in adults; however, the mechanism(s) underlying age-dependent responses to SSRIs is unknown. To this end, we compared the antidepressant-like response to the SSRI escitalopram using the tail suspension test and saturation binding of [(3)H]citalopram to the serotonin transporter (SERT), the primary target of SSRIs, in juvenile [postnatal day (P)21], adolescent (P28), and adult (P90) wild-type (SERT+/+) mice. In addition, to model individuals carrying low-expressing SERT variants, we studied mice with reduced SERT expression (SERT+/-) or lacking SERT (SERT-/-). Maximal antidepressant-like effects were less in P21 mice relative to P90 mice. This was especially apparent in SERT+/- mice. However, the potency for escitalopram to produce antidepressant-like effects in SERT+/+ and SERT+/- mice was greater in P21 and P28 mice than in adults. SERT expression increased with age in terminal regions and decreased with age in cell body regions. Binding affinity values did not change as a function of age or genotype. As expected, in SERT-/- mice escitalopram produced no behavioral effects, and there was no specific [(3)H]citalopram binding. These data reveal age- and genotype-dependent shifts in the dose-response for escitalopram to produce antidepressant-like effects, which vary with SERT expression, and may contribute to the limited therapeutic response to SSRIs in juveniles and adolescents. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Functional verification of a porcine myostatin propeptide mutant.

PubMed

Ma, Dezun; Jiang, Shengwang; Gao, Pengfei; Qian, Lili; Wang, Qingqing; Cai, Chunbo; Xiao, Gaojun; Yang, Jinzeng; Cui, Wentao

2015-10-01

Myostatin is a member of TGF-β superfamily that acts as a key negative regulator in development and growth of embryonic and postnatal muscles. In this study, the inhibitory activities of recombinant porcine myostatin propeptide and its mutated form (at the cleavage site of metalloproteinases of BMP-1/TLD family) against murine myostatin was evaluated in vivo by intraperitoneal injection into mice. Results showed that both wild type and mutated form of porcine propeptide significantly inhibited myostatin activity in vivo. The average body weight of mice receiving wild type propeptide or its mutated form increased by 12.5 % and 24.14%, respectively, compared to mice injected with PBS, implying that the in vivo efficacy of porcine propeptide mutant is greater than its wild type propeptide. Transgenic mice expressing porcine myostatin propeptide mutant were generated to further verify the results obtained from mice injected with recombinant porcine propeptide mutant. Compared with wild type (non-transgenic) mice, relative weight of gastrocnemius, rectusfemoris, and tibialis anterior increased by 22.14 %, 34.13 %, 25.37%, respectively, in transgenic male mice, and by 19.90 %, 42.47 %, 45.61%, respectively, in transgenic female mice. Our data also demonstrated that the mechanism by which muscle growth enhancement is achieved by these propeptides is due to an increase in fiber sizes, not by an increase in number of fiber cells.

Autophagy and UPR in alpha-crystallin mutant knock-in mouse models of hereditary cataracts.

PubMed

Andley, Usha P; Goldman, Joshua W

2016-01-01

Knock-in mice provide useful models of congenital and age-related cataracts caused by α-crystallin mutations. R49C αA-crystallin and R120G αB-crystallin mutations are linked with hereditary cataracts. Knock-in αA-R49C+/- heterozygotes develop cataracts by 1-2months, whereas homozygote mice have cataracts at birth. The R49C mutation drastically reduces lens protein water solubility and causes cell death in knock-in mouse lenses. Mutant crystallin cannot function as a chaperone, which leads to protein aggregation and lens opacity. Protein aggregation disrupts the lens fiber cell structure and normal development and causes cell death in epithelial and fiber cells. We determined what aspects of the wild-type phenotype are age-dependently altered in the mutant lens. Wild-type, heterozygote (αA-R49C+/-), and homozygote (αA-R49C+/+) mouse lenses were assessed pre- and postnatally for lens morphology (electron microscopy, immunohistochemistry), and autophagy or unfolded protein response markers (immunoblotting). Morphology was altered by embryonic day 17 in R49C+/+ lenses; R49C+/- lens morphology was unaffected at this stage. Active autophagy in the lens epithelium of mutant lenses was indicated by the presence of autophagosomes using electron microscopy. Protein p62 levels, which are degraded specifically by autophagy, increased in αA-R49C mutant versus wild-type lenses, suggesting autophagy inhibition in the mutant lenses. The unfolded protein response marker XBP-1 was upregulated in adult lenses of αB-R120G+/+ mice, suggesting its role in lens opacification. Mutated crystallins alter lens morphology, autophagy, and stress responses. Therapeutic modulation of autophagic pathways may improve protein degradation in cataractous lenses and reduce lens opacity. This article is part of a Special Issue entitled Crystallin Biochemistry in Health and Disease. Copyright © 2015 Elsevier B.V. All rights reserved.

A MEK Inhibitor Abrogates Myeloproliferative Disease in Kras Mutant Mice

PubMed Central

Lyubynska, Natalya; Gorman, Matthew F.; Lauchle, Jennifer O.; Hong, Wan Xing; Akutagawa, Jon K.; Shannon, Kevin; Braun, Benjamin S.

2012-01-01

Chronic and juvenile myelomonocytic leukemias (CMML and JMML) are aggressive myeloproliferative neoplasms that are incurable with conventional chemotherapy. Mutations that deregulate Ras signaling play a central pathogenic role in both disorders, and Mx1-Cre, KrasLSL-G12D mice that express the Kras oncogene develop a fatal disease that closely mimics these two leukemias in humans. Activated Ras controls multiple downstream effectors, but the specific pathways that mediate the leukemogenic effects of hyperactive Ras are unknown. We used PD0325901, a highly selective pharmacological inhibitor of mitogen-activated protein kinase kinase (MEK), a downstream component of the Ras signaling network, to address how deregulated Raf/MEK/ERK signaling drives neoplasm formation in Mx1-Cre, KrasLSL-G12D mice. PD0325901 treatment induced a rapid and sustained reduction in leukocyte counts, enhanced erythropoiesis, prolonged mouse survival, and corrected the aberrant proliferation and differentiation of bone marrow progenitor cells. These responses were due to direct effects of PD0325901 on Kras mutant cells rather than to stimulation of normal hematopoietic cell proliferation. Consistent with the in vivo response, inhibition of MEK reversed the cytokine hypersensitivity characteristic of KrasG12D hematopoietic progenitor cells in vitro. Our data demonstrate that deregulated Raf/MEK/ERK signaling is integral to the growth of Kras-mediated myeloproliferative neoplasias, and further suggest that MEK inhibition could be a useful way to ameliorate functional hematologic abnormalities in patients with CMML and JMML. PMID:21451123

Treadmill performance of mice with cerebellar lesions: 1. Purkinje cell degeneration mutant mice.

PubMed

Le Marec, N; Lalonde, R

1998-02-01

The purpose of this study was to evaluate the sensorimotor skills of a spontaneous mouse mutant, Purkinje cell degeneration (PCD), marked by selective cerebellar cortical atrophy on a treadmill activated at 1 of 2 speeds and at 1 of 3 slopes, requiring forward movements to avoid footshocks. There was no difference in latencies before falling from the belt between PCD mutants and controls during acquisition. However, PCD mutants were impaired on the fast treadmill during retention, implicating the cerebellum in the memory of a motor skill. During acquisition of the slow treadmill task at the 2 lowest slopes of inclination, PCD mutants spent more time walking than controls, an indication of a decreased ability of coordinating whole body movements. The same pattern of higher walking time on the slow treadmill in PCD mutants was evident during retention. These results indicate that the cerebellar cortex is involved in the acquisition and the retention of a task requiring equilibrium.

Thymidine Kinase-Negative Herpes Simplex Virus 1 Can Efficiently Establish Persistent Infection in Neural Tissues of Nude Mice.

PubMed

Huang, Chih-Yu; Yao, Hui-Wen; Wang, Li-Chiu; Shen, Fang-Hsiu; Hsu, Sheng-Min; Chen, Shun-Hua

2017-02-15

Herpes simplex virus 1 (HSV-1) establishes latency in neural tissues of immunocompetent mice but persists in both peripheral and neural tissues of lymphocyte-deficient mice. Thymidine kinase (TK) is believed to be essential for HSV-1 to persist in neural tissues of immunocompromised mice, because infectious virus of a mutant with defects in both TK and UL24 is detected only in peripheral tissues, but not in neural tissues, of severe combined immunodeficiency mice (T. Valyi-Nagy, R. M. Gesser, B. Raengsakulrach, S. L. Deshmane, B. P. Randazzo, A. J. Dillner, and N. W. Fraser, Virology 199:484-490, 1994, https://doi.org/10.1006/viro.1994.1150). Here we find infiltration of CD4 and CD8 T cells in peripheral and neural tissues of mice infected with a TK-negative mutant. We therefore investigated the significance of viral TK and host T cells for HSV-1 to persist in neural tissues using three genetically engineered mutants with defects in only TK or in both TK and UL24 and two strains of nude mice. Surprisingly, all three mutants establish persistent infection in up to 100% of brain stems and 93% of trigeminal ganglia of adult nude mice at 28 days postinfection, as measured by the recovery of infectious virus. Thus, in mouse neural tissues, host T cells block persistent HSV-1 infection, and viral TK is dispensable for the virus to establish persistent infection. Furthermore, we found 30- to 200-fold more virus in neural tissues than in the eye and detected glycoprotein C, a true late viral antigen, in brainstem neurons of nude mice persistently infected with the TK-negative mutant, suggesting that adult mouse neurons can support the replication of TK-negative HSV-1. Acyclovir is used to treat herpes simplex virus 1 (HSV-1)-infected immunocompromised patients, but treatment is hindered by the emergence of drug-resistant viruses, mostly those with mutations in viral thymidine kinase (TK), which activates acyclovir. TK mutants are detected in brains of immunocompromised

Thymidine Kinase-Negative Herpes Simplex Virus 1 Can Efficiently Establish Persistent Infection in Neural Tissues of Nude Mice

PubMed Central

Huang, Chih-Yu; Yao, Hui-Wen; Wang, Li-Chiu; Shen, Fang-Hsiu

2016-01-01

ABSTRACT Herpes simplex virus 1 (HSV-1) establishes latency in neural tissues of immunocompetent mice but persists in both peripheral and neural tissues of lymphocyte-deficient mice. Thymidine kinase (TK) is believed to be essential for HSV-1 to persist in neural tissues of immunocompromised mice, because infectious virus of a mutant with defects in both TK and UL24 is detected only in peripheral tissues, but not in neural tissues, of severe combined immunodeficiency mice (T. Valyi-Nagy, R. M. Gesser, B. Raengsakulrach, S. L. Deshmane, B. P. Randazzo, A. J. Dillner, and N. W. Fraser, Virology 199:484–490, 1994, https://doi.org/10.1006/viro.1994.1150). Here we find infiltration of CD4 and CD8 T cells in peripheral and neural tissues of mice infected with a TK-negative mutant. We therefore investigated the significance of viral TK and host T cells for HSV-1 to persist in neural tissues using three genetically engineered mutants with defects in only TK or in both TK and UL24 and two strains of nude mice. Surprisingly, all three mutants establish persistent infection in up to 100% of brain stems and 93% of trigeminal ganglia of adult nude mice at 28 days postinfection, as measured by the recovery of infectious virus. Thus, in mouse neural tissues, host T cells block persistent HSV-1 infection, and viral TK is dispensable for the virus to establish persistent infection. Furthermore, we found 30- to 200-fold more virus in neural tissues than in the eye and detected glycoprotein C, a true late viral antigen, in brainstem neurons of nude mice persistently infected with the TK-negative mutant, suggesting that adult mouse neurons can support the replication of TK-negative HSV-1. IMPORTANCE Acyclovir is used to treat herpes simplex virus 1 (HSV-1)-infected immunocompromised patients, but treatment is hindered by the emergence of drug-resistant viruses, mostly those with mutations in viral thymidine kinase (TK), which activates acyclovir. TK mutants are detected in brains of

SELF ADMINISTRATION OF OXYCODONE BY ADOLESCENT AND ADULT MICE AFFECTS STRIATAL NEUROTRANSMITTER RECEPTOR GENE EXPRESSION

PubMed Central

Mayer-Blackwell, B.; Schlussman, S. D.; Butelman, E. R.; Ho, A.; Ott, J.; Kreek, M. J.; Zhang, Y.

2014-01-01

Illicit use of prescription opioid analgesics (e.g., oxycodone) in adolescence is a pressing public health issue. Our goal was to determine whether oxycodone self administration differentially affects striatal neurotransmitter receptor gene expression in the dorsal striatum of adolescent compared to adult C57BL/6J mice. Groups of adolescent mice (4 weeks old, n= 12) and of adult mice (11 weeks old, n= 11) underwent surgery during which a catheter was implanted into their jugular veins. After recovering from surgery, mice self administered oxycodone (0.25 mg/kg/infusion) 2 h/day for 14 consecutive days or served as yoked saline controls. Mice were sacrificed within 1 h after the last self-administration session and the dorsal striatum was isolated for mRNA analysis. Gene expression was analyzed with real time PCR using a commercially available neurotransmitter receptor PCR array containing 84 genes. We found that adolescent mice self administered less oxycodone than adult mice over the 14 days. Monoamine oxidase A (Maoa) and neuropeptide Y receptor 5 mRNA levels were lower in adolescent mice than in adult mice without oxycodone exposure. Oxycodone self administration increased Maoa mRNA levels compared to controls in both age groups. There was a positive correlation of the amount of oxycodone self administered in the last session or across 14 sessions with Maoa mRNA levels. Gastrin-releasing peptide receptor mRNA showed a significant Drug × Age interaction, with point-wise significance. More genes in the dorsal striatum of adolescents (19) changed in response to oxycodone self administration compared to controls than in adult (4) mice. Overall, this study demonstrates that repeated oxycodone self administration alters neurotransmitter receptors gene expression in the dorsal striatum of adolescent and adult mice. PMID:24220688

Voluntary Wheel Running Does not Affect Lipopolysaccharide-Induced Depressive-Like Behavior in Young Adult and Aged Mice

PubMed Central

Martin, Stephen A.; Dantzer, Robert; Kelley, Keith W.; Woods, Jeffrey A.

2014-01-01

Peripheral stimulation of the innate immune system with lipopolysaccharide (LPS) causes prolonged depressive-like behavior in aged mice that is dependent on indoleamine 2,3 dioxygenase (IDO) activation. Regular moderate intensity exercise training has been shown to exert neuroprotective effects that might reduce depressive-like behavior in aged mice. The purpose of this study was to test the hypothesis that voluntary wheel running would attenuate LPS-induced depressive-like behavior and brain IDO gene expression in 4-month-old and 22-month-old C57BL/6J mice. Mice were housed with a running wheel (Voluntary Wheel Running, VWR) or no wheel (Standard) for 30 days (young adult mice) or 70 days (aged mice), after which they were intraperitoneally injected with LPS (young adult mice: 0.83 mg/kg; aged mice: 0.33 mg/kg). Young adult VWR mice ran on average 6.9 km/day, while aged VWR mice ran on average 3.4 km/day. Both young adult and aged VWR mice increased their forced exercise tolerance compared to their respective Standard control groups. VWR had no effect on LPS-induced anorexia, weight-loss, increased immobility in the tail suspension test, and decreased sucrose preference in either young adult or aged mice. Four (young adult mice) and twenty-four (aged mice) hours after injection of LPS transcripts for TNF-α, IL-1β, IL-6, and IDO were upregulated in the whole brain independently of VWR. These results indicate that prolonged physical exercise has no effect on the neuroinflammatory response to LPS and its behavioral consequences. PMID:24281669

Transplantation of Embryonic Cerebellar Grafts Improves Gait Parameters in Ataxic Lurcher Mice.

PubMed

Babuska, Vaclav; Houdek, Zbynek; Tuma, Jan; Purkartova, Zdenka; Tumova, Jana; Kralickova, Milena; Vozeh, Frantisek; Cendelin, Jan

2015-12-01

Hereditary cerebellar ataxias are severe diseases for which therapy is currently not sufficiently effective. One of the possible therapeutic approaches could be neurotransplantation. Lurcher mutant mice are a natural model of olivocerebellar degeneration representing a tool to investigate its pathogenesis as well as experimental therapies for hereditary cerebellar ataxias. The effect of intracerebellar transplantation of embryonic cerebellar solid tissue or cell suspension on motor performance in adult Lurcher mutant and healthy wild-type mice was studied. Brain-derived neurotrophic factor level was measured in the graft and adult cerebellar tissue. Gait analysis and rotarod, horizontal wire, and wooden beam tests were carried out 2 or 6 months after the transplantation. Higher level of the brain-derived neurotrophic factor was found in the Lurcher cerebellum than in the embryonic and adult wild-type tissue. A mild improvement of gait parameters was found in graft-treated Lurcher mice. The effect was more marked in cell suspension grafts than in solid transplants and after the longer period than after the short one. Lurcher mice treated with cell suspension and examined 6 months later had a longer hind paw stride (4.11 vs. 3.73 mm, P < 0.05) and higher swing speed for both forepaws (52.46 vs. 32.79 cm/s, P < 0.01) and hind paws (63.46 vs. 43.67 cm/s, P < 0.001) than controls. On the other hand, classical motor tests were not capable of detecting clearly the change in the motor performance. No strong long-lasting negative effect of the transplantation was seen in wild-type mice, suggesting that the treatment has no harmful impact on the healthy cerebellum.

Auditory processing and morphological anomalies in medial geniculate nucleus of Cntnap2 mutant mice.

PubMed

Truong, Dongnhu T; Rendall, Amanda R; Castelluccio, Brian C; Eigsti, Inge-Marie; Fitch, R Holly

2015-12-01

Genetic epidemiological studies support a role for CNTNAP2 in developmental language disorders such as autism spectrum disorder, specific language impairment, and dyslexia. Atypical language development and function represent a core symptom of autism spectrum disorder (ASD), with evidence suggesting that aberrant auditory processing-including impaired spectrotemporal processing and enhanced pitch perception-may both contribute to an anomalous language phenotype. Investigation of gene-brain-behavior relationships in social and repetitive ASD symptomatology have benefited from experimentation on the Cntnap2 knockout (KO) mouse. However, auditory-processing behavior and effects on neural structures within the central auditory pathway have not been assessed in this model. Thus, this study examined whether auditory-processing abnormalities were associated with mutation of the Cntnap2 gene in mice. Cntnap2 KO mice were assessed on auditory-processing tasks including silent gap detection, embedded tone detection, and pitch discrimination. Cntnap2 knockout mice showed deficits in silent gap detection but a surprising superiority in pitch-related discrimination as compared with controls. Stereological analysis revealed a reduction in the number and density of neurons, as well as a shift in neuronal size distribution toward smaller neurons, in the medial geniculate nucleus of mutant mice. These findings are consistent with a central role for CNTNAP2 in the ontogeny and function of neural systems subserving auditory processing and suggest that developmental disruption of these neural systems could contribute to the atypical language phenotype seen in autism spectrum disorder. (c) 2015 APA, all rights reserved).

Impaired Object Recognition but Normal Social Behavior and Ultrasonic Communication in Cofilin1 Mutant Mice

PubMed Central

Sungur, A. Özge; Stemmler, Lea; Wöhr, Markus; Rust, Marco B.

2018-01-01

Autism spectrum disorder (ASD), schizophrenia (SCZ) and intellectual disability (ID) show a remarkable overlap in symptoms, including impairments in cognition, social behavior and communication. Human genetic studies revealed an enrichment of mutations in actin-related genes for these disorders, and some of the strongest candidate genes control actin dynamics. These findings led to the hypotheses: (i) that ASD, SCZ and ID share common disease mechanisms; and (ii) that, at least in a subgroup of affected individuals, defects in the actin cytoskeleton cause or contribute to their pathologies. Cofilin1 emerged as a key regulator of actin dynamics and we previously demonstrated its critical role for synaptic plasticity and associative learning. Notably, recent studies revealed an over-activation of cofilin1 in mutant mice displaying ASD- or SCZ-like behavioral phenotypes, suggesting that dysregulated cofilin1-dependent actin dynamics contribute to their behavioral abnormalities, such as deficits in social behavior. These findings let us hypothesize: (i) that, apart from cognitive impairments, cofilin1 mutants display additional behavioral deficits with relevance to ASD or SCZ; and (ii) that our cofilin1 mutants represent a valuable tool to study the underlying disease mechanisms. To test our hypotheses, we compared social behavior and ultrasonic communication of juvenile mutants to control littermates, and we did not obtain evidence for impaired direct reciprocal social interaction, social approach or social memory. Moreover, concomitant emission of ultrasonic vocalizations was not affected and time-locked to social activity, supporting the notion that ultrasonic vocalizations serve a pro-social communicative function as social contact calls maintaining social proximity. Finally, cofilin1 mutants did not display abnormal repetitive behaviors. Instead, they performed weaker in novel object recognition, thereby demonstrating that cofilin1 is relevant not only for

Mutant laboratory mice with abnormalities in hair follicle morphogenesis, cycling, and/or structure: an update.

PubMed

Nakamura, Motonobu; Schneider, Marlon R; Schmidt-Ullrich, Ruth; Paus, Ralf

2013-01-01

Human hair disorders comprise a number of different types of alopecia, atrichia, hypotrichosis, distinct hair shaft disorders as well as hirsutism and hypertrichosis. Their causes vary from genodermatoses (e.g. hypotrichoses) via immunological disorders (e.g. alopecia areata, autoimmune cicatrical alopecias) to hormone-dependent abnormalities (e.g. androgenetic alopecia). A large number of spontaneous mouse mutants and genetically engineered mice develop abnormalities in hair follicle morphogenesis, cycling, and/or hair shaft formation, whose analysis has proven invaluable to define the molecular regulation of hair growth, ranging from hair follicle development, and cycling to hair shaft formation and stem cell biology. Also, the accumulating reports on hair phenotypes of mouse strains provide important pointers to better understand the molecular mechanisms underlying human hair growth disorders. Since numerous new mouse mutants with a hair phenotype have been reported since the publication of our earlier review on this matter a decade ago, we present here an updated, tabulated mini-review. The updated annotated tables list a wide selection of mouse mutants with hair growth abnormalities, classified into four categories: Mutations that affect hair follicle (1) morphogenesis, (2) cycling, (3) structure, and (4) mutations that induce extrafollicular events (for example immune system defects) resulting in secondary hair growth abnormalities. This synthesis is intended to provide a useful source of reference when studying the molecular controls of hair follicle growth and differentiation, and whenever the hair phenotypes of a newly generated mouse mutant need to be compared with existing ones. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Mutant ataxin1 disrupts cerebellar development in spinocerebellar ataxia type 1.

PubMed

Edamakanti, Chandrakanth Reddy; Do, Jeehaeh; Didonna, Alessandro; Martina, Marco; Opal, Puneet

2018-06-01

Spinocerebellar ataxia type 1 (SCA1) is an adult-onset neurodegenerative disease caused by a polyglutamine expansion in the protein ATXN1, which is involved in transcriptional regulation. Although symptoms appear relatively late in life, primarily from cerebellar dysfunction, pathogenesis begins early, with transcriptional changes detectable as early as a week after birth in SCA1-knockin mice. Given the importance of this postnatal period for cerebellar development, we asked whether this region might be developmentally altered by mutant ATXN1. We found that expanded ATXN1 stimulates the proliferation of postnatal cerebellar stem cells in SCA1 mice. These hyperproliferating stem cells tended to differentiate into GABAergic inhibitory interneurons rather than astrocytes; this significantly increased the GABAergic inhibitory interneuron synaptic connections, disrupting cerebellar Purkinje cell function in a non-cell autonomous manner. We confirmed the increased basket cell-Purkinje cell connectivity in human SCA1 patients. Mutant ATXN1 thus alters the neural circuitry of the developing cerebellum, setting the stage for the later vulnerability of Purkinje cells to SCA1. We propose that other late-onset degenerative diseases may also be rooted in subtle developmental derailments.

Impaired antibody response against T-dependent antigens in rhino mice.

PubMed

Takaoki, M; Kawaji, H

1980-05-01

The antibody response in rhino mice, which carry a mutant gene hrrh, to thymus-dependent (TD) or thymus-independent (TI) antigens was compared with that of phenotypically normal littermates. The magnitude of antibody response to TD antigens in rhino mice decreased as they grew up, whereas the antibody response to TI antigens in rhino mice was indistinguishable from that of littermates. A transfer of thymus cells from littermates to rhino mice resulted in the partial restoration of the responsiveness to TD antigens. The experiments employing adoptive transfer of spleen cells from rhino mice to the irradiated normal mice suggested that the hyporesponsiveness of TD antigens of adult rhino mice was mainly due to the defect in the T helper cell activities rather than either the increase of the suppressor cells or defects in other cell types.

APP heterozygosity averts memory deficit in knockin mice expressing the Danish dementia BRI2 mutant.

PubMed

Tamayev, Robert; Matsuda, Shuji; Giliberto, Luca; Arancio, Ottavio; D'Adamio, Luciano

2011-05-17

An autosomal dominant mutation in the BRI2/ITM2B gene causes familial Danish dementia (FDD). Analysis of FDD(KI) mice, a mouse model of FDD genetically congruous to the human disease since they carry one mutant and one wild-type Bri2/Itm2b allele, has shown that the Danish mutation causes loss of Bri2 protein, synaptic plasticity and memory impairments. BRI2 is a physiological interactor of Aβ-precursor protein (APP), a gene associated with Alzheimer disease, which inhibits processing of APP. Here, we show that APP/Bri2 complexes are reduced in synaptic membranes of FDD(KI) mice. Consequently, APP metabolites derived from processing of APP by β-, α- and γ-secretases are increased in Danish dementia mice. APP haplodeficiency prevents memory and synaptic dysfunctions, consistent with a role for APP metabolites in the pathogenesis of memory and synaptic deficits. This genetic suppression provides compelling evidence that APP and BRI2 functionally interact, and that the neurological effects of the Danish form of BRI2 only occur when sufficient levels of APP are supplied by two alleles. This evidence establishes a pathogenic sameness between familial Danish and Alzheimer's dementias.

APP heterozygosity averts memory deficit in knockin mice expressing the Danish dementia BRI2 mutant

PubMed Central

Tamayev, Robert; Matsuda, Shuji; Giliberto, Luca; Arancio, Ottavio; D'Adamio, Luciano

2011-01-01

An autosomal dominant mutation in the BRI2/ITM2B gene causes familial Danish dementia (FDD). Analysis of FDDKI mice, a mouse model of FDD genetically congruous to the human disease since they carry one mutant and one wild-type Bri2/Itm2b allele, has shown that the Danish mutation causes loss of Bri2 protein, synaptic plasticity and memory impairments. BRI2 is a physiological interactor of Aβ-precursor protein (APP), a gene associated with Alzheimer disease, which inhibits processing of APP. Here, we show that APP/Bri2 complexes are reduced in synaptic membranes of FDDKI mice. Consequently, APP metabolites derived from processing of APP by β-, α- and γ-secretases are increased in Danish dementia mice. APP haplodeficiency prevents memory and synaptic dysfunctions, consistent with a role for APP metabolites in the pathogenesis of memory and synaptic deficits. This genetic suppression provides compelling evidence that APP and BRI2 functionally interact, and that the neurological effects of the Danish form of BRI2 only occur when sufficient levels of APP are supplied by two alleles. This evidence establishes a pathogenic sameness between familial Danish and Alzheimer's dementias. PMID:21587206

Multiple Renal Cyst Development but Not Situs Abnormalities in Transgenic RNAi Mice against Inv::GFP Rescue Gene

PubMed Central

Kamijho, Yuki; Shiozaki, Yayoi; Sakurai, Eiki; Hanaoka, Kazunori; Watanabe, Daisuke

2014-01-01

In this study we generated RNA interference (RNAi)-mediated gene knockdown transgenic mice (transgenic RNAi mice) against the functional Inv gene. Inv mutant mice show consistently reversed internal organs (situs inversus), multiple renal cysts and neonatal lethality. The Inv::GFP-rescue mice, which introduced the Inv::GFP fusion gene, can rescue inv mutant mice phenotypes. This indicates that the Inv::GFP gene is functional in vivo. To analyze the physiological functions of the Inv gene, and to demonstrate the availability of transgenic RNAi mice, we introduced a short hairpin RNA expression vector against GFP mRNA into Inv::GFP-rescue mice and analyzed the gene silencing effects and Inv functions by examining phenotypes. Transgenic RNAi mice with the Inv::GFP-rescue gene (Inv-KD mice) down-regulated Inv::GFP fusion protein and showed hypomorphic phenotypes of inv mutant mice, such as renal cyst development, but not situs abnormalities or postnatal lethality. This indicates that shRNAi-mediated gene silencing systems that target the tag sequence of the fusion gene work properly in vivo, and suggests that a relatively high level of Inv protein is required for kidney development in contrast to left/right axis determination. Inv::GFP protein was significantly down-regulated in the germ cells of Inv-KD mice testis compared with somatic cells, suggesting the existence of a testicular germ cell-specific enhanced RNAi system that regulates germ cell development. The Inv-KD mouse is useful for studying Inv gene functions in adult tissue that are unable to be analyzed in inv mutant mice showing postnatal lethality. In addition, the shRNA-based gene silencing system against the tag sequence of the fusion gene can be utilized as a new technique to regulate gene expression in either in vitro or in vivo experiments. PMID:24586938

Responses of flocculus and vestibular nuclei neurons in Weaver mutant mice (B6CBA wv/wv) to combined head and body rotation.

PubMed

Grüsser-Cornehls, U

1995-01-01

The responses of vestibular nuclei (Vn) neurons and floccular Purkinje (P) cells to natural stimulation of the horizontal canals were recorded in paralyzed Weaver mutant mice. The Weaver mice suffer from an almost complete postnatal degeneration of granule cells and a portion of the P cells (Sidman et al. 1965). Parallel fibers are never elaborated (Bradley and Berry 1978). Recording sites were localized by means of small, iontophoretically applied HRP markings. Phase and sensitivity were analyzed by a Fourier analysis and a "best sine fitting" program. As in the normal "control" mice (Grüsser-Cornehls et al. 1995), the "simple spike" discharges of Vn and P cells in Weaver mutant mice are modulated sinusoidally upon sinusoidal stimulation. The neuronal response amplitude at fundamental frequency (determined from peristimulus time histograms, PSTHs increased with frequency (0.05-0.5 Hz) for both Vn and floccular neurons. The stimulus frequency/response amplitude and sensitivity (re velocity) curves for floccular neurons are distinctly lower in magnitude than those of Vn neurons (P < 0.01). In our sample of neurons, the Vn neurons curves of the mutants display a remarkable be behavior: the mean value curve of type I neurons is shifted upward, indicating a loss of inhibition but that of type II, downward, demonstrating a downregulation in comparison with the control values. The difference between the two curves is statistically significant (P < 0.001). The mean value curve of all mutant Vn neurons depends on the different fractions of type I and type II neurons in the sample investigated. In our investigations, the mean value curves of both type I and type II neurons also exceed those of the normal controls. The phase shift relative to head angular velocity in the midfrequency range in Vn neurons was very similar to that in normal controls, but the phase advance in the range of 0.3-0.5 Hz was somewhat larger and the SD larger over the whole range tested. Concerning

Fragile X-like behaviors and abnormal cortical dendritic spines in cytoplasmic FMR1-interacting protein 2-mutant mice.

PubMed

Han, Kihoon; Chen, Hogmei; Gennarino, Vincenzo A; Richman, Ronald; Lu, Hui-Chen; Zoghbi, Huda Y

2015-04-01

Silencing of fragile X mental retardation 1 (FMR1) gene and loss of fragile X mental retardation protein (FMRP) cause fragile X syndrome (FXS), a genetic disorder characterized by intellectual disability and autistic behaviors. FMRP is an mRNA-binding protein regulating neuronal translation of target mRNAs. Abnormalities in actin-rich dendritic spines are major neuronal features in FXS, but the molecular mechanism and identity of FMRP targets mediating this phenotype remain largely unknown. Cytoplasmic FMR1-interacting protein 2 (Cyfip2) was identified as an interactor of FMRP, and its mRNA is a highly ranked FMRP target in mouse brain. Importantly, Cyfip2 is a component of WAVE regulatory complex, a key regulator of actin cytoskeleton, suggesting that Cyfip2 could be implicated in the dendritic spine phenotype of FXS. Here, we generated and characterized Cyfip2-mutant (Cyfip2(+/-)) mice. We found that Cyfip2(+/-) mice exhibited behavioral phenotypes similar to Fmr1-null (Fmr1(-/y)) mice, an animal model of FXS. Synaptic plasticity and dendritic spines were normal in Cyfip2(+/-) hippocampus. However, dendritic spines were altered in Cyfip2(+/-) cortex, and the dendritic spine phenotype of Fmr1(-/y) cortex was aggravated in Fmr1(-/y); Cyfip2(+/-) double-mutant mice. In addition to the spine changes at basal state, metabotropic glutamate receptor (mGluR)-induced dendritic spine regulation was impaired in both Fmr1(-/y) and Cyfip2(+/-) cortical neurons. Mechanistically, mGluR activation induced mRNA translation-dependent increase of Cyfip2 in wild-type cortical neurons, but not in Fmr1(-/y) or Cyfip2(+/-) neurons. These results suggest that misregulation of Cyfip2 function and its mGluR-induced expression contribute to the neurobehavioral phenotypes of FXS. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A single day of 5-azacytidine exposure during development induces neurodegeneration in neonatal mice and neurobehavioral deficits in adult mice.

PubMed

Subbanna, Shivakumar; Nagre, Nagaraja N; Shivakumar, Madhu; Basavarajappa, Balapal S

2016-12-01

The present study was undertaken to evaluate the immediate and long-term effects of a single-day exposure to 5-Azacytidine (5-AzaC), a DNA methyltransferase inhibitor, on neurobehavioral abnormalities in mice. Our findings suggest that the 5-AzaC treatment significantly inhibited DNA methylation, impaired extracellular signal-regulated kinase (ERK1/2) activation and reduced expression of the activity-regulated cytoskeleton-associated protein (Arc). These events lead to the activation of caspase-3 (a marker for neurodegeneration) in several brain regions, including the hippocampus and cortex, two brain areas that are essential for memory formation and memory storage, respectively. 5-AzaC treatment of P7 mice induced significant deficits in spatial memory, social recognition, and object memory in adult mice and deficits in long-term potentiation (LTP) in adult hippocampal slices. Together, these data demonstrate that the inhibition of DNA methylation by 5-AzaC treatment in P7 mice causes neurodegeneration and impairs ERK1/2 activation and Arc protein expression in neonatal mice and induces behavioral abnormalities in adult mice. DNA methylation-mediated mechanisms appear to be necessary for the proper maturation of synaptic circuits during development, and disruption of this process by 5-AzaC could lead to abnormal cognitive function. Published by Elsevier Inc.

Transgenic mice overexpressing tyrosine-to-cysteine mutant human alpha-synuclein: a progressive neurodegenerative model of diffuse Lewy body disease.

PubMed

Zhou, Wenbo; Milder, Julie B; Freed, Curt R

2008-04-11

Abnormal aggregation of human alpha-synuclein in Lewy bodies and Lewy neurites is a pathological hallmark of Parkinson disease and dementia with Lewy bodies. Studies have shown that oxidation and nitration of alpha-synuclein lead to the formation of stable dimers and oligomers through dityrosine cross-linking. Previously we have reported that tyrosine-to-cysteine mutations, particularly at the tyrosine 39 residue (Y39C), significantly enhanced alpha-synuclein fibril formation and neurotoxicity. In the current study, we have generated transgenic mice expressing the Y39C mutant human alpha-synuclein gene controlled by the mouse Thy1 promoter. Mutant human alpha-synuclein was widely expressed in transgenic mouse brain, resulting in 150% overexpression relative to endogenous mouse alpha-synuclein. At age 9-12 months, transgenic mice began to display motor dysfunction in rotarod testing. Older animals aged 15-18 months showed progressive accumulation of human alpha-synuclein oligomers, associated with worse motor function and cognitive impairment in the Morris water maze. By age 21-24 months, alpha-synuclein aggregates were further increased, accompanied by severe behavioral deficits. At this age, transgenic mice developed neuropathology, such as Lewy body-like alpha-synuclein and ubiquitin-positive inclusions, phosphorylation at Ser(129) of human alpha-synuclein, and increased apoptotic cell death. In summary, Y39C human alpha-synuclein transgenic mice show age-dependent, progressive neuronal degeneration with motor and cognitive deficits similar to diffuse Lewy body disease. The time course of alpha-synuclein oligomer accumulation coincided with behavioral and pathological changes, indicating that these oligomers may initiate protein aggregation, disrupt cellular function, and eventually lead to neuronal death.

Transforming Growth Factor Beta (TGFβ1, TGFβ2 and TGFβ3) Null-Mutant Phenotypes in Embryonic Gonadal Development

PubMed Central

Memon, Mushtaq A.; Anway, Matthew D.; Covert, Trevor R.; Uzumcu, Mehmet; Skinner, Michael K.

2008-01-01

The role transforming growth factor beta (TGFb) isoforms TGFb1, TGFb2 and TGFb3 have in the regulation of embryonic gonadal development was investigated with the use of null-mutant (i.e. knockout) mice for each of the TGFb isoforms. Late embryonic gonadal development was investigated because homozygote TGFb null-mutant mice generally die around birth, with some embryonic loss as well. In the testis, the TGFb1 null-mutant mice had a decrease in the number of germ cells at birth, postnatal day 0 (P0). In the testis, the TGFb2 null-mutant mice had a decrease in the number of seminiferous cords at embryonic day 15 (E15). In the ovary, the TGFb2 null-mutant mice had an increase in the number of germ cells at P0. TGFb isoforms appear to have a role in gonadal development, but interactions between the isoforms is speculated to compensate in the different TGFb isoform null-mutant mice. PMID:18790002

Autistic-like social behaviour in Shank2-mutant mice improved by restoring NMDA receptor function.

PubMed

Won, Hyejung; Lee, Hye-Ryeon; Gee, Heon Yung; Mah, Won; Kim, Jae-Ick; Lee, Jiseok; Ha, Seungmin; Chung, Changuk; Jung, Eun Suk; Cho, Yi Sul; Park, Sae-Geun; Lee, Jung-Soo; Lee, Kyungmin; Kim, Daesoo; Bae, Yong Chul; Kaang, Bong-Kiun; Lee, Min Goo; Kim, Eunjoon

2012-06-13

Autism spectrum disorder (ASD) is a group of conditions characterized by impaired social interaction and communication, and restricted and repetitive behaviours. ASD is a highly heritable disorder involving various genetic determinants. Shank2 (also known as ProSAP1) is a multi-domain scaffolding protein and signalling adaptor enriched at excitatory neuronal synapses, and mutations in the human SHANK2 gene have recently been associated with ASD and intellectual disability. Although ASD-associated genes are being increasingly identified and studied using various approaches, including mouse genetics, further efforts are required to delineate important causal mechanisms with the potential for therapeutic application. Here we show that Shank2-mutant (Shank2(-/-)) mice carrying a mutation identical to the ASD-associated microdeletion in the human SHANK2 gene exhibit ASD-like behaviours including reduced social interaction, reduced social communication by ultrasonic vocalizations, and repetitive jumping. These mice show a marked decrease in NMDA (N-methyl-D-aspartate) glutamate receptor (NMDAR) function. Direct stimulation of NMDARs with D-cycloserine, a partial agonist of NMDARs, normalizes NMDAR function and improves social interaction in Shank2(-/-) mice. Furthermore, treatment of Shank2(-/-) mice with a positive allosteric modulator of metabotropic glutamate receptor 5 (mGluR5), which enhances NMDAR function via mGluR5 activation, also normalizes NMDAR function and markedly enhances social interaction. These results suggest that reduced NMDAR function may contribute to the development of ASD-like phenotypes in Shank2(-/-) mice, and mGluR modulation of NMDARs offers a potential strategy to treat ASD.

Insights into wild-type and mutant p53 functions provided by genetically engineered mice.

PubMed

Donehower, Lawrence A

2014-06-01

Recent whole-exome sequencing studies of numerous human cancers have now conclusively shown that the TP53 tumor-suppressor gene is the most frequently mutated gene in human cancers. Despite extensive studies of the TP53 gene and its encoded protein (p53), our understanding of how TP53 mutations contribute to cancer initiation and progression remain incomplete. Genetically engineered mice with germline or inducible Trp53 somatic mutations have provided important insights into the mechanisms by which different types of p53 mutation influence cancer development. Trp53 germline mutations that alter specific p53 structural domains or posttranslation modification sites have benefitted our understanding of wild-type p53 functions in a whole organism context. Moreover, genetic approaches to reestablish functional wild-type p53 to p53-deficient tissues and tumors have increased our understanding of the therapeutic potential of restoring functional p53 signaling to cancers. This review outlines many of the key insights provided by the various categories of Trp53 mutant mice that have been generated by multiple genetic engineering approaches. © 2014 WILEY PERIODICALS, INC.

Retarded axonal transport of R406W mutant tau in transgenic mice with a neurodegenerative tauopathy.

PubMed

Zhang, Bin; Higuchi, Makoto; Yoshiyama, Yasumasa; Ishihara, Takeshi; Forman, Mark S; Martinez, Dan; Joyce, Sonali; Trojanowski, John Q; Lee, Virginia M-Y

2004-05-12

Intracellular accumulations of filamentous tau inclusions are neuropathological hallmarks of neurodegenerative diseases known as tauopathies. The discovery of multiple pathogenic tau gene mutations in many kindreds with familial frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) unequivocally confirmed the central role of tau abnormalities in the etiology of neurodegenerative disorders. To examine the effects of tau gene mutations and the role of tau abnormalities in neurodegenerative tauopathies, transgenic (Tg) mice were engineered to express the longest human tau isoform (T40) with or without the R406W mutation (RW and hWT Tg mice, respectively) that is pathogenic for FTDP-17 in several kindreds. RW but not hWT tau Tg mice developed an age-dependent accumulation of insoluble filamentous tau aggregates in neuronal perikarya of the cerebral cortex, hippocampus, cerebellum, and spinal cord. Significantly, CNS axons in RW mice contained reduced levels of tau when compared with hWT mice, and this was linked to retarded axonal transport and increased accumulation of an insoluble pool of RW but not hWT tau. Furthermore, RW but not hWT mice demonstrated neurodegeneration and a reduced lifespan. These data indicate that the R406W mutation causes reduced binding of this mutant tau to microtubules, resulting in slower axonal transport. This altered tau function caused by the RW mutation leads to increased accumulation and reduced solubility of RW tau in an age-dependent manner, culminating in the formation of filamentous intraneuronal tau aggregates similar to that observed in tauopathy patients.

The thymus of the hairless rhino-j (hr/hr-j) mice

PubMed Central

SAN JOSE, I.; GARCÍA-SUÁREZ, O.; HANNESTAD, J.; CABO, R.; GAUNA, L.; REPRESA, J.; VEGA, J. A.

2001-01-01

The hairless (hr) gene is expressed in a large number of tissues, primarily the skin, and a mutation in the hr gene is responsible for the typical cutaneous phenotype of hairless mice. Mutant hr mouse strains show immune defects involving especially T cells and macrophages, as well as an age-related immunodeficiency and an accelerated atrophy of the thymus. These data suggest that the hr mutation causes a defect of this organ, although hr transcripts have not been detected in fetal or adult mice thymus. The present study analyses the thymus of young (3 mo) and adult (9 mo) homozygous hr-rh-j mice (a strain of hairless mice) by means of structural techniques and immunohistochemistry to selectively identify thymic epithelial cells, dendritic cells, and macrophages. There were structural alterations in the thymus of both young and adult rh-rh-j mice, which were more severe in older animals. These alterations consisted of relative cortical atrophy, enlargement of blood vessels, proliferation of perivascular connective tissue, and the appearance of cysts. hr-rh-j mice also showed a decrease in the number of epithelial and dendritic cells, and macrophages. Taken together, present results strongly suggest degeneration and accelerated age-dependent regression of the thymus in hr-rh-j mice, which could explain at least in part the immune defects reported in hairless mouse strains. PMID:11327202

Probucol ameliorates renal and metabolic sequelae of primary CoQ deficiency in Pdss2 mutant mice.

PubMed

Falk, Marni J; Polyak, Erzsebet; Zhang, Zhe; Peng, Min; King, Rhonda; Maltzman, Jonathan S; Okwuego, Ezinne; Horyn, Oksana; Nakamaru-Ogiso, Eiko; Ostrovsky, Julian; Xie, Letian X; Chen, Jia Yan; Marbois, Beth; Nissim, Itzhak; Clarke, Catherine F; Gasser, David L

2011-07-01

Therapy of mitochondrial respiratory chain diseases is complicated by limited understanding of cellular mechanisms that cause the widely variable clinical findings. Here, we show that focal segmental glomerulopathy-like kidney disease in Pdss2 mutant animals with primary coenzyme Q (CoQ) deficiency is significantly ameliorated by oral treatment with probucol (1% w/w). Preventative effects in missense mutant mice are similar whether fed probucol from weaning or for 3 weeks prior to typical nephritis onset. Furthermore, treating symptomatic animals for 2 weeks with probucol significantly reduces albuminuria. Probucol has a more pronounced health benefit than high-dose CoQ(10) supplementation and uniquely restores CoQ(9) content in mutant kidney. Probucol substantially mitigates transcriptional alterations across many intermediary metabolic domains, including peroxisome proliferator-activated receptor (PPAR) pathway signaling. Probucol's beneficial effects on the renal and metabolic manifestations of Pdss2 disease occur despite modest induction of oxidant stress and appear independent of its hypolipidemic effects. Rather, decreased CoQ(9) content and altered PPAR pathway signaling appear, respectively, to orchestrate the glomerular and global metabolic consequences of primary CoQ deficiency, which are both preventable and treatable with oral probucol therapy. Copyright © 2011 EMBO Molecular Medicine.

Gain-of-function mutant of angiotensin II receptor, type 1A, causes hypertension and cardiovascular fibrosis in mice

PubMed Central

Billet, Sandrine; Bardin, Sabine; Verp, Sonia; Baudrie, Véronique; Michaud, Annie; Conchon, Sophie; Muffat-Joly, Martine; Escoubet, Brigitte; Souil, Evelyne; Hamard, Ghislaine; Bernstein, Kenneth E.; Gasc, Jean Marie; Elghozi, Jean-Luc; Corvol, Pierre; Clauser, Eric

2007-01-01

The role of the renin-angiotensin system has been investigated by overexpression or inactivation of its different genes in animals. However, there is no data concerning the effect of the constitutive activation of any component of the system. A knockin mouse model has been constructed with a gain-of-function mutant of the Ang II receptor, type 1A (AT1A), associating a constitutively activating mutation (N111S) with a C-terminal deletion, which impairs receptor internalization and desensitization. In vivo consequences of this mutant receptor expression in homozygous mice recapitulate its in vitro characteristics: the pressor response is more sensitive to Ang II and longer lasting. These mice present with a moderate (~20 mmHg) and stable increase in BP. They also develop early and progressive renal fibrosis and cardiac fibrosis and diastolic dysfunction. However, there was no overt cardiac hypertrophy. The hormonal parameters (low-renin and inappropriately normal aldosterone productions) mimic those of low-renin human hypertension. This new model reveals that a constitutive activation of AT1A leads to cardiac and renal fibrosis in spite of a modest effect on BP and will be useful for investigating the role of Ang II in target organs in a model similar to some forms of human hypertension. PMID:17607364

Functional Motor Recovery from Motoneuron Axotomy Is Compromised in Mice with Defective Corticospinal Projections

PubMed Central

Ding, Yuetong; Qu, Yibo; Feng, Jia; Wang, Meizhi; Han, Qi; So, Kwok-Fai; Wu, Wutian; Zhou, Libing

2014-01-01

Brachial plexus injury (BPI) and experimental spinal root avulsion result in loss of motor function in the affected segments. After root avulsion, significant motoneuron function is restored by re-implantation of the avulsed root. How much this functional recovery depends on corticospinal inputs is not known. Here, we studied that question using Celsr3|Emx1 mice, in which the corticospinal tract (CST) is genetically absent. In adult mice, we tore off right C5–C7 motor and sensory roots and re-implanted the right C6 roots. Behavioral studies showed impaired recovery of elbow flexion in Celsr3|Emx1 mice compared to controls. Five months after surgery, a reduced number of small axons, and higher G-ratio of inner to outer diameter of myelin sheaths were observed in mutant versus control mice. At early stages post-surgery, mutant mice displayed lower expression of GAP-43 in spinal cord and of myelin basic protein (MBP) in peripheral nerves than control animals. After five months, mutant animals had atrophy of the right biceps brachii, with less newly formed neuromuscular junctions (NMJs) and reduced peak-to-peak amplitudes in electromyogram (EMG), than controls. However, quite unexpectedly, a higher motoneuron survival rate was found in mutant than in control mice. Thus, following root avulsion/re-implantation, the absence of the CST is probably an important reason to hamper axonal regeneration and remyelination, as well as target re-innervation and formation of new NMJ, resulting in lower functional recovery, while fostering motoneuron survival. These results indicate that manipulation of corticospinal transmission may help improve functional recovery following BPI. PMID:25003601

Premature aging of the hippocampal neurogenic niche in adult Bmal1-deficient mice.

PubMed

Ali, Amira A H; Schwarz-Herzke, Beryl; Stahr, Anna; Prozorovski, Timour; Aktas, Orhan; von Gall, Charlotte

2015-06-01

Hippocampal neurogenesis undergoes dramatic age-related changes. Mice with targeted deletion of the clock geneBmal1 (Bmal1(-/-)) show disrupted regulation of reactive oxygen species homeostasis, accelerated aging, neurodegeneration and cognitive deficits. As proliferation of neuronal progenitor/precursor cells (NPCs) is enhanced in young Bmal1(-/-) mice, we tested the hypothesis that this results in premature aging of hippocampal neurogenic niche in adult Bmal1(-/-) mice as compared to wildtype littermates. We found significantly reduced pool of hippocampal NPCs, scattered distribution, enhanced survival of NPCs and an increased differentiation of NPCs into the astroglial lineage at the expense of the neuronal lineage. Immunoreaction of the redox sensitive histone deacetylase Sirtuine 1, peroxisomal membrane protein at 70 kDa and expression of the cell cycle inhibitor p21(Waf1/CIP1) were increased in adult Bmal1(-/-) mice. In conclusion, genetic disruption of the molecular clockwork leads to accelerated age-dependent decline in adult neurogenesis presumably as a consequence of oxidative stress.

Age-Dependent Ocular Dominance Plasticity in Adult Mice

PubMed Central

Lehmann, Konrad; Löwel, Siegrid

2008-01-01

Background Short monocular deprivation (4 days) induces a shift in the ocular dominance of binocular neurons in the juvenile mouse visual cortex but is ineffective in adults. Recently, it has been shown that an ocular dominance shift can still be elicited in young adults (around 90 days of age) by longer periods of deprivation (7 days). Whether the same is true also for fully mature animals is not yet known. Methodology/Principal Findings We therefore studied the effects of different periods of monocular deprivation (4, 7, 14 days) on ocular dominance in C57Bl/6 mice of different ages (25 days, 90–100 days, 109–158 days, 208–230 days) using optical imaging of intrinsic signals. In addition, we used a virtual optomotor system to monitor visual acuity of the open eye in the same animals during deprivation. We observed that ocular dominance plasticity after 7 days of monocular deprivation was pronounced in young adult mice (90–100 days) but significantly weaker already in the next age group (109–158 days). In animals older than 208 days, ocular dominance plasticity was absent even after 14 days of monocular deprivation. Visual acuity of the open eye increased in all age groups, but this interocular plasticity also declined with age, although to a much lesser degree than the optically detected ocular dominance shift. Conclusions/Significance These data indicate that there is an age-dependence of both ocular dominance plasticity and the enhancement of vision after monocular deprivation in mice: ocular dominance plasticity in binocular visual cortex is most pronounced in young animals, reduced but present in adolescence and absent in fully mature animals older than 110 days of age. Mice are thus not basically different in ocular dominance plasticity from cats and monkeys which is an absolutely essential prerequisite for their use as valid model systems of human visual disorders. PMID:18769674

Reanalysis of parabiosis of obesity mutants in the age of leptin.

PubMed

Zeng, Wenwen; Lu, Yi-Hsueh; Lee, Jonah; Friedman, Jeffrey M

2015-07-21

In this study we set out to explain the differing effects of parabiosis with genetically diabetic (db) mice versus administration of recombinant leptin. Parabiosis of db mutant, which overexpress leptin, to wildtype (WT) or genetically obese (ob) mice has been reported to cause death by starvation, whereas leptin infusions do not produce lethality at any dose or mode of delivery tested. Leptin is not posttranslationally modified other than a single disulphide bond, raising the possibility that it might require additional factor(s) to exert the maximal appetite-suppressing effect. We reconfirmed the lethal effect of parabiosis of db mutant on WT mice and further showed that this lethality could not be rescued by administration of ghrelin or growth hormone. We then initiated a biochemical fractionation of a high-molecular-weight leptin complex from human plasma and identified clusterin as a major component of this leptin-containing complex. However, in contrast to previous reports, we failed to observe a leptin-potentiating effect of either exogenous or endogenous clusterin, and parabiosis of db clusterin(-/-) double-mutant to WT mice still caused lethality. Intriguingly, in parabiotic pairs of two WT mice, leptin infusion into one of the mice led to an enhanced starvation response during calorie restriction as evidenced by increased plasma ghrelin and growth-hormone levels. Moreover, leptin treatment resulted in death of the parabiotic pairs. These data suggest that the appetite suppression in WT mice after parabiosis to db mutants is the result of induced hyperleptinemia combined with the stress or other aspect(s) of the parabiosis procedure.

Reanalysis of parabiosis of obesity mutants in the age of leptin

PubMed Central

Zeng, Wenwen; Lu, Yi-Hsueh; Lee, Jonah; Friedman, Jeffrey M.

2015-01-01

In this study we set out to explain the differing effects of parabiosis with genetically diabetic (db) mice versus administration of recombinant leptin. Parabiosis of db mutant, which overexpress leptin, to wildtype (WT) or genetically obese (ob) mice has been reported to cause death by starvation, whereas leptin infusions do not produce lethality at any dose or mode of delivery tested. Leptin is not posttranslationally modified other than a single disulphide bond, raising the possibility that it might require additional factor(s) to exert the maximal appetite-suppressing effect. We reconfirmed the lethal effect of parabiosis of db mutant on WT mice and further showed that this lethality could not be rescued by administration of ghrelin or growth hormone. We then initiated a biochemical fractionation of a high-molecular-weight leptin complex from human plasma and identified clusterin as a major component of this leptin-containing complex. However, in contrast to previous reports, we failed to observe a leptin-potentiating effect of either exogenous or endogenous clusterin, and parabiosis of db clusterin−/− double-mutant to WT mice still caused lethality. Intriguingly, in parabiotic pairs of two WT mice, leptin infusion into one of the mice led to an enhanced starvation response during calorie restriction as evidenced by increased plasma ghrelin and growth-hormone levels. Moreover, leptin treatment resulted in death of the parabiotic pairs. These data suggest that the appetite suppression in WT mice after parabiosis to db mutants is the result of induced hyperleptinemia combined with the stress or other aspect(s) of the parabiosis procedure. PMID:26150485

A Novel Intergenic ETnII-β Insertion Mutation Causes Multiple Malformations in Polypodia Mice

PubMed Central

Lehoczky, Jessica A.; Thomas, Peedikayil E.; Patrie, Kevin M.; Owens, Kailey M.; Villarreal, Lisa M.; Galbraith, Kenneth; Washburn, Joe; Johnson, Craig N.; Gavino, Bryant; Borowsky, Alexander D.; Millen, Kathleen J.; Wakenight, Paul; Law, William; Van Keuren, Margaret L.; Gavrilina, Galina; Hughes, Elizabeth D.; Saunders, Thomas L.; Brihn, Lesil; Nadeau, Joseph H.; Innis, Jeffrey W.

2013-01-01

Mouse early transposon insertions are responsible for ∼10% of spontaneous mutant phenotypes. We previously reported the phenotypes and genetic mapping of Polypodia, (Ppd), a spontaneous, X-linked dominant mutation with profound effects on body plan morphogenesis. Our new data shows that mutant mice are not born in expected Mendelian ratios secondary to loss after E9.5. In addition, we refined the Ppd genetic interval and discovered a novel ETnII-β early transposon insertion between the genes for Dusp9 and Pnck. The ETn inserted 1.6 kb downstream and antisense to Dusp9 and does not disrupt polyadenylation or splicing of either gene. Knock-in mice engineered to carry the ETn display Ppd characteristic ectopic caudal limb phenotypes, showing that the ETn insertion is the Ppd molecular lesion. Early transposons are actively expressed in the early blastocyst. To explore the consequences of the ETn on the genomic landscape at an early stage of development, we compared interval gene expression between wild-type and mutant ES cells. Mutant ES cell expression analysis revealed marked upregulation of Dusp9 mRNA and protein expression. Evaluation of the 5′ LTR CpG methylation state in adult mice revealed no correlation with the occurrence or severity of Ppd phenotypes at birth. Thus, the broad range of phenotypes observed in this mutant is secondary to a novel intergenic ETn insertion whose effects include dysregulation of nearby interval gene expression at early stages of development. PMID:24339789

Immunogenicity and protective efficacy of the Mycobacterium tuberculosis fadD26 mutant

PubMed Central

Infante, E; Aguilar, L D; Gicquel, B; Pando, R Hernandez

2005-01-01

The Mycobacterium tuberculosis fadD26 mutant has impaired synthesis of phthiocerol dimycocerosates (DIM) and is attenuated in BALB/c mice. Survival analysis following direct intratracheal infection confirmed the attenuation: 60% survival at 4 months post-infection versus 100% mortality at 9 weeks post-infection with the wild-type strain. The fadD26 mutant induced less pneumonia and larger DTH reactions. It induced lower but progressive production of interferon (IFN)-γ, interleukin (IL)-4 and tumour necrosis factor (TNF)-α. Used as a subcutaneous vaccine 60 days before intratracheal challenge with a hypervirulent strain of M. tuberculosis (Beijing code 9501000), the mutant induced a higher level of protection than did Bacille Calmette–Guérin (BCG). Seventy per cent of the mice vaccinated with the fadD26 mutant survived at 16 weeks after challenge compared to 30% of those vaccinated with BCG. Similarly, there was less tissue damage (pneumonia) and lower colony-forming units (CFU) in the mice vaccinated with the fadD26 mutant compared to the findings in mice vaccinated with BCG. These data suggest that DIM synthesis is important for the pathogenicity of M. tuberculosis, and that inactivation of DIM synthesis can increase the immunogenicity of live vaccines, and increase their ability to protect against tuberculosis. PMID:15958066

Psychotropic effects of Lactobacillus plantarum PS128 in early life-stressed and naïve adult mice.

PubMed

Liu, Yen-Wenn; Liu, Wei-Hsien; Wu, Chien-Chen; Juan, Yi-Chen; Wu, Yu-Chen; Tsai, Huei-Ping; Wang, Sabrina; Tsai, Ying-Chieh

2016-01-15

Ingestion of specific probiotics, namely "psychobiotics", produces psychotropic effects on behavior and affects the hypothalamic-pituitary-adrenal axis and neurochemicals in the brain. We examined the psychotropic effects of a potential psychobiotic bacterium, Lactobacillus plantarum strain PS128 (PS128), on mice subjected to early life stress (ELS) and on naïve adult mice. Behavioral tests revealed that chronic ingestion of PS128 increased the locomotor activities in both ELS and naïve adult mice in the open field test. In the elevated plus maze, PS128 significantly reduced the anxiety-like behaviors in naïve adult mice but not in the ELS mice; whereas the depression-like behaviors were reduced in ELS mice but not in naïve mice in forced swimming test and sucrose preference test. PS128 administration also reduced ELS-induced elevation of serum corticosterone under both basal and stressed states but had no effect on naïve mice. In addition, PS128 reduced inflammatory cytokine levels and increased anti-inflammatory cytokine level in the serum of ELS mice. Furthermore, the dopamine level in the prefrontal cortex (PFC) was significantly increased in PS128 treated ELS and naïve adult mice whereas serotonin (5-HT) level was increased only in the naïve adult mice. These results suggest that chronic ingestion of PS128 could ameliorate anxiety- and depression-like behaviors and modulate neurochemicals related to affective disorders. Thus PS128 shows psychotropic properties and has great potential for improving stress-related symptoms. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

SREB2/GPR85, a schizophrenia risk factor, negatively regulates hippocampal adult neurogenesis and neurogenesis-dependent learning and memory.

PubMed

Chen, Qian; Kogan, Jeffrey H; Gross, Adam K; Zhou, Yuan; Walton, Noah M; Shin, Rick; Heusner, Carrie L; Miyake, Shinichi; Tajinda, Katsunori; Tamura, Kouichi; Matsumoto, Mitsuyuki

2012-09-01

SREB2/GPR85, a member of the super-conserved receptor expressed in brain (SREB) family, is the most conserved G-protein-coupled receptor in vertebrate evolution. Previous human and mouse genetic studies have indicated a possible link between SREB2 and schizophrenia. SREB2 is robustly expressed in the hippocampal formation, especially in the dentate gyrus, a structure with an established involvement in psychiatric disorders and cognition. However, the function of SREB2 in the hippocampus remains elusive. Here we show that SREB2 regulates hippocampal adult neurogenesis, which impacts on cognitive function. Bromodeoxyuridine incorporation and immunohistochemistry were conducted in SREB2 transgenic (Tg, over-expression) and knockout (KO, null-mutant) mice to quantitatively assay adult neurogenesis and newborn neuron dendritic morphology. Cognitive responses associated with adult neurogenesis alteration were evaluated in SREB2 mutant mice. In SREB2 Tg mice, both new cell proliferation and new neuron survival were decreased in the dentate gyrus, whereas an enhancement of new neuron survival occurred in SREB2 KO mouse dentate gyrus. Doublecortin staining revealed dendritic morphology deficits of newly generated neurons in SREB2 Tg mice. In a spatial pattern separation task, SREB2 Tg mice displayed a decreased ability to discriminate spatial relationships, whereas SREB2 KO mice had enhanced abilities in this task. Additionally, SREB2 Tg and KO mice had reciprocal phenotypes in a Y-maze working memory task. Our results indicate that SREB2 is a negative regulator of adult neurogenesis and consequential cognitive functions. Inhibition of SREB2 function may be a novel approach to enhance hippocampal adult neurogenesis and cognitive abilities to ameliorate core symptoms of psychiatric patients. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

A miniature mechanical ventilator for newborn mice.

PubMed

Kolandaivelu, K; Poon, C S

1998-02-01

Transgenic/knockout mice with pre-defined mutations have become increasingly popular in biomedical research as models of human diseases. In some instances, the resulting mutation may cause cardiorespiratory distress in the neonatal or adult animals and may necessitate resuscitation. Here we describe the design and testing of a miniature and versatile ventilator that can deliver varying ventilatory support modes, including conventional mechanical ventilation and high-frequency ventilation, to animals as small as the newborn mouse. With a double-piston body chamber design, the device circumvents the problem of air leakage and obviates the need for invasive procedures such as endotracheal intubation, which are particularly important in ventilating small animals. Preliminary tests on newborn mice as early as postnatal day O demonstrated satisfactory restoration of pulmonary ventilation and the prevention of respiratory failure in mutant mice that are prone to respiratory depression. This device may prove useful in the postnatal management of transgenic/knockout mice with genetically inflicted respiratory disorders.

Rational design of a live attenuated dengue vaccine: 2'-o-methyltransferase mutants are highly attenuated and immunogenic in mice and macaques.

PubMed

Züst, Roland; Dong, Hongping; Li, Xiao-Feng; Chang, David C; Zhang, Bo; Balakrishnan, Thavamalar; Toh, Ying-Xiu; Jiang, Tao; Li, Shi-Hua; Deng, Yong-Qiang; Ellis, Brett R; Ellis, Esther M; Poidinger, Michael; Zolezzi, Francesca; Qin, Cheng-Feng; Shi, Pei-Yong; Fink, Katja

2013-01-01

Dengue virus is transmitted by Aedes mosquitoes and infects at least 100 million people every year. Progressive urbanization in Asia and South-Central America and the geographic expansion of Aedes mosquito habitats have accelerated the global spread of dengue, resulting in a continuously increasing number of cases. A cost-effective, safe vaccine conferring protection with ideally a single injection could stop dengue transmission. Current vaccine candidates require several booster injections or do not provide protection against all four serotypes. Here we demonstrate that dengue virus mutants lacking 2'-O-methyltransferase activity are highly sensitive to type I IFN inhibition. The mutant viruses are attenuated in mice and rhesus monkeys and elicit a strong adaptive immune response. Monkeys immunized with a single dose of 2'-O-methyltransferase mutant virus showed 100% sero-conversion even when a dose as low as 1,000 plaque forming units was administrated. Animals were fully protected against a homologous challenge. Furthermore, mosquitoes feeding on blood containing the mutant virus were not infected, whereas those feeding on blood containing wild-type virus were infected and thus able to transmit it. These results show the potential of 2'-O-methyltransferase mutant virus as a safe, rationally designed dengue vaccine that restrains itself due to the increased susceptibility to the host's innate immune response.

Imaginal Disc Abnormalities in Lethal Mutants of Drosophila

PubMed Central

Shearn, Allen; Rice, Thomas; Garen, Alan; Gehring, Walter

1971-01-01

Late lethal mutants of Drosophila melanogaster, dying after the larval stage of development, were isolated. The homozygous mutant larvae were examined for abnormal imaginal disc morphology, and the discs were injected into normal larval hosts to test their capacities to differentiate into adult structures. In about half of the mutants analyzed, disc abnormalities were found. Included among the abnormalities were missing discs, small discs incapable of differentiating, morphologically normal discs with limited capacities for differentiation, and discs with homeotic transformations. In some mutants all discs were affected, and in others only certain discs. The most extreme abnormal phenotype is a class of “discless” mutants. The viability of these mutant larvae indicates that the discs are essential only for the development of an adult and not of a larva. The late lethals are therefore a major source of mutants for studying the genetic control of disc formation. Images PMID:5002822

Abnormal iron metabolism and oxidative stress in mice expressing a mutant form of the ferritin light polypeptide gene

PubMed Central

Barbeito, Ana G.; Garringer, Holly J.; Baraibar, Martin A.; Gao, Xiaoying; Arredondo, Miguel; Núñez, Marco T.; Smith, Mark A.; Ghetti, Bernardino; Vidal, Ruben

2009-01-01

Insertional mutations in exon 4 of the ferritin light chain (FTL) gene are associated with hereditary ferritinopathy (HF) or neuroferritinopathy, an autosomal dominant neurodegenerative disease characterized by progressive impairment of motor and cognitive functions. To determine the pathogenic mechanisms by which mutations in FTL lead to neurodegeneration, we investigated iron metabolism and markers of oxidative stress in the brain of transgenic (Tg) mice that express the mutant human FTL498-499InsTC cDNA. Compared with wild-type mice, brain extracts from Tg (FTL-Tg) mice showed an increase in the cytoplasmic levels of both FTL and ferritin heavy chain polypeptides, a decrease in the protein and mRNA levels of transferrin receptor-1, and a significant increase in iron levels. Transgenic mice also showed the presence of markers for lipid peroxidation, protein carbonyls, and nitrone–protein adducts in the brain. However, gene expression analysis of iron management proteins in the liver of Tg mice indicates that the FTL-Tg mouse liver is iron deficient. Our data suggest that disruption of iron metabolism in the brain has a primary role in the process of neurodegeneration in HF and that the pathogenesis of HF is likely to result from a combination of reduction in iron storage function and enhanced toxicity associated with iron-induced ferritin aggregates in the brain. PMID:19519778

Fast neutron irradiation deteriorates hippocampus-related memory ability in adult mice.

PubMed

Yang, Miyoung; Kim, Hwanseong; Kim, Juhwan; Kim, Sung-Ho; Kim, Jong-Choon; Bae, Chun-Sik; Kim, Joong-Sun; Shin, Taekyun; Moon, Changjong

2012-03-01

Object recognition memory and contextual fear conditioning task performance in adult C57BL/6 mice exposed to cranial fast neutron irradiation (0.8 Gy) were examined to evaluate hippocampus-related behavioral dysfunction following acute exposure to relatively low doses of fast neutrons. In addition, hippocampal neurogenesis changes in adult murine brain after cranial irradiation were analyzed using the neurogenesis immunohistochemical markers Ki-67 and doublecortin (DCX). In the object recognition memory test and contextual fear conditioning, mice trained 1 and 7 days after irradiation displayed significant memory deficits compared to the sham-irradiated controls. The number of Ki-67- and DCX-positive cells decreased significantly 24 h post-irradiation. These results indicate that acute exposure of the adult mouse brain to a relatively low dose of fast neutrons interrupts hippocampal functions, including learning and memory, possibly by inhibiting neurogenesis.

Spinocerebellar ataxia type 6 knockin mice develop a progressive neuronal dysfunction with age-dependent accumulation of mutant CaV2.1 channels

PubMed Central

Watase, Kei; Barrett, Curtis F.; Miyazaki, Taisuke; Ishiguro, Taro; Ishikawa, Kinya; Hu, Yuanxin; Unno, Toshinori; Sun, Yaling; Kasai, Sayumi; Watanabe, Masahiko; Gomez, Christopher M.; Mizusawa, Hidehiro; Tsien, Richard W.; Zoghbi, Huda Y.

2008-01-01

Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disorder caused by CAG repeat expansions within the voltage-gated calcium (CaV) 2.1 channel gene. It remains controversial whether the mutation exerts neurotoxicity by changing the function of CaV2.1 channel or through a gain-of-function mechanism associated with accumulation of the expanded polyglutamine protein. We generated three strains of knockin (KI) mice carrying normal, expanded, or hyperexpanded CAG repeat tracts in the Cacna1a locus. The mice expressing hyperexpanded polyglutamine (Sca684Q) developed progressive motor impairment and aggregation of mutant CaV2.1 channels. Electrophysiological analysis of cerebellar Purkinje cells revealed similar Ca2+ channel current density among the three KI models. Neither voltage sensitivity of activation nor inactivation was altered in the Sca684Q neurons, suggesting that expanded CAG repeat per se does not affect the intrinsic electrophysiological properties of the channels. The pathogenesis of SCA6 is apparently linked to an age-dependent process accompanied by accumulation of mutant CaV2.1 channels. PMID:18687887

Prefrontal cortical-specific differences in behavior and synaptic plasticity between adolescent and adult mice.

PubMed

Konstantoudaki, Xanthippi; Chalkiadaki, Kleanthi; Vasileiou, Elisabeth; Kalemaki, Katerina; Karagogeos, Domna; Sidiropoulou, Kyriaki

2018-03-01

Adolescence is a highly vulnerable period for the emergence of major neuropsychological disorders and is characterized by decreased cognitive control and increased risk-taking behavior and novelty-seeking. The prefrontal cortex (PFC) is involved in the cognitive control of impulsive and risky behavior. Although the PFC is known to reach maturation later than other cortical areas, little information is available regarding the functional changes from adolescence to adulthood in PFC, particularly compared with other primary cortical areas. This study aims to understand the development of PFC-mediated, compared with non-PFC-mediated, cognitive functions. Toward this aim, we performed cognitive behavioral tasks in adolescent and adult mice and subsequently investigated synaptic plasticity in two different cortical areas. Our results showed that adolescent mice exhibit impaired performance in PFC-dependent cognitive tasks compared with adult mice, whereas their performance in non-PFC-dependent tasks is similar to that of adults. Furthermore, adolescent mice exhibited decreased long-term potentiation (LTP) within upper-layer synapses of the PFC but not the barrel cortex. Blocking GABA A receptor function significantly augments LTP in both the adolescent and adult PFC. No change in intrinsic excitability of PFC pyramidal neurons was observed between adolescent and adult mice. Finally, increased expression of the NR2A subunit of the N-methyl-d-aspartate receptors is found only in the adult PFC, a change that could underlie the emergence of LTP. In conclusion, our results demonstrate physiological and behavioral changes during adolescence that are specific to the PFC and could underlie the reduced cognitive control in adolescents. NEW & NOTEWORTHY This study reports that adolescent mice exhibit impaired performance in cognitive functions dependent on the prefrontal cortex but not in cognitive functions dependent on other cortical regions. The current results propose reduced

Intact interval timing in circadian CLOCK mutants.

PubMed

Cordes, Sara; Gallistel, C R

2008-08-28

While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval-timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/- and -/- mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing.

Haemolysis and Perturbations in the Systemic Iron Metabolism of Suckling, Copper-Deficient Mosaic Mutant Mice – An Animal Model of Menkes Disease

PubMed Central

Lenartowicz, Małgorzata; Starzyński, Rafał R.; Krzeptowski, Wojciech; Grzmil, Paweł; Bednarz, Aleksandra; Ogórek, Mateusz; Pierzchała, Olga; Staroń, Robert; Gajowiak, Anna; Lipiński, Paweł

2014-01-01

The biological interaction between copper and iron is best exemplified by the decreased activity of multicopper ferroxidases under conditions of copper deficiency that limits the availability of iron for erythropoiesis. However, little is known about how copper deficiency affects iron homeostasis through alteration of the activity of other copper-containing proteins, not directly connected with iron metabolism, such as superoxide dismutase 1 (SOD1). This antioxidant enzyme scavenges the superoxide anion, a reactive oxygen species contributing to the toxicity of iron via the Fenton reaction. Here, we analyzed changes in the systemic iron metabolism using an animal model of Menkes disease: copper-deficient mosaic mutant mice with dysfunction of the ATP7A copper transporter. We found that the erythrocytes of these mutants are copper-deficient, display decreased SOD1 activity/expression and have cell membrane abnormalities. In consequence, the mosaic mice show evidence of haemolysis accompanied by haptoglobin-dependent elimination of haemoglobin (Hb) from the circulation, as well as the induction of haem oxygenase 1 (HO1) in the liver and kidney. Moreover, the hepcidin-ferroportin regulatory axis is strongly affected in mosaic mice. These findings indicate that haemolysis is an additional pathogenic factor in a mouse model of Menkes diseases and provides evidence of a new indirect connection between copper deficiency and iron metabolism. PMID:25247420

Loss of Either Rac1 or Rac3 GTPase Differentially Affects the Behavior of Mutant Mice and the Development of Functional GABAergic Networks

PubMed Central

Pennucci, Roberta; Talpo, Francesca; Astro, Veronica; Montinaro, Valentina; Morè, Lorenzo; Cursi, Marco; Castoldi, Valerio; Chiaretti, Sara; Bianchi, Veronica; Marenna, Silvia; Cambiaghi, Marco; Tonoli, Diletta; Leocani, Letizia; Biella, Gerardo; D'Adamo, Patrizia; de Curtis, Ivan

2016-01-01

Rac GTPases regulate the development of cortical/hippocampal GABAergic interneurons by affecting the early development and migration of GABAergic precursors. We have addressed the function of Rac1 and Rac3 proteins during the late maturation of hippocampal interneurons. We observed specific phenotypic differences between conditional Rac1 and full Rac3 knockout mice. Rac1 deletion caused greater generalized hyperactivity and cognitive impairment compared with Rac3 deletion. This phenotype matched with a more evident functional impairment of the inhibitory circuits in Rac1 mutants, showing higher excitability and reduced spontaneous inhibitory currents in the CA hippocampal pyramidal neurons. Morphological analysis confirmed a differential modification of the inhibitory circuits: deletion of either Rac caused a similar reduction of parvalbumin-positive inhibitory terminals in the pyramidal layer. Intriguingly, cannabinoid receptor-1-positive terminals were strongly increased only in the CA1 of Rac1-depleted mice. This increase may underlie the stronger electrophysiological defects in this mutant. Accordingly, incubation with an antagonist for cannabinoid receptors partially rescued the reduction of spontaneous inhibitory currents in the pyramidal cells of Rac1 mutants. Our results show that Rac1 and Rac3 have independent roles in the formation of GABAergic circuits, as highlighted by the differential effects of their deletion on the late maturation of specific populations of interneurons. PMID:26582364

Genetic background effects in Neuroligin-3 mutant mice: Minimal behavioral abnormalities on C57 background.

PubMed

Jaramillo, Thomas C; Escamilla, Christine Ochoa; Liu, Shunan; Peca, Lauren; Birnbaum, Shari G; Powell, Craig M

2018-02-01

Neuroligin-3 (NLGN3) is a postsynaptic cell adhesion protein that interacts with presynaptic ligands including neurexin-1 (NRXN1) [Ichtchenko et al., Journal of Biological Chemistry, 271, 2676-2682, 1996]. Mice harboring a mutation in the NLGN3 gene (NL3R451C) mimicking a mutation found in two brothers with autism spectrum disorder (ASD) were previously generated and behaviorally phenotyped for autism-related behaviors. In these NL3R451C mice generated and tested on a hybrid C57BL6J/129S2/SvPasCrl background, we observed enhanced spatial memory and reduced social interaction [Tabuchi et al., Science, 318, 71-76, 2007]. Curiously, an independently generated second line of mice harboring the same mutation on a C57BL6J background exhibited minimal aberrant behavior, thereby providing apparently discrepant results. To investigate the origin of the discrepancy, we previously replicated the original findings of Tabuchi et al. by studying the same NL3R451C mutation on a pure 129S2/SvPasCrl genetic background. Here we complete the behavioral characterization of the NL3R451C mutation on a pure C57BL6J genetic background to determine if background genetics play a role in the discrepant behavioral outcomes involving NL3R451C mice. NL3R451C mutant mice on a pure C57BL6J background did not display spatial memory enhancements or social interaction deficits. We only observed a decreased startle response and mildly increased locomotor activity in these mice suggesting that background genetics influences behavioral outcomes involving the NL3R451C mutation. Autism Res 2018, 11: 234-244. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Behavioral symptoms of autism can be highly variable, even in cases that involve identical genetic mutations. Previous studies in mice with a mutation of the Neuroligin-3 gene showed enhanced learning and social deficits. We replicated these findings on the same and different genetic backgrounds. In this study, however, the

Mutant soluble ectodomain of fibroblast growth factor receptor-2 IIIc attenuates bleomycin-induced pulmonary fibrosis in mice.

PubMed

Yu, Zhi-hong; Wang, Ding-ding; Zhou, Zhi-you; He, Shui-lian; Chen, An-an; Wang, Ju

2012-01-01

We have developed a strong inhibitor (S252W mutant soluble ectodomain of fibroblast growth factor recptor-2 IIIc, msFGFR2) that binds FGFs strongly and blocks the activation of FGFRs. In vitro, msFGFR2 could inhibit the promoting effect of transforming growth factor (TGF)-β1 on the proliferation of primary lung fibroblasts. In vivo, msFGFR2 alleviated lung fibrosis through inhibiting the expression of α-smooth muscle actin (SMA) and collagen deposit. In Western blotting of the right lung tissues and immunohistochemical assay, we found the level of p-FGFRs, p-mitogen activated protein kinase (MAPK) and p-Smad3 in the mice of bleomycin (BLM) group treated with msFGFR2 was down dramatically compared with the mice of BLM group, which suggested the activations of FGF and TGF-β signals were blocked meanwhile. In summary, msFGFR2 attenuated BLM-induced fibrosis and is an attractive therapeutic candidate for human pulmonary fibrosis.

A novel candidate gene for mouse and human preaxial polydactyly with altered expression in limbs of Hemimelic extra-toes mutant mice.

PubMed

Clark, R M; Marker, P C; Kingsley, D M

2000-07-01

Polydactyly is a common malformation of vertebrate limbs. In humans a major locus for nonsyndromic pre-axial polydactyly (PPD) has been mapped previously to 7q36. The mouse Hemimelic extra-toes (Hx) mutation maps to a homologous chromosome segment and has been proposed to affect a homologous gene. To understand the molecular changes underlying PPD, we used a positional cloning approach to identify the gene or genes disrupted by the Hx mutation and a closely linked limb mutation, Hammertoe (Hm). High resolution genetic mapping identified a small candidate interval for the mouse mutations located 1.2 cM distal to the Shh locus. The nonrecombinant interval was completely cloned in bacterial artificial chromosomes and searched for genes using a combination of exon trapping, sample sequencing, and mapping of known genes. Two novel genes, Lmbr1 and Lmbr2, are entirely within the candidate interval we defined genetically. The open reading frame of both genes is intact in mutant mice, but the expression of the Lmbr1 gene is dramatically altered in developing limbs of Hx mutant mice. The correspondence between the spatial and temporal changes in Lmbr1 expression and the embryonic onset of the Hx mutant phenotype suggests that the mouse Hx mutation may be a regulatory allele of Lmbr1. The human ortholog of Lmbr1 maps within the recently described interval for human PPD, strengthening the possibility that both mouse and human limb abnormalities are due to defects in the same highly conserved gene.

Are Sema5a mutant mice a good model of autism? A behavioral analysis of sensory systems, emotionality and cognition

PubMed Central

Gunn, Rhian K.; Huentelman, Matthew J.; Brown, Richard E.

2011-01-01

Semaphorin 5A (Sema5A) expression is reduced in the brain of individuals with autism, thus mice with reduced Sema5A levels may serve as a model of this neurodevelopmental disorder. We tested male and female Sema5a knockout mice (B6.129P2SEMA5A/J) and C57BL/6J controls for emotionality, visual ability, prepulse inhibition, motor learning and cognition. Overall, there were only two genotype differences in emotionality: Sema5a mutant mice had more stretch-attend postures in the elevated plus-maze and more defecations in the open field. All mice could see, but Sema5a mice had better visual ability than C57BL/6J mice. There were no genotype differences in sensory-motor gating. Sema5a mice showed higher levels of activity in the elevated plus-maze and light/dark transition box, and there were sex by genotype differences in the Rotarod, suggesting a sex difference in balance and coordination differentially affected by Sema5a. There were no genotype effects on cognition: Sema5a mice did not differ from C57BL/6J in the Morris water maze, set-shifting or cued and contextual fear conditioning. In the social recognition test, all mice preferred social stimuli, but there was no preference for social novelty, thus the Sema5A mice do not have a deficit in social behavior. Overall, there were a number of sex differences, with females showing greater activity and males performing better in tests of spatial learning and memory, but no deficits in the behavior of Sema5A mice. We conclude that the Sema5a mice do not meet the behavioral criteria for a mouse model of autism. PMID:21777623

Cardiac hypertrophy limits infarct expansion after myocardial infarction in mice.

PubMed

Iismaa, Siiri E; Li, Ming; Kesteven, Scott; Wu, Jianxin; Chan, Andrea Y; Holman, Sara R; Calvert, John W; Haq, Ahtesham Ul; Nicks, Amy M; Naqvi, Nawazish; Husain, Ahsan; Feneley, Michael P; Graham, Robert M

2018-04-17

We have previously demonstrated that adult transgenic C57BL/6J mice with CM-restricted overexpression of the dominant negative W v mutant protein (dn-c-kit-Tg) respond to pressure overload with robust cardiomyocyte (CM) cell cycle entry. Here, we tested if outcomes after myocardial infarction (MI) due to coronary artery ligation are improved in this transgenic model. Compared to non-transgenic littermates (NTLs), adult male dn-c-kit-Tg mice displayed CM hypertrophy and concentric left ventricular (LV) hypertrophy in the absence of an increase in workload. Stroke volume and cardiac output were preserved and LV wall stress was markedly lower than that in NTLs, leading to a more energy-efficient heart. In response to MI, infarct size in adult (16-week old) dn-c-kit-Tg hearts was similar to that of NTL after 24 h but was half that in NTL hearts 12 weeks post-MI. Cumulative CM cell cycle entry was only modestly increased in dn-c-kit-Tg hearts. However, dn-c-kit-Tg mice were more resistant to infarct expansion, adverse LV remodelling and contractile dysfunction, and suffered no early death from LV rupture, relative to NTL mice. Thus, pre-existing cardiac hypertrophy lowers wall stress in dn-c-kit-Tg hearts, limits infarct expansion and prevents death from myocardial rupture.

Establishment of a tamoxifen-inducible Cre-driver mouse strain for widespread and temporal genetic modification in adult mice.

PubMed

Ichise, Hirotake; Hori, Akiko; Shiozawa, Seiji; Kondo, Saki; Kanegae, Yumi; Saito, Izumu; Ichise, Taeko; Yoshida, Nobuaki

2016-07-29

Temporal genetic modification of mice using the ligand-inducible Cre/loxP system is an important technique that allows the bypass of embryonic lethal phenotypes and access to adult phenotypes. In this study, we generated a tamoxifen-inducible Cre-driver mouse strain for the purpose of widespread and temporal Cre recombination. The new line, named CM32, expresses the GFPneo-fusion gene in a wide variety of tissues before FLP recombination and tamoxifen-inducible Cre after FLP recombination. Using FLP-recombined CM32 mice (CM32Δ mice) and Cre reporter mouse lines, we evaluated the efficiency of Cre recombination with and without tamoxifen administration to adult mice, and found tamoxifen-dependent induction of Cre recombination in a variety of adult tissues. In addition, we demonstrated that conditional activation of an oncogene could be achieved in adults using CM32Δ mice. CM32Δ;T26 mice, which harbored a Cre recombination-driven, SV40 large T antigen-expressing transgene, were viable and fertile. No overt phenotype was found in the mice up to 3 months after birth. Although they displayed pineoblastomas (pinealoblastomas) and/or thymic enlargement due to background Cre recombination by 6 months after birth, they developed epidermal hyperplasia when administered tamoxifen. Collectively, our results suggest that the CM32Δ transgenic mouse line can be applied to the assessment of adult phenotypes in mice with loxP-flanked transgenes.

The subcutaneous inoculation of pH 6 antigen mutants of Yersinia pestis does not affect virulence and immune response in mice.

PubMed

Anisimov, Andrey P; Bakhteeva, Irina V; Panfertsev, Evgeniy A; Svetoch, Tat'yana E; Kravchenko, Tat'yana B; Platonov, Mikhail E; Titareva, Galina M; Kombarova, Tat'yana I; Ivanov, Sergey A; Rakin, Alexander V; Amoako, Kingsley K; Dentovskaya, Svetlana V

2009-01-01

Two isogenic sets of Yersinia pestis strains were generated, composed of wild-type strains 231 and I-1996, their non-polar pH 6(-) mutants with deletions in the psaA gene that codes for its structural subunit or the whole operon, as well as strains with restored ability for temperature- and pH-dependent synthesis of adhesion pili or constitutive production of pH 6 antigen. The mutants were generated by site-directed mutagenesis of the psa operon and subsequent complementation in trans. It was shown that the loss of synthesis or constitutive production of pH 6 antigen did not influence Y. pestis virulence or the average survival time of subcutaneously inoculated BALB/c naïve mice or animals immunized with this antigen.

Intact Interval Timing in Circadian CLOCK Mutants

PubMed Central

Cordes, Sara; Gallistel, C. R.

2008-01-01

While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/− and −/− mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing. PMID:18602902

The clock gene Period1 regulates innate routine behaviour in mice.

PubMed

Bechstein, Philipp; Rehbach, Nils-Jörn; Yuhasingham, Gowzekan; Schürmann, Christoph; Göpfert, Melanie; Kössl, Manfred; Maronde, Erik

2014-04-22

Laboratory mice are well capable of performing innate routine behaviour programmes necessary for courtship, nest-building and exploratory activities although housed for decades in animal facilities. We found that in mice inactivation of the clock gene Period1 profoundly changes innate routine behaviour programmes like those necessary for courtship, nest building, exploration and learning. These results in wild-type and Period1 mutant mice, together with earlier findings on courtship behaviour in wild-type and period-mutant Drosophila melanogaster, suggest a conserved role of Period-genes on innate routine behaviour. Additionally, both per-mutant flies and Period1-mutant mice display spatial learning and memory deficits. The profound influence of Period1 on routine behaviour programmes in mice, including female partner choice, may be independent of its function as a circadian clock gene, since Period1-deficient mice display normal circadian behaviour.

Postnatal colonization with human "infant-type" Bifidobacterium species alters behavior of adult gnotobiotic mice.

PubMed

Luk, Berkley; Veeraragavan, Surabi; Engevik, Melinda; Balderas, Miriam; Major, Angela; Runge, Jessica; Luna, Ruth Ann; Versalovic, James

2018-01-01

Accumulating studies have defined a role for the intestinal microbiota in modulation of host behavior. Research using gnotobiotic mice emphasizes that early microbial colonization with a complex microbiota (conventionalization) can rescue some of the behavioral abnormalities observed in mice that grow to adulthood completely devoid of bacteria (germ-free mice). However, the human infant and adult microbiomes vary greatly, and effects of the neonatal microbiome on neurodevelopment are currently not well understood. Microbe-mediated modulation of neural circuit patterning in the brain during neurodevelopment may have significant long-term implications that we are only beginning to appreciate. Modulation of the host central nervous system by the early-life microbiota is predicted to have pervasive and lasting effects on brain function and behavior. We sought to replicate this early microbe-host interaction by colonizing gnotobiotic mice at the neonatal stage with a simplified model of the human infant gut microbiota. This model consortium consisted of four "infant-type" Bifidobacterium species known to be commensal members of the human infant microbiota present in high abundance during postnatal development. Germ-free mice and mice neonatally-colonized with a complex, conventional murine microbiota were used for comparison. Motor and non-motor behaviors of the mice were tested at 6-7 weeks of age, and colonization patterns were characterized by 16S ribosomal RNA gene sequencing. Adult germ-free mice were observed to have abnormal memory, sociability, anxiety-like behaviors, and motor performance. Conventionalization at the neonatal stage rescued these behavioral abnormalities, and mice colonized with Bifidobacterium spp. also exhibited important behavioral differences relative to the germ-free controls. The ability of Bifidobacterium spp. to improve the recognition memory of both male and female germ-free mice was a prominent finding. Together, these data demonstrate

Paternal Aging Affects Behavior in Pax6 Mutant Mice: A Gene/Environment Interaction in Understanding Neurodevelopmental Disorders.

PubMed

Yoshizaki, Kaichi; Furuse, Tamio; Kimura, Ryuichi; Tucci, Valter; Kaneda, Hideki; Wakana, Shigeharu; Osumi, Noriko

2016-01-01

Neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit and hyperactivity disorder (ADHD) have increased over the last few decades. These neurodevelopmental disorders are characterized by a complex etiology, which involves multiple genes and gene-environmental interactions. Various genes that control specific properties of neural development exert pivotal roles in the occurrence and severity of phenotypes associated with neurodevelopmental disorders. Moreover, paternal aging has been reported as one of the factors that contribute to the risk of ASD and ADHD. Here we report, for the first time, that paternal aging has profound effects on the onset of behavioral abnormalities in mice carrying a mutation of Pax6, a gene with neurodevelopmental regulatory functions. We adopted an in vitro fertilization approach to restrict the influence of additional factors. Comprehensive behavioral analyses were performed in Sey/+ mice (i.e., Pax6 mutant heterozygotes) born from in vitro fertilization of sperm taken from young or aged Sey/+ fathers. No body weight changes were found in the four groups, i.e., Sey/+ and wild type (WT) mice born to young or aged father. However, we found important differences in maternal separation-induced ultrasonic vocalizations of Sey/+ mice born from young father and in the level of hyperactivity of Sey/+ mice born from aged fathers in the open-field test, respectively, compared to WT littermates. Phenotypes of anxiety were observed in both genotypes born from aged fathers compared with those born from young fathers. No significant difference was found in social behavior and sensorimotor gating among the four groups. These results indicate that mice with a single genetic risk factor can develop different phenotypes depending on the paternal age. Our study advocates for serious considerations on the role of paternal aging in breeding strategies for animal studies.

A novel p53 mutational hotspot in skin tumors from UV-irradiated Xpc mutant mice alters transactivation functions.

PubMed

Inga, Alberto; Nahari, Dorit; Velasco-Miguel, Susana; Friedberg, Errol C; Resnick, Michael A

2002-08-22

A mutation in codon 122 of the mouse p53 gene resulting in a T to L amino acid substitution (T122-->L) is frequently associated with skin cancer in UV-irradiated mice that are both homozygous mutant for the nucleotide excision repair (NER) gene Xpc (Xpc(-/-)) and hemizygous mutant for the p53 gene. We investigated the functional consequences of the mouse T122-->L mutation when expressed either in mammalian cells or in the yeast Saccharomyces cerevisiae. Similar to a non-functional allele, high expression of the T122-->L allele in p53(-/-) mouse embryo fibroblasts and human Saos-2 cells failed to suppress growth. However, the T122-->L mutant p53 showed wild-type transactivation levels with Bax and MDM2 promoters when expressed in either cell type and retained transactivation of the p21 and the c-Fos promoters in one cell line. Using a recently developed rheostatable p53 induction system in yeast we assessed the T122-->L transactivation capacity at low levels of protein expression using 12 different p53 response elements (REs). Compared to wild-type p53 the T122-->L protein manifested an unusual transactivation pattern comprising reduced and enhanced activity with specific REs. The high incidence of the T122-->L mutant allele in the Xpc(-/-) background suggests that both genetic and epigenetic conditions may facilitate the emergence of particular functional p53 mutations. Furthermore, the approach that we have taken also provides for the dissection of functions that may be retained in many p53 tumor alleles.

Reduced alcohol consumption in mice lacking preprodynorphin.

PubMed Central

Blednov, Yuri A.; Walker, Danielle; Martinez, Marni; Harris., R. Adron

2007-01-01

Many studies suggest a role for endogenous opioid peptides and their receptors in regulation of ethanol intake. It is commonly accepted that the κ-opioid receptors and their endogenous ligands, dynorphins, produce a dysphoric state and therefore may be responsible for avoidance of alcohol. We used mutant mice lacking preprodynorphin in a variety of behavioral tests of alcohol actions. Null mutant female, but not male, mice showed significantly lower preference for alcohol and consumed lower amounts of alcohol in a two-bottle choice test as compared with wild-type littermates. In the same test, knockout mice of both sexes showed a strong reduction of preference for saccharin compared to control mice. In contrast, under conditions of limited (4 hours) access (light phase of the light/dark cycle), null mutant mice did not show any differences in consumption of saccharin but they showed significantly reduced intake of sucrose. To determine the possible cause for reduction of ethanol preference and intake, we studied other ethanol-related behaviors in mice lacking the preprodynorphin gene. There were no differences between null mutant and wild type mice in ethanol-induced loss of righting reflex, acute ethanol withdrawal, ethanol-induced conditioned place preference or conditioned taste aversion to ethanol. These results indicate that deletion of preprodynorphin leads to substantial reduction of alcohol intake in female mice, and suggest thath this is caused by decreased orosensory reward of alcohol (sweet taste and/or palatability). PMID:17307643

Reduced alcohol consumption in mice lacking preprodynorphin.

PubMed

Blednov, Yuri A; Walker, Danielle; Martinez, Marni; Harris, R Adron

2006-10-01

Many studies suggest a role for endogenous opioid peptides and their receptors in regulation of ethanol intake. It is commonly accepted that the kappa-opioid receptors and their endogenous ligands, dynorphins, produce a dysphoric state and therefore may be responsible for avoidance of alcohol. We used mutant mice lacking preprodynorphin in a variety of behavioral tests of alcohol actions. Null mutant female, but not male, mice showed significantly lower preference for alcohol and consumed lower amounts of alcohol in a two-bottle choice test as compared with wild-type littermates. In the same test, knockout mice of both sexes showed a strong reduction of preference for saccharin compared to control mice. In contrast, under conditions of limited (4 h) access (light phase of the light/dark cycle), null mutant mice did not show any differences in consumption of saccharin, but they showed significantly reduced intake of sucrose. To determine the possible cause for reduction of ethanol preference and intake, we studied other ethanol-related behaviors in mice lacking the preprodynorphin gene. There were no differences between null mutant and wild-type mice in ethanol-induced loss of righting reflex, acute ethanol withdrawal, ethanol-induced conditioned place preference, or conditioned taste aversion to ethanol. These results indicate that deletion of preprodynorphin leads to substantial reduction of alcohol intake in female mice, and suggest that this is caused by decreased orosensory reward of alcohol (sweet taste and/or palatability).

Lipofuscin accumulation, abnormal electrophysiology, and photoreceptor degeneration in mutant ELOVL4 transgenic mice: a model for macular degeneration.

PubMed

Karan, G; Lillo, C; Yang, Z; Cameron, D J; Locke, K G; Zhao, Y; Thirumalaichary, S; Li, C; Birch, D G; Vollmer-Snarr, H R; Williams, D S; Zhang, K

2005-03-15

Macular degeneration is a heterogeneous group of disorders characterized by photoreceptor degeneration and atrophy of the retinal pigment epithelium (RPE) in the central retina. An autosomal dominant form of Stargardt macular degeneration (STGD) is caused by mutations in ELOVL4, which is predicted to encode an enzyme involved in the elongation of long-chain fatty acids. We generated transgenic mice expressing a mutant form of human ELOVL4 that causes STGD. In these mice, we show that accumulation by the RPE of undigested phagosomes and lipofuscin, including the fluorophore, 2-[2,6-dimethyl-8-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1E,3E,5E,7E-octatetraenyl]-1-(2-hyydroxyethyl)-4-[4-methyl-6-(2,6,6,-trimethyl-1-cyclohexen-1-yl)-1E,3E,5E-hexatrienyl]-pyridinium (A2E) is followed by RPE atrophy. Subsequently, photoreceptor degeneration occurs in the central retina in a pattern closely resembling that of human STGD and age-related macular degeneration. The ELOVL4 transgenic mice thus provide a good model for both STGD and dry age-related macular degeneration, and represent a valuable tool for studies on therapeutic intervention in these forms of blindness.

Restoring auditory cortex plasticity in adult mice by restricting thalamic adenosine signaling

DOE PAGES

Blundon, Jay A.; Roy, Noah C.; Teubner, Brett J. W.; ...

2017-06-30

Circuits in the auditory cortex are highly susceptible to acoustic influences during an early postnatal critical period. The auditory cortex selectively expands neural representations of enriched acoustic stimuli, a process important for human language acquisition. Adults lack this plasticity. We show in the murine auditory cortex that juvenile plasticity can be reestablished in adulthood if acoustic stimuli are paired with disruption of ecto-5'-nucleotidase–dependent adenosine production or A1–adenosine receptor signaling in the auditory thalamus. This plasticity occurs at the level of cortical maps and individual neurons in the auditory cortex of awake adult mice and is associated with long-term improvement ofmore » tone-discrimination abilities. We determined that, in adult mice, disrupting adenosine signaling in the thalamus rejuvenates plasticity in the auditory cortex and improves auditory perception.« less

Restoring auditory cortex plasticity in adult mice by restricting thalamic adenosine signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blundon, Jay A.; Roy, Noah C.; Teubner, Brett J. W.

Circuits in the auditory cortex are highly susceptible to acoustic influences during an early postnatal critical period. The auditory cortex selectively expands neural representations of enriched acoustic stimuli, a process important for human language acquisition. Adults lack this plasticity. We show in the murine auditory cortex that juvenile plasticity can be reestablished in adulthood if acoustic stimuli are paired with disruption of ecto-5'-nucleotidase–dependent adenosine production or A1–adenosine receptor signaling in the auditory thalamus. This plasticity occurs at the level of cortical maps and individual neurons in the auditory cortex of awake adult mice and is associated with long-term improvement ofmore » tone-discrimination abilities. We determined that, in adult mice, disrupting adenosine signaling in the thalamus rejuvenates plasticity in the auditory cortex and improves auditory perception.« less

Differential Sensitivity to Ethanol-Induced Circadian Rhythm Disruption in Adolescent and Adult Mice

PubMed Central

Ruby, Christina L.; Palmer, Kaitlyn N.; Zhang, Jiawen; Risinger, Megan O.; Butkowski, Melissa A.; Swartzwelder, H. Scott

2016-01-01

Background Growing evidence supports a central role for the circadian system in alcohol use disorders, but few studies have examined this relationship during adolescence. In mammals, circadian rhythms are regulated by the suprachiasmatic nucleus (SCN), a biological clock whose timing is synchronized (reset) to the environment primarily by light (photic) input. Alcohol (ethanol) disrupts circadian timing in part by attenuating photic phase-resetting responses in adult rodents. However, circadian rhythms change throughout life and it is not yet known whether ethanol has similar effects on circadian regulation during adolescence. Methods General circadian locomotor activity was monitored in male C57BL6/J mice beginning in adolescence (P27) or adulthood (P61) in a 12 h light, 12 h dark photocycle for ~2 weeks to establish baseline circadian activity measures. On the day of the experiment, mice received an acute injection of ethanol (1.5 g/kg, i.p.) or equal volume saline 15 min prior to a 30-min light pulse at Zeitgeber Time 14 (2 h into the dark phase), then were released into constant darkness (DD) for ~2 weeks to assess phase-resetting responses. Control mice of each age group received injections but no light pulse prior to DD. Results While adults showed the expected decrease in photic phase-delays induced by acute ethanol, this effect was absent in adolescent mice. Adolescents also showed baseline differences in circadian rhythmicity compared to adults, including advanced photocycle entrainment, larger photic phase-delays, a shorter free-running (endogenous) circadian period, and greater circadian rhythm amplitude. Conclusions Collectively, our results indicate that adolescent mice are less sensitive to the effect of ethanol on circadian photic phase-resetting and that their daily activity rhythms are markedly different than those of adults. PMID:27997028

Lepidium meyenii (Maca) increases litter size in normal adult female mice

PubMed Central

Ruiz-Luna, Ana C; Salazar, Stephanie; Aspajo, Norma J; Rubio, Julio; Gasco, Manuel; Gonzales, Gustavo F

2005-01-01

Background Lepidium meyenii, known as Maca, grows exclusively in the Peruvian Andes over 4000 m altitude. It has been used traditionally to increase fertility. Previous scientific studies have demonstrated that Maca increases spermatogenesis and epididymal sperm count. The present study was aimed to investigate the effects of Maca on several fertility parameters of female mice at reproductive age. Methods Adult female Balb/C mice were divided at random into three main groups: i) Reproductive indexes group, ii) Implantation sites group and iii) Assessment of uterine weight in ovariectomized mice. Animals received an aqueous extract of lyophilized Yellow Maca (1 g/Kg BW) or vehicle orally as treatment. In the fertility indexes study, animals received the treatment before, during and after gestation. The fertility index, gestation index, post-natal viability index, weaning viability index and sex ratio were calculated. Sexual maturation was evaluated in the female pups by the vaginal opening (VO) day. In the implantation study, females were checked for implantation sites at gestation day 7 and the embryos were counted. In ovariectomized mice, the uterine weight was recorded at the end of treatment. Results Implantation sites were similar in mice treated with Maca and in controls. All reproductive indexes were similar in both groups of treatment. The number of pups per dam at birth and at postnatal day 4 was significantly higher in the group treated with Maca. VO day occurred earlier as litter size was smaller. Maca did not affect VO day. In ovariectomized mice, the treatment with Maca increased significantly the uterine weights in comparison to their respective control group. Conclusion Administration of aqueous extract of Yellow Maca to adult female mice increases the litter size. Moreover, this treatment increases the uterine weight in ovariectomized animals. Our study confirms for the first time some of the traditional uses of Maca to enhance female fertility. PMID

Lepidium meyenii (Maca) increases litter size in normal adult female mice.

PubMed

Ruiz-Luna, Ana C; Salazar, Stephanie; Aspajo, Norma J; Rubio, Julio; Gasco, Manuel; Gonzales, Gustavo F

2005-05-03

Lepidium meyenii, known as Maca, grows exclusively in the Peruvian Andes over 4000 m altitude. It has been used traditionally to increase fertility. Previous scientific studies have demonstrated that Maca increases spermatogenesis and epididymal sperm count. The present study was aimed to investigate the effects of Maca on several fertility parameters of female mice at reproductive age. Adult female Balb/C mice were divided at random into three main groups: i) Reproductive indexes group, ii) Implantation sites group and iii) Assessment of uterine weight in ovariectomized mice. Animals received an aqueous extract of lyophilized Yellow Maca (1 g/Kg BW) or vehicle orally as treatment. In the fertility indexes study, animals received the treatment before, during and after gestation. The fertility index, gestation index, post-natal viability index, weaning viability index and sex ratio were calculated. Sexual maturation was evaluated in the female pups by the vaginal opening (VO) day. In the implantation study, females were checked for implantation sites at gestation day 7 and the embryos were counted. In ovariectomized mice, the uterine weight was recorded at the end of treatment. Implantation sites were similar in mice treated with Maca and in controls. All reproductive indexes were similar in both groups of treatment. The number of pups per dam at birth and at postnatal day 4 was significantly higher in the group treated with Maca. VO day occurred earlier as litter size was smaller. Maca did not affect VO day. In ovariectomized mice, the treatment with Maca increased significantly the uterine weights in comparison to their respective control group. Administration of aqueous extract of Yellow Maca to adult female mice increases the litter size. Moreover, this treatment increases the uterine weight in ovariectomized animals. Our study confirms for the first time some of the traditional uses of Maca to enhance female fertility.

Adolescent C57BL/6J mice show elevated alcohol intake, but reduced taste aversion, as compared to adult mice: a potential behavioral mechanism for binge drinking.

PubMed

Holstein, Sarah E; Spanos, Marina; Hodge, Clyde W

2011-10-01

Binge alcohol drinking during adolescence is a serious health problem that may increase future risk of an alcohol use disorder. Although there are several different procedures by which to preclinically model binge-like alcohol intake, limited-access procedures offer the advantage of achieving high voluntary alcohol intake and pharmacologically relevant blood alcohol concentrations (BACs). Therefore, in the current study, developmental differences in binge-like alcohol drinking using a limited-access cycling procedure were examined. In addition, as alcohol drinking has been negatively correlated with sensitivity to the aversive properties of alcohol, we examined developmental differences in sensitivity to an alcohol-induced conditioned taste aversion (CTA). Binge-like alcohol consumption was investigated in adolescent (4 weeks) and adult (10 weeks) male C57BL/6J mice for 2 to 4 h/d for 16 days. Developmental differences in sensitivity to an alcohol-induced CTA were examined in adolescent and adult mice, with saline or alcohol (3 or 4 g/kg) repeatedly paired with the intake of a novel tastant (NaCl). Adolescent mice showed a significant increase in alcohol intake as compared to adults, with adolescents achieving higher BACs and increasing alcohol consumption over successive cycles of the binge procedure. Conversely, adolescent mice exhibited a dose-dependent reduction in sensitivity to the aversive properties of alcohol, as compared to adult mice, with adolescent mice failing to develop a CTA to 3 g/kg alcohol. Finally, extinction of an alcohol CTA was observed following conditioning with a higher dose of alcohol in adolescent, versus adult, mice. These results indicate that adolescent mice consume more alcohol, per kilogram body weight, than adults in a binge-like model of alcohol drinking and demonstrate a blunted sensitivity to the conditioned aversive effects of alcohol. Overall, this supports a behavioral framework by which heightened binge alcohol intake during

Adolescent C57BL/6J mice show elevated alcohol intake, but reduced taste aversion, as compared to adult mice: a potential behavioral mechanism for binge drinking

PubMed Central

Holstein, Sarah E.; Spanos, Marina; Hodge, Clyde W.

2011-01-01

Background Binge alcohol drinking during adolescence is a serious health problem which may increase future risk of an alcohol use disorder. Although there are several different procedures by which to preclinically model binge-like alcohol intake, limited-access procedures offer the advantage of achieving high voluntary alcohol intake and pharmacologically relevant blood alcohol concentrations (BACs). Therefore, in the current study, developmental differences in binge-like alcohol drinking using a limited-access cycling procedure were examined. In addition, as alcohol drinking has been negatively correlated with sensitivity to the aversive properties of alcohol, we examined developmental differences in sensitivity to an alcohol-induced conditioned taste aversion (CTA). Methods Binge-like alcohol consumption was investigated in adolescent (4 wk) and adult (10 wk) male C57BL/6J mice for 2-4 h/day for 16 d. Developmental differences in sensitivity to an alcohol-induced CTA were examined in adolescent and adult mice, with saline or alcohol (3 or 4 g/kg) repeatedly paired with intake of a novel tastant (NaCl). Results Adolescent mice showed a significant increase in alcohol intake as compared to adults, with adolescents achieving higher BACs and increasing alcohol consumption over successive cycles of the binge procedure. Conversely, adolescent mice exhibited a dose-dependent reduction in sensitivity to the aversive properties of alcohol, as compared to adult mice, with adolescent mice failing to develop a CTA to 3 g/kg alcohol. Finally, extinction of an alcohol CTA was observed following conditioning with a higher dose of alcohol in adolescent, versus adult, mice. Conclusions These results indicate that adolescent mice consume more alcohol, per kg body weight, than adults in a binge-like model of alcohol drinking, and demonstrate a blunted sensitivity to the conditioned aversive effects of alcohol. Overall, this supports a behavioral framework by which heightened binge

The clock gene Period1 regulates innate routine behaviour in mice

PubMed Central

Bechstein, Philipp; Rehbach, Nils-Jörn; Yuhasingham, Gowzekan; Schürmann, Christoph; Göpfert, Melanie; Kössl, Manfred; Maronde, Erik

2014-01-01

Laboratory mice are well capable of performing innate routine behaviour programmes necessary for courtship, nest-building and exploratory activities although housed for decades in animal facilities. We found that in mice inactivation of the clock gene Period1 profoundly changes innate routine behaviour programmes like those necessary for courtship, nest building, exploration and learning. These results in wild-type and Period1 mutant mice, together with earlier findings on courtship behaviour in wild-type and period-mutant Drosophila melanogaster, suggest a conserved role of Period-genes on innate routine behaviour. Additionally, both per-mutant flies and Period1-mutant mice display spatial learning and memory deficits. The profound influence of Period1 on routine behaviour programmes in mice, including female partner choice, may be independent of its function as a circadian clock gene, since Period1-deficient mice display normal circadian behaviour. PMID:24598427

Long-lasting Effects of Minocycline on Behavior in Young but not Adult Fragile X Mice

PubMed Central

Dansie, Lorraine E.; Phommahaxay, Kelly; Okusanya, Ayodeji G.; Uwadia, Jessica; Huang, Mike; Rotschafer, Sarah E.; Razak, Khaleel A.; Ethell, Douglas W.; Ethell, Iryna M.

2013-01-01

Fragile X Syndrome (FXS) is the most common single-gene inherited form of intellectual disability with behaviors characteristic of autism. People with FXS display childhood seizures, hyperactivity, anxiety, developmental delay, attention deficits, and visual-spatial memory impairment, as well as a propensity for obsessive-compulsive disorder (OCD). Several of these aberrant behaviors and FXS-associated synaptic irregularities also occur in “fragile X mental retardation gene” knock-out (Fmr1 KO) mice. We previously reported that minocycline promotes the maturation of dendritic spines - postsynaptic sites for excitatory synapses - in the developing hippocampus of Fmr1 KO mice, which may underlie the beneficial effects of minocycline on anxiolytic behavior in young Fmr1 KO mice. In this study, we compared the effectiveness of minocycline treatment in young and adult Fmr1 KO mice, and determined the dependence of behavioral improvements on short-term versus long-term minocycline administration. We found that 4 and 8 week long treatments significantly reduced locomotor activity in both young and adult Fmr1 KO mice. Some behavioral improvements persisted in young mice post-treatment, but in adults the beneficial effects were lost soon after minocycline treatment was stopped. We also show, for the first time, that minocycline treatment partially attenuates the number and severity of audiogenic seizures in Fmr1 KO mice. This report provides further evidence that minocycline treatment has immediate and long-lasting benefits on FXS-associated behaviors in the Fmr1 KO mouse model. PMID:23660195

Monocular Deprivation in Adult Mice Alters Visual Acuity and Single-Unit Activity

ERIC Educational Resources Information Center

Evans, Scott; Lickey, Marvin E.; Pham, Tony A.; Fischer, Quentin S.; Graves, Aundrea

2007-01-01

It has been discovered recently that monocular deprivation in young adult mice induces ocular dominance plasticity (ODP). This contradicts the traditional belief that ODP is restricted to a juvenile critical period. However, questions remain. ODP of young adults has been observed only using methods that are indirectly related to vision, and the…

Postnatal Loss of Hap1 Reduces Hippocampal Neurogenesis and Causes Adult Depressive-Like Behavior in Mice

PubMed Central

Xiang, Jianxing; Yan, Sen; Li, Shi-Hua; Li, Xiao-Jiang

2015-01-01

Depression is a serious mental disorder that affects a person’s mood, thoughts, behavior, physical health, and life in general. Despite our continuous efforts to understand the disease, the etiology of depressive behavior remains perplexing. Recently, aberrant early life or postnatal neurogenesis has been linked to adult depressive behavior; however, genetic evidence for this is still lacking. Here we genetically depleted the expression of huntingtin-associated protein 1 (Hap1) in mice at various ages or in selective brain regions. Depletion of Hap1 in the early postnatal period, but not later life, led to a depressive-like phenotype when the mice reached adulthood. Deletion of Hap1 in adult mice rendered the mice more susceptible to stress-induced depressive-like behavior. Furthermore, early Hap1 depletion impaired postnatal neurogenesis in the dentate gyrus (DG) of the hippocampus and reduced the level of c-kit, a protein expressed in neuroproliferative zones of the rodent brain and that is stabilized by Hap1. Importantly, stereotaxically injected adeno-associated virus (AAV) that directs the expression of c-kit in the hippocampus promoted postnatal hippocampal neurogenesis and ameliorated the depressive-like phenotype in conditional Hap1 KO mice, indicating a link between postnatal-born hippocampal neurons and adult depression. Our results demonstrate critical roles for Hap1 and c-kit in postnatal neurogenesis and adult depressive behavior, and also suggest that genetic variations affecting postnatal neurogenesis may lead to adult depression. PMID:25875952

Postnatal loss of hap1 reduces hippocampal neurogenesis and causes adult depressive-like behavior in mice.

PubMed

Xiang, Jianxing; Yan, Sen; Li, Shi-Hua; Li, Xiao-Jiang

2015-04-01

Depression is a serious mental disorder that affects a person's mood, thoughts, behavior, physical health, and life in general. Despite our continuous efforts to understand the disease, the etiology of depressive behavior remains perplexing. Recently, aberrant early life or postnatal neurogenesis has been linked to adult depressive behavior; however, genetic evidence for this is still lacking. Here we genetically depleted the expression of huntingtin-associated protein 1 (Hap1) in mice at various ages or in selective brain regions. Depletion of Hap1 in the early postnatal period, but not later life, led to a depressive-like phenotype when the mice reached adulthood. Deletion of Hap1 in adult mice rendered the mice more susceptible to stress-induced depressive-like behavior. Furthermore, early Hap1 depletion impaired postnatal neurogenesis in the dentate gyrus (DG) of the hippocampus and reduced the level of c-kit, a protein expressed in neuroproliferative zones of the rodent brain and that is stabilized by Hap1. Importantly, stereotaxically injected adeno-associated virus (AAV) that directs the expression of c-kit in the hippocampus promoted postnatal hippocampal neurogenesis and ameliorated the depressive-like phenotype in conditional Hap1 KO mice, indicating a link between postnatal-born hippocampal neurons and adult depression. Our results demonstrate critical roles for Hap1 and c-kit in postnatal neurogenesis and adult depressive behavior, and also suggest that genetic variations affecting postnatal neurogenesis may lead to adult depression.

The temperature-sensitive mutants of Toxoplasma gondii and ocular toxoplasmosis.

PubMed

Lu, Fangli; Huang, Shiguang; Kasper, Lloyd H

2009-01-22

The risk of blindness caused by ocular toxoplasmosis supports efforts to improve our understanding for control of this disease. In this study, the involvement of CD8(+), CD4(+), B cell, and IL-10 gene in the immune response of primary ocular infection with the temperature-sensitive mutant (ts-4) of the RH Toxoplasma gondii strain, and in the protective immunity of ocular ts-4 vaccination and challenge with RH strain was investigated in murine models utilizing inbred C57BL/6 mice-deficient in CD4(+), CD8(+), B cells (microMT), or IL-10 gene. Compared to naive mice, all WT and mutant mice had different degree of ocular pathological changes after ts-4 ocular infection, in which both CD8 KO and IL-10 KO mice showed the most severe ocular lesions. Immunized by ts-4 intracameral (i.c.) inoculation, all mutant mice had partially decreased vaccine-induced resistance associated with increased ocular parasite burdens after RH strain challenge. A significant increase of the percentages of B cells and CD8(+) T cells in the draining lymph nodes were observed in WT and IL-10 KO mice after either infection or challenge. The levels of specific anti-toxoplasma IgG in both eye fluid and serum from all the mice were significantly increased after ts-4 i.c. immunization, except microMT mice. These results suggest that the avirulent ts-4 of T. gondii inoculated intracamerally can induce both ocular pathology and ocular protective immunity; CD4(+), CD8(+), B cell, and IL-10 gene are all necessary to the vaccine-induced resistance to ocular challenge by virulent RH strain, in which CD8(+) T cells are the most important component.

Roles of p53 and p27 Kip1 in the regulation of neurogenesis in the murine adult subventricular zone

PubMed Central

Gil-Perotin, Sara; Haines, Jeffery D.; Kaur, Jasbir; Marin-Husstege, Mireya; Spinetta, Michael J.; Kim, Kwi-Hye; Duran-Moreno, Maria; Schallert, Timothy; Zindy, Frederique; Roussel, Martine F.; Garcia-Verdugo, Jose M.; Casaccia, Patrizia

2011-01-01

The tumor suppressor protein p53 (Trp53) and the cell cycle inhibitor p27 Kip1 (Cdknb1) have both been implicated in regulating proliferation of adult subventricular zone (aSVZ) cells. We previously reported that genetic ablation of Trp53 (Trp53 −/−) or Cdknb1 (p27 Kip1−/−) increased proliferation of cells in the aSVZ, but differentially affected the number of adult born neuroblasts. We therefore hypothesized that these molecules might play non-redundant roles. To test this hypothesis we generated mice lacking both genes (Trp53 −/−;p27 Kip1−/−) and analysed the consequences on aSVZ cells and adult neuroblasts. Proliferation and self-renewal of cultured aSVZ cells were increased in the double mutants compared with control, but the mice did not develop spontaneous brain tumors. In contrast, the number of adult-born neuroblasts in the double mutants was similar to wild-type animals and suggested a complementation of the p27 Kip1−/− phenotype due to loss of Trp53. Cellular differences detected in the aSVZ correlated with cellular changes in the olfactory bulb and behavioral data on novel odor recognition. The exploration time for new odors was reduced in p27 Kip1−/− mice, increased in Trp53 −/− mice and normalized in the double Trp53−/−;p27 Kip1−/− mutants. At the molecular level, Trp53 −/− aSVZ cells were characterized by higher levels of NeuroD and Math3 and by the ability to generate neurons more readily. In contrast, p27 Kip1−/− cells generated fewer neurons, due to enhanced proteasomal degradation of pro-neural transcription factors. Together, these results suggest that p27 Kip1 and p53 function non-redundantly to modulate proliferation and self-renewal of aSVZ cells and antagonistically in regulating adult neurogenesis. PMID:21899604

Rational Design of a Live Attenuated Dengue Vaccine: 2′-O-Methyltransferase Mutants Are Highly Attenuated and Immunogenic in Mice and Macaques

PubMed Central

Chang, David C.; Zhang, Bo; Balakrishnan, Thavamalar; Toh, Ying-Xiu; Jiang, Tao; Li, Shi-Hua; Deng, Yong-Qiang; Ellis, Brett R.; Ellis, Esther M.; Poidinger, Michael; Zolezzi, Francesca; Qin, Cheng-Feng; Shi, Pei-Yong; Fink, Katja

2013-01-01

Dengue virus is transmitted by Aedes mosquitoes and infects at least 100 million people every year. Progressive urbanization in Asia and South-Central America and the geographic expansion of Aedes mosquito habitats have accelerated the global spread of dengue, resulting in a continuously increasing number of cases. A cost-effective, safe vaccine conferring protection with ideally a single injection could stop dengue transmission. Current vaccine candidates require several booster injections or do not provide protection against all four serotypes. Here we demonstrate that dengue virus mutants lacking 2′-O-methyltransferase activity are highly sensitive to type I IFN inhibition. The mutant viruses are attenuated in mice and rhesus monkeys and elicit a strong adaptive immune response. Monkeys immunized with a single dose of 2′-O-methyltransferase mutant virus showed 100% sero-conversion even when a dose as low as 1,000 plaque forming units was administrated. Animals were fully protected against a homologous challenge. Furthermore, mosquitoes feeding on blood containing the mutant virus were not infected, whereas those feeding on blood containing wild-type virus were infected and thus able to transmit it. These results show the potential of 2′-O-methyltransferase mutant virus as a safe, rationally designed dengue vaccine that restrains itself due to the increased susceptibility to the host's innate immune response. PMID:23935499

Nuclei pulposi formation from the embryonic notochord occurs normally in GDF-5-deficient mice.

PubMed

Maier, Jennifer A; Harfe, Brian D

2011-11-15

The transition of the mouse embryonic notochord into nuclei pulposi was determined ("fate mapped") in vivo in growth and differentiating factor-5 (GDF-5)-null mice using the Shhcre and R26R alleles. To determine whether abnormal nuclei pulposi formation from the embryonic notochord was responsible for defects present in adult nuclei pulposi of Gdf-5-null mice. The development, maintenance, and degeneration of the intervertebral disc are not understood. Previously, we demonstrated that all cells in the adult nucleus pulposus of normal mice are derived from the embryonic notochord. Gdf-5-null mice have been reported to contain intervertebral discs in which the nucleus pulposus is abnormal. It is currently unclear if disc defects in Gdf-5-null mice arise during the formation of nuclei pulposi from the notochord during embryogenesis or result from progressive postnatal degeneration of nuclei pulposi. Gdf-5 messenger RNA expression was examined in the discs of wild-type embryos by RNA in situ hybridization to determine when and where this gene was expressed. To examine nucleus pulposus formation in Gdf-5-null mice, intervertebral discs in which embryonic notochord cells were marked were analyzed in newborn and 24-week-old mice. Our Gdf-5 messenger RNA in situ experiments determined that this gene is localized to the annulus fibrosus and not the nucleus pulposus in mouse embryos. Notochord fate-mapping experiments revealed that notochord cells in Gdf-5-null mice correctly form nuclei pulposi. Our data suggest that the defects reported in the nucleus pulposus of adult Gdf-5-null mice do not result from abnormal patterning of the embryonic notochord. The use of mouse alleles to mark cells that produce all cell types that reside in the adult nucleus pulposus will allow for a detailed examination of disc formation in other mouse mutants that have been reported to contain disc defects.

Mutant Ataxin-1 Inhibits Neural Progenitor Cell Proliferation in SCA1

PubMed Central

Cvetanovic, Marija; Hu, Yuan-Shih; Opal, Puneet

2017-01-01

Spinocerebellar ataxia type 1 (SCA1) is a dominantly inherited neurodegenerative disease caused by the expansion of a polyglutamine (Q) repeat tract in the protein ataxin-1 (ATXN1). Beginning as a cerebellar ataxic disorder, SCA1 progresses to involve the cerebral cortex, hippocampus, and brainstem. Using SCA1 knock-in mice that mirror the complexity of the human disease, we report a significant decrease in the capacity of adult neuronal progenitor cells (NPCs) to proliferate. Remarkably, a decrease in NPCs proliferation can be observed in vitro, outside the degenerative milieu of surrounding neurons or glia, demonstrating that mutant ATXN1 acting cell autonomously within progenitor cells interferes with their ability to proliferate. Our findings suggest that compromised adult neurogenesis contributes to the progressive pathology of the disease particularly in areas such as the hippocampus and cerebral cortex where stem cells provide neurotropic factors and participate in adult neurogenesis. These findings not only shed light on the biology of the disease but also have therapeutic implications in any future stem cell- based clinical trials. PMID:27306906

Mutant Ataxin-1 Inhibits Neural Progenitor Cell Proliferation in SCA1.

PubMed

Cvetanovic, Marija; Hu, Yuan-Shih; Opal, Puneet

2017-04-01

Spinocerebellar ataxia type 1 (SCA1) is a dominantly inherited neurodegenerative disease caused by the expansion of a polyglutamine (Q) repeat tract in the protein ataxin-1 (ATXN1). Beginning as a cerebellar ataxic disorder, SCA1 progresses to involve the cerebral cortex, hippocampus, and brainstem. Using SCA1 knock-in mice that mirror the complexity of the human disease, we report a significant decrease in the capacity of adult neuronal progenitor cells (NPCs) to proliferate. Remarkably, a decrease in NPCs proliferation can be observed in vitro, outside the degenerative milieu of surrounding neurons or glia, demonstrating that mutant ATXN1 acting cell autonomously within progenitor cells interferes with their ability to proliferate. Our findings suggest that compromised adult neurogenesis contributes to the progressive pathology of the disease particularly in areas such as the hippocampus and cerebral cortex where stem cells provide neurotropic factors and participate in adult neurogenesis. These findings not only shed light on the biology of the disease but also have therapeutic implications in any future stem cell-based clinical trials.

Proteostasis and ageing: insights from long-lived mutant mice.

PubMed

Sands, William A; Page, Melissa M; Selman, Colin

2017-10-15

The global increase in life expectancy is creating significant medical, social and economic challenges to current and future generations. Consequently, there is a need to identify the fundamental mechanisms underlying the ageing process. This knowledge should help develop realistic interventions capable of combatting age-related disease, and thus improving late-life health and vitality. While several mechanisms have been proposed as conserved lifespan determinants, the loss of proteostasis - where proteostasis is defined here as the maintenance of the proteome - appears highly relevant to both ageing and disease. Several studies have shown that multiple proteostatic mechanisms, including the endoplasmic reticulum (ER)-induced unfolded protein response (UPR), the ubiquitin-proteasome system (UPS) and autophagy, appear indispensable for longevity in many long-lived invertebrate mutants. Similarly, interspecific comparisons suggest that proteostasis may be an important lifespan determinant in vertebrates. Over the last 20 years a number of long-lived mouse mutants have been described, many of which carry single-gene mutations within the growth-hormone, insulin/IGF-1 or mTOR signalling pathways. However, we still do not know how these mutations act mechanistically to increase lifespan and healthspan, and accordingly whether mechanistic commonality occurs between different mutants. Recent evidence supports the premise that the successful maintenance of the proteome during ageing may be linked to the increased lifespan and healthspan of long-lived mouse mutants. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Adolescent mice are less sensitive to the effects of acute nicotine on context pre-exposure than adults.

PubMed

Kutlu, Munir Gunes; Braak, David C; Tumolo, Jessica M; Gould, Thomas J

2016-07-01

Adolescence is a critical developmental period associated with both increased vulnerability to substance abuse and maturation of certain brain regions important for learning and memory such as the hippocampus. In this study, we employed a hippocampus-dependent learning context pre-exposure facilitation effect (CPFE) paradigm in order to test the effects of acute nicotine on contextual processing during adolescence (post-natal day (PND) 38) and adulthood (PND 53). In Experiment 1, adolescent or adult C57BL6/J mice received either saline or one of three nicotine doses (0.09, 0.18, and 0.36mg/kg) prior to contextual pre-exposure and testing. Our results demonstrated that both adolescent and adult mice showed CPFE in the saline groups. However, adolescent mice only showed acute nicotine enhancement of CPFE with the highest nicotine dose whereas adult mice showed the enhancing effects of acute nicotine with all three doses. In Experiment 2, to determine if the lack of nicotine's effects on CPFE shown by adolescent mice is specific to the age when they are tested, mice were either given contextual pre-exposure during adolescence or adulthood and received immediate shock and testing during adulthood after a 15day delay. We found that both adolescent and adult mice showed CPFE in the saline groups when tested during adulthood. However, like Experiment 1, mice that received contextual pre-exposure during adolescence did not show acute nicotine enhancement except at the highest dose (0.36mg/kg) whereas both low (0.09mg/kg) and high (0.36mg/kg) doses enhanced CPFE in adult mice. Finally, we showed that the enhanced freezing response found with 0.36mg/kg nicotine in the 15-day experiment may be a result of decreased locomotor activity as mice that received this dose of nicotine traveled shorter distances in an open field paradigm. Overall, our results indicate that while adolescent mice showed normal contextual processing when tested both during adolescence and adulthood, they

Adeno-Associated Viral Vector Serotype DJ-Mediated Overexpression of N171-82Q-Mutant Huntingtin in the Striatum of Juvenile Mice Is a New Model for Huntington's Disease.

PubMed

Jang, Minhee; Lee, Seung Eun; Cho, Ik-Hyun

2018-01-01

Huntington's disease (HD) is an autosomal-dominant inherited neurodegenerative disorder characterized by motor, psychiatric and cognitive symptoms. HD is caused by an expansion of CAG repeats in the huntingtin ( HTT ) gene in various areas of the brain including striatum. There are few suitable animal models to study the pathogenesis of HD and validate therapeutic strategies. Recombinant adeno-associated viral (AAV) vectors successfully transfer foreign genes to the brain of adult mammalians. In this article, we report a novel mouse model of HD generated by bilateral intrastriatal injection of AAV vector serotype DJ (AAV-DJ) containing N171-82Q mutant HTT (82Q) and N171-18Q wild type HTT (18Q; sham). The AAV-DJ-82Q model displayed motor dysfunctions in pole and rotarod tests beginning 4 weeks after viral infection in juvenile mice (8 weeks after birth). They showed behaviors reflecting neurodegeneration. They also showed increased apoptosis, robust glial activation and upregulated representative inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6), mediators (cyclooxygenase-2 and inducible nitric oxide synthase) and signaling pathways (nuclear factor kappa B and signal transducer and activator of transcription 3 (STAT3)) in the striatum at 10 weeks after viral infection (14 weeks after birth) via successful transfection of mutant HTT into neurons, microglia, and astrocytes in the striatum. However, little evidence of any of these events was found in mice infected with the AAV-DJ-18Q expressing construct. Intrastriatal injection of AAV-DJ-82Q might be useful as a novel in vivo model to investigate the biology of truncated N-terminal fragment (N171) in the striatum and to explore the efficacy of therapeutic strategies for HD.

Pattern of retinal morphological and functional decay in a light-inducible, rhodopsin mutant mouse.

PubMed

Gargini, Claudia; Novelli, Elena; Piano, Ilaria; Biagioni, Martina; Strettoi, Enrica

2017-07-18

Hallmarks of Retinitis Pigmentosa (RP), a family of genetic diseases, are a typical rod-cone-degeneration with initial night blindness and loss of peripheral vision, followed by decreased daylight sight and progressive visual acuity loss up to legal blindness. Great heterogeneity in nature and function of mutated genes, variety of mutations for each of them, variability in phenotypic appearance and transmission modality contribute to make RP a still incurable disease. Translational research relies on appropriate animal models mimicking the genetic and phenotypic diversity of the human pathology. Here, we provide a systematic, morphological and functional analysis of Rho Tvrm4 /Rho + rhodopsin mutant mice, originally described in 2010 and portraying several features of common forms of autosomal dominant RP caused by gain-of-function mutations. These mice undergo photoreceptor degeneration only when exposed briefly to strong, white light and allow controlled timing of induction of rod and cone death, which therefore can be elicited in adult animals, as observed in human RP. The option to control severity and retinal extent of the phenotype by regulating intensity and duration of the inducing light opens possibilities to exploit this model for multiple experimental purposes. Altogether, the unique features of this mutant make it an excellent resource for retinal degeneration research.

Differential expression of glutamate transporters EAAT1 and EAAT2 in mice deficient for PACAP-type I receptor.

PubMed

Zink, M; Schmitt, A; Henn, F A; Gass, P

2004-12-01

Pituitary adenylate cyclase-activating polypeptide (PACAP) modulates glutamatergic neurotransmission and induces the expression of glutamate transporters EAAT1 and EAAT2 in newborn mouse astroglial cell cultures. Since nanomolar concentrations of PACAP exert this effect, signal transduction via the high affinity PACAP-type I-receptor PAC1 was assumed. To test this hypothesis and to assess the importance of PAC1-signalling in vivo, we analyzed glutamate transporter expression in mice with a PAC1 knockout. EAAT1 and EAAT2 expression was investigated in the hippocampus and the cerebral cortex of PAC1 mutant mice and wildtype littermates by semiquantitative in-situ-hybridization. PAC1-knockout mice show a subtle but significant reduction of EAAT1 expression in the dentate gyrus. In contrast, reduced expression levels of EAAT1 in the cerebral cortex did not reach statistical significance and EAAT2 expression was unchanged in CA3 and cerebral cortex of PAC1 mutant mice. Our data confirm the previously reported in-vitro-regulation of EAAT1 in the adult nervous system in vivo. EAAT2 expression, however, is unchanged in PAC1 knockout mice, most likely due to counterbalancing factors.

Adolescent silymarin treatment increases anxiety-like behaviors in adult mice.

PubMed

Kosari-Nasab, Morteza; Rabiei, Afshin; Doosti, Mohammad-Hossein; Salari, Ali-Akbar

2014-08-01

Adolescence is one of the most important periods of brain development in mammals. There is increasing evidence that some medicines during this period can affect brain and behavioral functions in adulthood. Silymarin (SM), a mixture of flavonolignans extracted from the milk thistle Silybum marianum, is known as a hepatoprotective, anti-inflammatory, and neuroprotective drug. Although researchers have extensively studied the effects of SM during adulthood, to date there is no information on the effects of this drug during the stages of brain development on behavioral functions in adulthood. In the current study, we investigated the effects of adolescent SM treatment on body weight and anxiety-like behaviors in adult male and female mice. Adolescent NMRI mice (postnatal day 30-50) were treated orally with water or SM (50 and 100 mg/kg). Animals were weighed during drug treatment and were then subjected to open field, elevated plus maze, and light-dark box tests from postnatal day 70. The results indicated that adolescent SM treatment increased anxiety-like behaviors in open field, elevated plus maze, and light-dark box in adult mice, while not altering body weight. Collectively, these findings suggest that adolescent SM treatment may have profound effects on the development of brain and behavior in adulthood.

Antisense reduction of tau in adult mice protects against seizures.

PubMed

DeVos, Sarah L; Goncharoff, Dustin K; Chen, Guo; Kebodeaux, Carey S; Yamada, Kaoru; Stewart, Floy R; Schuler, Dorothy R; Maloney, Susan E; Wozniak, David F; Rigo, Frank; Bennett, C Frank; Cirrito, John R; Holtzman, David M; Miller, Timothy M

2013-07-31

Tau, a microtubule-associated protein, is implicated in the pathogenesis of Alzheimer's Disease (AD) in regard to both neurofibrillary tangle formation and neuronal network hyperexcitability. The genetic ablation of tau substantially reduces hyperexcitability in AD mouse lines, induced seizure models, and genetic in vivo models of epilepsy. These data demonstrate that tau is an important regulator of network excitability. However, developmental compensation in the genetic tau knock-out line may account for the protective effect against seizures. To test the efficacy of a tau reducing therapy for disorders with a detrimental hyperexcitability profile in adult animals, we identified antisense oligonucleotides that selectively decrease endogenous tau expression throughout the entire mouse CNS--brain and spinal cord tissue, interstitial fluid, and CSF--while having no effect on baseline motor or cognitive behavior. In two chemically induced seizure models, mice with reduced tau protein had less severe seizures than control mice. Total tau protein levels and seizure severity were highly correlated, such that those mice with the most severe seizures also had the highest levels of tau. Our results demonstrate that endogenous tau is integral for regulating neuronal hyperexcitability in adult animals and suggest that an antisense oligonucleotide reduction of tau could benefit those with epilepsy and perhaps other disorders associated with tau-mediated neuronal hyperexcitability.

Selenium status alters the immune response and expulsion of adult Heligmosomodies bakeri in mice

USDA-ARS?s Scientific Manuscript database

Heligmosomoides bakeri is a nematode with parasitic development exclusively in the small intestine of infected mice that induces a potent STAT6-dependent Th2 immune response. We previously demonstrated that host protective expulsion of adult H. bakeri was delayed in selenium (Se) deficient mice. ...

Proteoglycan 4: A Dynamic Regulator of Skeletogenesis and Parathyroid Hormone Skeletal Anabolism

PubMed Central

Novince, Chad M; Michalski, Megan N; Koh, Amy J; Sinder, Benjamin P; Entezami, Payam; Eber, Matthew R; Pettway, Glenda J; Rosol, Thomas J; Wronski, Thomas J; Kozloff, Ken M; McCauley, Laurie K

2014-01-01

Proteoglycan 4 (Prg4), known for its lubricating and protective actions in joints, is a strong candidate regulator of skeletal homeostasis and parathyroid hormone (PTH) anabolism. Prg4 is a PTH-responsive gene in bone and liver. Prg4 null mutant mice were used to investigate the impact of proteoglycan 4 on skeletal development, remodeling, and PTH anabolic actions. Young Prg4 mutant and wild-type mice were administered intermittent PTH(1–34) or vehicle daily from 4 to 21 days. Young Prg4 mutant mice had decreased growth plate hypertrophic zones, trabecular bone, and serum bone formation markers versus wild-type mice, but responded with a similar anabolic response to PTH. Adult Prg4 mutant and wild-type mice were administered intermittent PTH(1–34) or vehicle daily from 16 to 22 weeks. Adult Prg4 mutant mice had decreased trabecular and cortical bone, and blunted PTH-mediated increases in bone mass. Joint range of motion and animal mobility were lower in adult Prg4 mutant versus wild-type mice. Adult Prg4 mutant mice had decreased marrow and liver fibroblast growth factor 2 (FGF-2) mRNA and reduced serum FGF-2, which were normalized by PTH. A single dose of PTH decreased the PTH/PTHrP receptor (PPR), and increased Prg4 and FGF-2 to a similar extent in liver and bone. Proteoglycan 4 supports endochondral bone formation and the attainment of peak trabecular bone mass, and appears to support skeletal homeostasis indirectly by protecting joint function. Bone- and liver-derived FGF-2 likely regulate proteoglycan 4 actions supporting trabeculae formation. Blunted PTH anabolic responses in adult Prg4 mutant mice are associated with altered biomechanical impact secondary to joint failure. PMID:21932346

Inhibitory effect on natural killer activity of microphthalmia transcription factor encoded by the mutant mi allele of mice.

PubMed

Ito, A; Kataoka, T R; Kim, D K; Koma , Y; Lee, Y M; Kitamura, Y

2001-04-01

The mouse mi locus encodes a basic-helix-loop-helix-leucine zipper-type transcription factor, microphthalmia transcription factor (MITF). Mice of mi/mi genotype express a mutant form of MITF (mi-MITF), whereas mice of tg/tg genotype have a transgene in the 5' flanking region of the mi gene and do not express MITF. Although the mi/mi mouse is deficient in natural killer (NK) activity, it was found that the tg/tg mouse was normal in this respect. To know the cause, spleen cells of both genotypes were compared. Although the proportion of spleen cells expressing an NK cell marker, NK1.1, was comparable in both mice, the proportion of large granular lymphocytes decreased only in mi/mi mice. The difference between mi/mi and tg/tg mice was reproducible in the culture supplemented with interleukin-2. Moreover, the perforin gene expression was reduced in mi/mi-cultured spleen cells. Wild-type (+) MITF transactivated, but mi-MITF suppressed, the perforin gene promoter through the NF-P motif, a strong cis-acting element. However, neither +-MITF nor mi-MITF bound the NF-P motif. Instead, 2 nuclear factors that bound the NF-P motif were retained in the cytoplasm of mi/mi-cultured spleen cells. In addition, overexpression of mi-MITF resulted in cytoplasmic retention of the 2 NF-P motif-binding factors in cytotoxic T lymphocytes. The presence of mi-MITF rather than the absence of +-MITF appeared to lead to poor transactivation of the NF-P motif by intercepting NF-P motif-binding factors. This inhibitory effect of mi-MITF may cause the deficient cytotoxicity of NK cells in mi/mi mice. (Blood. 2001;97:2075-2083)

AGED DOMINANT NEGATIVE p38α MAPK MICE ARE RESISTANT TO AGE-DEPENDENT DECLINE IN ADULT-NEUROGENESIS AND CONTEXT DISCRIMINATION FEAR CONDITIONING

PubMed Central

Cortez, IbDanelo; Bulavin, Dmitry V.; Wu, Ping; McGrath, Erica L; Cunningham, Kathryn A; Wakamiya, Maki; Papaconstantinou, John; Dineley, Kelly T

2018-01-01

A major aspect of mammalian aging is the decline in functional competence of many self-renewing cell types, including adult-born neuronal precursors. Since age-related senescence of self-renewal occurs simultaneously with chronic up-regulation of the p38MAPKalpha (p38α) signaling pathway, we used the dominant negative mouse model for attenuated p38α activity (DN-p38αAF/+ ) in which Thr180 and Tyr182 are mutated (T→A/Y→F) to prevent phosphorylation activation (DN-p38αAF/+) and kinase activity. As a result, aged DN-p38αAF/+ mice are resistant to age-dependent decline in proliferation and regeneration of several peripheral tissue progenitors when compared to wild-type littermates. Aging is the major risk factor for non-inherited forms of Alzheimer’s disease (AD); environmental and genetic risk factors that accelerate the senescence phenotype are thought to contribute to an individual’s relative risk. In the present study, we evaluated aged DN-p38αAF/+ and wildtype littermates in a series of behavioral paradigms to test if p38α mutant mice exhibit altered baseline abnormalities in neurological reflexes, locomotion, anxiety-like behavior, and age-dependent cognitive decline. While aged DN-p38αAF/+ and wildtype littermates appear equal in all tested baseline neurological and behavioral parameters, DN-p38αAF/+ exhibit superior context discrimination fear conditioning. Context discrimination is a cognitive task that is supported by proliferation and differentiation of adult-born neurons in the dentate gyrus of the hippocampus. Consistent with enhanced context discrimination in aged DN-p38αAF/+, we discovered enhanced production of adult-born neurons in the dentate gyrus of DN-p38αAF/+ mice compared to wildtype littermates. Our findings support the notion that p38α inhibition has therapeutic utility in aging diseases that affect cognition, such as AD. PMID:27765672

Aged dominant negative p38α MAPK mice are resistant to age-dependent decline in adult-neurogenesis and context discrimination fear conditioning.

PubMed

Cortez, IbDanelo; Bulavin, Dmitry V; Wu, Ping; McGrath, Erica L; Cunningham, Kathryn A; Wakamiya, Maki; Papaconstantinou, John; Dineley, Kelly T

2017-03-30

A major aspect of mammalian aging is the decline in functional competence of many self-renewing cell types, including adult-born neuronal precursors. Since age-related senescence of self-renewal occurs simultaneously with chronic up-regulation of the p38MAPKalpha (p38α) signaling pathway, we used the dominant negative mouse model for attenuated p38α activity (DN-p38α AF/+ ) in which Thr180 and Tyr182 are mutated (T→A/Y→F) to prevent phosphorylation activation (DN-p38α AF/+ ) and kinase activity. As a result, aged DN-p38α AF/+ mice are resistant to age-dependent decline in proliferation and regeneration of several peripheral tissue progenitors when compared to wild-type littermates. Aging is the major risk factor for non-inherited forms of Alzheimer's disease (AD); environmental and genetic risk factors that accelerate the senescence phenotype are thought to contribute to an individual's relative risk. In the present study, we evaluated aged DN-p38α AF/+ and wildtype littermates in a series of behavioral paradigms to test if p38α mutant mice exhibit altered baseline abnormalities in neurological reflexes, locomotion, anxiety-like behavior, and age-dependent cognitive decline. While aged DN-p38α AF/+ and wildtype littermates appear equal in all tested baseline neurological and behavioral parameters, DN-p38α AF/+ exhibit superior context discrimination fear conditioning. Context discrimination is a cognitive task that is supported by proliferation and differentiation of adult-born neurons in the dentate gyrus of the hippocampus. Consistent with enhanced context discrimination in aged DN-p38α AF/+ , we discovered enhanced production of adult-born neurons in the dentate gyrus of DN-p38α AF/+ mice compared to wildtype littermates. Our findings support the notion that p38α inhibition has therapeutic utility in aging diseases that affect cognition, such as AD. Copyright © 2016 Elsevier B.V. All rights reserved.

Alternating Hemiplegia of Childhood-Related Neural and Behavioural Phenotypes in Na+,K+-ATPase α3 Missense Mutant Mice

PubMed Central

Kirshenbaum, Greer S.; Dawson, Neil; Mullins, Jonathan G. L.; Johnston, Tom H.; Drinkhill, Mark J.; Edwards, Ian J.; Fox, Susan H.; Pratt, Judith A.; Brotchie, Jonathan M.; Roder, John C.; Clapcote, Steven J.

2013-01-01

Missense mutations in ATP1A3 encoding Na+,K+-ATPase α3 have been identified as the primary cause of alternating hemiplegia of childhood (AHC), a motor disorder with onset typically before the age of 6 months. Affected children tend to be of short stature and can also have epilepsy, ataxia and learning disability. The Na+,K+-ATPase has a well-known role in maintaining electrochemical gradients across cell membranes, but our understanding of how the mutations cause AHC is limited. Myshkin mutant mice carry an amino acid change (I810N) that affects the same position in Na+,K+-ATPase α3 as I810S found in AHC. Using molecular modelling, we show that the Myshkin and AHC mutations display similarly severe structural impacts on Na+,K+-ATPase α3, including upon the K+ pore and predicted K+ binding sites. Behavioural analysis of Myshkin mice revealed phenotypic abnormalities similar to symptoms of AHC, including motor dysfunction and cognitive impairment. 2-DG imaging of Myshkin mice identified compromised thalamocortical functioning that includes a deficit in frontal cortex functioning (hypofrontality), directly mirroring that reported in AHC, along with reduced thalamocortical functional connectivity. Our results thus provide validation for missense mutations in Na+,K+-ATPase α3 as a cause of AHC, and highlight Myshkin mice as a starting point for the exploration of disease mechanisms and novel treatments in AHC. PMID:23527305

Vestibular Evoked Myogenic Potentials in Normal Mice and Phex Mice With Spontaneous Endolymphatic Hydrops

PubMed Central

Sheykholeslami, Kianoush; Megerian, Cliff A.; Zheng, Qing Y.

2010-01-01

Objective and Background Vestibular evoked myogenic potentials (VEMPs) have been recorded from the neck musculature and the cervical spinal cord in humans and a limited number of laboratory animals in response to loud sound. However, the mouse VEMP has yet to be described. Evaluation of the sacculocollic pathway via VEMPs in mice can set the stage for future evaluations of mutant mice that now play an important role in research regarding human auditory and vestibular dysfunction. Materials and Methods Sound-evoked potentials were recorded from the neck extensor muscles and the cervical spinal cord in normal adult mice and in circling PhexHyp-Duk/y mice with known vestibular abnormalities, including endolymphatic hydrops (ELH). Results Biphasic potentials were recorded from all normal animals. The mean threshold of the VEMP response in normal adult mice was 60 dB normal hearing level with a mean peak latency of 6.25 ± 0.46 and 7.95 ± 0.42 milliseconds for p1 and n1 peaks, respectively. At the maximum sound intensity used (100 dB normal hearing level), 4 of 5 Phex mice did not exhibit VEMP responses, and 1 showed an elevated threshold, but normal response, with regard to peak latency and amplitude. The histologic findings in all of these Phex mice were consistent with distended membranous labyrinth, displaced Reissner membrane, ganglion cell loss, and ELH. Conclusion This is the first report of VEMP recordings in mice and the first report of abnormal VEMPs in a mouse model with ELH. The characteristics of these potentials such as higher response threshold in comparison to auditory brainstem response, myogenic nature of the response, and latency correlation with the cervical recording (accessory nerve nucleus) were similar to those of VEMPs in humans, guinea pigs, cats, and rats, suggesting that the mouse may be used as an animal model in the study of VEMPs. The simplicity and reliability of these recordings make the VEMP a uniquely informative test for assessing

Adeno-Associated Viral Vector Serotype DJ-Mediated Overexpression of N171-82Q-Mutant Huntingtin in the Striatum of Juvenile Mice Is a New Model for Huntington’s Disease

PubMed Central

Jang, Minhee; Lee, Seung Eun; Cho, Ik-Hyun

2018-01-01

Huntington’s disease (HD) is an autosomal-dominant inherited neurodegenerative disorder characterized by motor, psychiatric and cognitive symptoms. HD is caused by an expansion of CAG repeats in the huntingtin (HTT) gene in various areas of the brain including striatum. There are few suitable animal models to study the pathogenesis of HD and validate therapeutic strategies. Recombinant adeno-associated viral (AAV) vectors successfully transfer foreign genes to the brain of adult mammalians. In this article, we report a novel mouse model of HD generated by bilateral intrastriatal injection of AAV vector serotype DJ (AAV-DJ) containing N171-82Q mutant HTT (82Q) and N171-18Q wild type HTT (18Q; sham). The AAV-DJ-82Q model displayed motor dysfunctions in pole and rotarod tests beginning 4 weeks after viral infection in juvenile mice (8 weeks after birth). They showed behaviors reflecting neurodegeneration. They also showed increased apoptosis, robust glial activation and upregulated representative inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6), mediators (cyclooxygenase-2 and inducible nitric oxide synthase) and signaling pathways (nuclear factor kappa B and signal transducer and activator of transcription 3 (STAT3)) in the striatum at 10 weeks after viral infection (14 weeks after birth) via successful transfection of mutant HTT into neurons, microglia, and astrocytes in the striatum. However, little evidence of any of these events was found in mice infected with the AAV-DJ-18Q expressing construct. Intrastriatal injection of AAV-DJ-82Q might be useful as a novel in vivo model to investigate the biology of truncated N-terminal fragment (N171) in the striatum and to explore the efficacy of therapeutic strategies for HD. PMID:29946240

Effects of acute social stress on the conditioned place preference induced by MDMA in adolescent and adult mice.

PubMed

García-Pardo, Maria P; Rodríguez-Arias, Marta; Maldonado, Concepcion; Manzanedo, Carmen; Miñarro, Jose; Aguilar, Maria A

2014-09-01

Exposure to social defeat stress increases the rewarding effects of psychostimulants in animal models, but its effect on 3,4-methylenedioxymethylamphetamine (MDMA) reward has received little attention. In the present study, we evaluated the influence of social defeat on the rewarding effects of MDMA in adolescent [postnatal day (PND) 29-40] and adult (PND 50-61) male mice using the conditioned place preference paradigm. Experimental mice were exposed to social defeat in an agonistic encounter before each session of conditioning with 1.25 or 10 mg/kg of MDMA. The effects of social defeat on corticosterone levels and the motor or the anxiogenic effects of MDMA were also evaluated. Mice exposed to social defeat during adulthood did not show conditioned place preference after conditioning with either dose of MDMA. Conversely, social defeat did not affect the anxiogenic and motor effects of MDMA. Adult mice exposed to social defeat showed higher levels of corticosterone than their controls and adolescent mice. Social stress did not induce behavioural effects in adolescent mice. Our results show that stress induced by social defeat decreases the sensitivity of adult mice to the rewarding effects of MDMA.

A humanized version of Foxp2 does not affect ultrasonic vocalization in adult mice.

PubMed

Hammerschmidt, K; Schreiweis, C; Minge, C; Pääbo, S; Fischer, J; Enard, W

2015-11-01

The transcription factor FOXP2 has been linked to severe speech and language impairments in humans. An analysis of the evolution of the FOXP2 gene has identified two amino acid substitutions that became fixed after the split of the human and chimpanzee lineages. Studying the functional consequences of these two substitutions in the endogenous Foxp2 gene of mice showed alterations in dopamine levels, striatal synaptic plasticity, neuronal morphology and cortico-striatal-dependent learning. In addition, ultrasonic vocalizations (USVs) of pups had a significantly lower average pitch than control littermates. To which degree adult USVs would be affected in mice carrying the 'humanized' Foxp2 variant remained unclear. In this study, we analyzed USVs of 68 adult male mice uttered during repeated courtship encounters with different females. Mice carrying the Foxp2(hum/hum) allele did not differ significantly in the number of call elements, their element structure or in their element composition from control littermates. We conclude that neither the structure nor the usage of USVs in adult mice is affected by the two amino acid substitutions that occurred in FOXP2 during human evolution. The reported effect for pup vocalization thus appears to be transient. These results are in line with accumulating evidence that mouse USVs are hardly influenced by vocal learning. Hence, the function and evolution of genes that are necessary, but not sufficient for vocal learning in humans, must be either studied at a different phenotypic level in mice or in other organisms. © 2015 The Authors. Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.

Zfp488 promotes oligodendrocyte differentiation of neural progenitor cells in adult mice after demyelination

PubMed Central

Soundarapandian, Mangala M.; Selvaraj, Vimal; Lo, U-Ging; Golub, Mari S.; Feldman, Daniel H.; Pleasure, David E.; Deng, Wenbin

2011-01-01

Basic helix-loop-helix transcription factors Olig1 and Olig2 critically regulate oligodendrocyte development. Initially identified as a downstream effector of Olig1, an oligodendrocyte-specific zinc finger transcription repressor, Zfp488, cooperates with Olig2 function. Although Zfp488 is required for oligodendrocyte precursor formation and differentiation during embryonic development, its role in oligodendrogenesis of adult neural progenitor cells is not known. In this study, we tested whether Zfp488 could promote an oligodendrogenic fate in adult subventricular zone (SVZ) neural stem/progenitor cells (NSPCs). Using a cuprizone-induced demyelination model in mice, we examined the effect of retrovirus-mediated Zfp488 overexpression in SVZ NSPCs. Our results showed that Zfp488 efficiently promoted the differentiation of the SVZ NSPCs into mature oligodendrocytes in vivo. After cuprizone-induced demyelination injury, Zfp488-transduced mice also showed significant restoration of motor function to levels comparable to control mice. Together, these findings identify a previously unreported role for Zfp488 in adult oligodendrogenesis and functional remyelination after injury. PMID:22355521

Inducible knockdown of pregnancy-associated plasma protein-A gene expression in adult female mice extends life span.

PubMed

Bale, Laurie K; West, Sally A; Conover, Cheryl A

2017-08-01

Pregnancy-associated plasma protein-A (PAPP-A) knockout (KO) mice, generated through homologous recombination in embryonic stem cells, have a significantly increased lifespan compared to wild-type littermates. However, it is unknown whether this longevity advantage would pertain to PAPP-A gene deletion in adult animals. In the present study, we used tamoxifen (Tam)-inducible Cre recombinase-mediated excision of the floxed PAPP-A (fPAPP-A) gene in mice at 5 months of age. fPAPP-A mice, which were either positive (pos) or negative (neg) for Tam-Cre, received Tam treatment with quarterly boosters. Only female mice could be used with this experimental design. fPAPP-A/neg and fPAPP-A/pos mice had similar weights at the start of the experiment and showed equivalent weight gain. We found that fPAPP-A/pos mice had a significant extension of life span (P = 0.005). The median life span was increased by 21% for fPAPP-A/pos compared to fPAPP-A/neg mice. Analysis of mortality in life span quartiles indicated that the proportion of deaths of fPAPP-A/pos mice were lower than fPAPP-A/neg mice at young adult ages (P = 0.002 for 601-800 days) and higher than fPAPP-A/neg mice at older ages (P = 0.004 for >1000 days). Thus, survival curves and age-specific mortality indicate that female mice with knockdown of PAPP-A gene expression as adults have an extended healthy life span. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Huperzine A Provides Robust and Sustained Protection against Induced Seizures in Scn1a Mutant Mice

PubMed Central

Wong, Jennifer C.; Dutton, Stacey B. B.; Collins, Stephen D.; Schachter, Steven; Escayg, Andrew

2016-01-01

De novo loss-of-function mutations in the voltage-gated sodium channel (VGSC) SCN1A (encoding Nav1.1) are the main cause of Dravet syndrome (DS), a catastrophic early-life encephalopathy associated with prolonged and recurrent early-life febrile seizures (FSs), refractory afebrile epilepsy, cognitive and behavioral deficits, and a 15–20% mortality rate. SCN1A mutations also lead to genetic epilepsy with febrile seizures plus (GEFS+), which is an inherited disorder characterized by early-life FSs and the development of a range of adult epilepsy subtypes. Current antiepileptic drugs often fail to protect against the severe seizures and behavioral and cognitive deficits found in patients with SCN1A mutations. To address the need for more efficacious treatments for SCN1A-derived epilepsies, we evaluated the therapeutic potential of Huperzine A, a naturally occurring reversible acetylcholinesterase inhibitor. In CF1 mice, Hup A (0.56 or 1 mg/kg) was found to confer protection against 6 Hz-, pentylenetetrazole (PTZ)-, and maximal electroshock (MES)-induced seizures. Robust protection against 6 Hz-, MES-, and hyperthermia-induced seizures was also achieved following Hup A administration in mouse models of DS (Scn1a+/−) and GEFS+ (Scn1aRH/+). Furthermore, Hup A-mediated seizure protection was sustained during 3 weeks of daily injections in Scn1aRH/+ mutants. Finally, we determined that muscarinic and GABAA receptors play a role in Hup A-mediated seizure protection. These findings indicate that Hup A might provide a novel therapeutic strategy for increasing seizure resistance in DS and GEFS+, and more broadly, in other forms of refractory epilepsy. PMID:27799911

Paranodal permeability in `myelin mutants'

PubMed Central

Shroff, S.; Mierzwa, A.; Scherer, S.S.; Peles, E.; Arevalo, J.C.; Chao, M.V.; Rosenbluth, J.

2011-01-01

Fluorescent dextran tracers of varying sizes have been used to assess paranodal permeability in myelinated sciatic nerve fibers from control and three `myelin mutant' mice, Caspr-null, cst-null and shaking. We demonstrate that in all of these the paranode is permeable to small tracers (3kDa, 10kDa), which penetrate most fibers, and to larger tracers (40kDa, 70kDa), which penetrate far fewer fibers and move shorter distances over longer periods of time. Despite gross diminution in transverse bands in the Caspr-null and cst-null mice, the permeability of their paranodal junctions is equivalent to that in controls. Thus, deficiency of transverse bands in these mutants does not increase the permeability of their paranodal junctions to the dextrans we used, moving from the perinodal space through the paranode to the internodal periaxonal space. In addition, we show that the shaking mice, which have thinner myelin and shorter paranodes, show increased permeability to the same tracers despite the presence of transverse bands. We conclude that the extent of penetration of these tracers does not depend on the presence or absence of transverse bands but does depend on the length of the paranode and, in turn, on the length of `pathway 3', the helical extracellular pathway that passes through the paranode parallel to the lateral edge of the myelin sheath. PMID:21618613

Ablation of neurons expressing melanin-concentrating hormone (MCH) in adult mice improves glucose tolerance independent of MCH signaling.

PubMed

Whiddon, Benjamin B; Palmiter, Richard D

2013-01-30

Melanin-concentrating hormone (MCH)-expressing neurons have been ascribed many roles based on studies of MCH-deficient mice. However, MCH neurons express other neurotransmitters, including GABA, nesfatin, and cocaine-amphetamine-regulated transcript. The importance of these other signaling molecules made by MCH neurons remains incompletely characterized. To determine the roles of MCH neurons in vivo, we targeted expression of the human diphtheria toxin receptor (DTR) to the gene for MCH (Pmch). Within 2 weeks of diphtheria toxin injection, heterozygous Pmch(DTR/+) mice lost 98% of their MCH neurons. These mice became lean but ate normally and were hyperactive, especially during a fast. They also responded abnormally to psychostimulants. For these phenotypes, ablation of MCH neurons recapitulated knock-out of MCH, so MCH appears to be the critical neuromodulator released by these neurons. In contrast, MCH-neuron-ablated mice showed improved glucose tolerance when compared with MCH-deficient mutant mice and wild-type mice. We conclude that MCH neurons regulate glucose tolerance through signaling molecules other than MCH.

Female mice lack adult germ-line stem cells but sustain oogenesis using stable primordial follicles.

PubMed

Lei, Lei; Spradling, Allan C

2013-05-21

Whether or not mammalian females generate new oocytes during adulthood from germ-line stem cells to sustain the ovarian follicle pool has recently generated controversy. We used a sensitive lineage-labeling system to determine whether stem cells are needed in female adult mice to compensate for follicular losses and to directly identify active germ-line stem cells. Primordial follicles generated during fetal life are highly stable, with a half-life during adulthood of 10 mo, and thus are sufficient to sustain adult oogenesis without a source of renewal. Moreover, in normal mice or following germ-cell depletion with Busulfan, only stable, single oocytes are lineage-labeled, rather than cell clusters indicative of new oocyte formation. Even one germ-line stem cell division per 2 wk would have been detected by our method, based on the kinetics of fetal follicle formation. Thus, adult female mice neither require nor contain active germ-line stem cells or produce new oocytes in vivo.

AKAP13 Rho-GEF and PKD-Binding Domain Deficient Mice Develop Normally but Have an Abnormal Response to β-Adrenergic-Induced Cardiac Hypertrophy

PubMed Central

Spindler, Matthew J.; Burmeister, Brian T.; Huang, Yu; Hsiao, Edward C.; Salomonis, Nathan; Scott, Mark J.; Srivastava, Deepak; Carnegie, Graeme K.; Conklin, Bruce R.

2013-01-01

Background A-kinase anchoring proteins (AKAPs) are scaffolding molecules that coordinate and integrate G-protein signaling events to regulate development, physiology, and disease. One family member, AKAP13, encodes for multiple protein isoforms that contain binding sites for protein kinase A (PKA) and D (PKD) and an active Rho-guanine nucleotide exchange factor (Rho-GEF) domain. In mice, AKAP13 is required for development as null embryos die by embryonic day 10.5 with cardiovascular phenotypes. Additionally, the AKAP13 Rho-GEF and PKD-binding domains mediate cardiomyocyte hypertrophy in cell culture. However, the requirements for the Rho-GEF and PKD-binding domains during development and cardiac hypertrophy are unknown. Methodology/Principal Findings To determine if these AKAP13 protein domains are required for development, we used gene-trap events to create mutant mice that lacked the Rho-GEF and/or the protein kinase D-binding domains. Surprisingly, heterozygous matings produced mutant mice at Mendelian ratios that had normal viability and fertility. The adult mutant mice also had normal cardiac structure and electrocardiograms. To determine the role of these domains during β-adrenergic-induced cardiac hypertrophy, we stressed the mice with isoproterenol. We found that heart size was increased similarly in mice lacking the Rho-GEF and PKD-binding domains and wild-type controls. However, the mutant hearts had abnormal cardiac contractility as measured by fractional shortening and ejection fraction. Conclusions These results indicate that the Rho-GEF and PKD-binding domains of AKAP13 are not required for mouse development, normal cardiac architecture, or β-adrenergic-induced cardiac hypertrophic remodeling. However, these domains regulate aspects of β-adrenergic-induced cardiac hypertrophy. PMID:23658642

Vaccination with Brucella abortus rough mutant RB51 protects BALB/c mice against virulent strains of Brucella abortus, Brucella melitensis, and Brucella ovis.

PubMed Central

Jiménez de Bagüés, M P; Elzer, P H; Jones, S M; Blasco, J M; Enright, F M; Schurig, G G; Winter, A J

1994-01-01

Vaccination of BALB/c mice with live Brucella abortus RB51, a stable rough mutant, produced protection against challenge with virulent strains of Brucella abortus, Brucella melitensis, and Brucella ovis. Passive-transfer experiments indicated that vaccinated mice were protected against B. abortus 2308 through cell-mediated immunity, against B. ovis PA through humoral immunity, and against B. melitensis 16M through both forms of immunity. Live bacteria were required for the induction of protective cell-mediated immunity; vaccination with whole killed cells of strain RB51 failed to protect mice against B. abortus 2308 despite development of good delayed-type hypersensitivity reactions. Protective antibodies against the heterologous species were generated in vaccinated mice primarily through anamnestic responses following challenge infections. Growth of the antigenically unrelated bacterium Listeria monocytogenes in the spleens of vaccinated mice indicated that nonspecific killing by residual activated macrophages contributed minimally to protection. These results encourage the continued investigation of strain RB51 as an alternative vaccine against heterologous Brucella species. However, its usefulness against B. ovis would be limited if, as suggested here, epitopes critical for protective cell-mediated immunity are not shared between B. abortus and B. ovis. Images PMID:7927779

Laser Interferometer Measurements of the Viscoelastic Properties of Tectorial Membrane Mutants

NASA Astrophysics Data System (ADS)

Jones, Gareth; Russell, Ian; Lukashkin, Andrei

2011-11-01

The visco-elastic properties of the tectorial membrane (TM) can be determined by measuring the propagation velocity of travelling waves over a range of frequencies. This study presents a new method using laser interferometry and compares the TM's material properties (sheer storage modulus, G' and viscosity, η) at basal and apical locations in wild-type mice and basal locations of three mutant groups (TectaY1870C/+, Tectb-/- and Otoa-/-). The G' and η values calculated for the wild-type mice are similar to estimates derived using other methods whereas the mutant groups all exhibit slower wave propagation velocities and reduced longitudinal coupling.

Induction of Unconventional T Cells by a Mutant Mycobacterium bovis BCG Strain Formulated in Cationic Liposomes Correlates with Protection against Mycobacterium tuberculosis Infections of Immunocompromised Mice

PubMed Central

Yabe, Idalia; Morris, Sheldon; Cowley, Siobhan

2016-01-01

Earlier studies aimed at defining protective immunity induced by Mycobacterium bovis BCG immunization have largely focused on the induction of antituberculosis CD4+ and CD8+ T cell responses. Here we describe a vaccine consisting of a BCGΔmmaA4 deletion mutant formulated in dimethyl dioctadecyl-ammonium bromide (DDA) with d-(+)-trehalose 6,6′-dibehenate (TDB) (DDA/TDB) adjuvant (A4/Adj) that protected TCRδ−/− mice depleted of CD4+, CD8+, and NK1.1+ T cells against an aerosol challenge with M. tuberculosis. These mice were significantly protected relative to mice immunized with a nonadjuvanted BCGΔmmaA4 (BCG-A4) mutant and nonvaccinated controls at 2 months and 9 months postvaccination. In the absence of all T cells following treatment with anti-Thy1.2 antibody, the immunized mice lost the ability to control the infection. These results indicate that an unconventional T cell population was mediating protection in the absence of CD4+, CD8+, NK1.1+, and TCRγδ T cells and could exhibit memory. Focusing on CD4− CD8− double-negative (DN) T cells, we found that these cells accumulated in the lungs postchallenge significantly more in A4/Adj-immunized mice and induced significantly greater frequencies of pulmonary gamma interferon (IFN-γ)-producing cells than were seen in the nonvaccinated or nonadjuvanted BCG control groups. Moreover, pulmonary DN T cells from the A4/Adj group exhibited significantly higher IFN-γ integrated median fluorescence intensity (iMFI) values than were seen in the control groups. We also showed that enriched DN T cells from mice immunized with A4/Adj could control mycobacterial growth in vitro significantly better than naive whole-spleen cells. These results suggest that formulating BCG in DDA/TDB adjuvant confers superior protection in immunocompromised mice and likely involves the induction of long-lived memory DN T cells. PMID:27226281

Sleep apneas are increased in mice lacking monoamine oxidase A.

PubMed

Real, Caroline; Popa, Daniela; Seif, Isabelle; Callebert, Jacques; Launay, Jean-Marie; Adrien, Joëlle; Escourrou, Pierre

2007-10-01

Alterations in the serotonin (5-HT) system have been suggested as a mechanism of sleep apnea in humans and rodents. The objective is to evaluate the contribution of 5-HT to this disorder. We studied sleep and breathing (whole-body plethysmography) in mutant mice that lack monoamine oxidase A (MAOA) and have increased concentrations of monoamines, including 5-HT. Compared to wild-type mice, the mutants showed similar amounts of slow wave sleep (SWS) and rapid eye movement sleep (REMS), but exhibited a 3-fold increase in SWS and REMS apnea indices. Acute administration of the MAOA inhibitor clorgyline decreased REMS amounts and increased the apnea index in wild-type but not mutant mice. Parachlorophenylalanine, a 5-HT synthesis inhibitor, reduced whole brain concentrations of 5-HT in both strains, and induced a decrease in apnea index in mutant but not wild-type mice. Our results show that MAOA deficiency is associated with increased sleep apnea in mice and suggest that an acute or chronic excess of 5-HT contributes to this phenotype.

Subpial Adeno-associated Virus 9 (AAV9) Vector Delivery in Adult Mice.

PubMed

Tadokoro, Takahiro; Miyanohara, Atsushi; Navarro, Michael; Kamizato, Kota; Juhas, Stefan; Juhasova, Jana; Marsala, Silvia; Platoshyn, Oleksandr; Curtis, Erik; Gabel, Brandon; Ciacci, Joseph; Lukacova, Nada; Bimbova, Katarina; Marsala, Martin

2017-07-13

The successful development of a subpial adeno-associated virus 9 (AAV9) vector delivery technique in adult rats and pigs has been reported on previously. Using subpially-placed polyethylene catheters (PE-10 or PE-5) for AAV9 delivery, potent transgene expression through the spinal parenchyma (white and gray matter) in subpially-injected spinal segments has been demonstrated. Because of the wide range of transgenic mouse models of neurodegenerative diseases, there is a strong desire for the development of a potent central nervous system (CNS)-targeted vector delivery technique in adult mice. Accordingly, the present study describes the development of a spinal subpial vector delivery device and technique to permit safe and effective spinal AAV9 delivery in adult C57BL/6J mice. In spinally immobilized and anesthetized mice, the pia mater (cervical 1 and lumbar 1-2 spinal segmental level) was incised with a sharp 34 G needle using an XYZ manipulator. A second XYZ manipulator was then used to advance a blunt 36G needle into the lumbar and/or cervical subpial space. The AAV9 vector (3-5 µL; 1.2 x 10 13 genome copies (gc)) encoding green fluorescent protein (GFP) was then injected subpially. After injections, neurological function (motor and sensory) was assessed periodically, and animals were perfusion-fixed 14 days after AAV9 delivery with 4% paraformaldehyde. Analysis of horizontal or transverse spinal cord sections showed transgene expression throughout the entire spinal cord, in both gray and white matter. In addition, intense retrogradely-mediated GFP expression was seen in the descending motor axons and neurons in the motor cortex, nucleus ruber, and formatio reticularis. No neurological dysfunction was noted in any animals. These data show that the subpial vector delivery technique can successfully be used in adult mice, without causing procedure-related spinal cord injury, and is associated with highly potent transgene expression throughout the spinal neuraxis.

BAX and tumor suppressor TRP53 are important in regulating mutagenesis in spermatogenic cells in mice.

PubMed

Xu, Guogang; Vogel, Kristine S; McMahan, C Alex; Herbert, Damon C; Walter, Christi A

2010-12-01

During the first wave of spermatogenesis, and in response to ionizing radiation, elevated mutant frequencies are reduced to a low level by unidentified mechanisms. Apoptosis is occurring in the same time frame that the mutant frequency declines. We examined the role of apoptosis in regulating mutant frequency during spermatogenesis. Apoptosis and mutant frequencies were determined in spermatogenic cells obtained from Bax-null or Trp53-null mice. The results showed that spermatogenic lineage apoptosis was markedly decreased in Bax-null mice and was accompanied by a significantly increased spontaneous mutant frequency in seminiferous tubule cells compared to that of wild-type mice. Apoptosis profiles in the seminiferous tubules for Trp53-null were similar to control mice. Spontaneous mutant frequencies in pachytene spermatocytes and in round spermatids from Trp53-null mice were not significantly different from those of wild-type mice. However, epididymal spermatozoa from Trp53-null mice displayed a greater spontaneous mutant frequency compared to that from wild-type mice. A greater proportion of spontaneous transversions and a greater proportion of insertions/deletions 15 days after ionizing radiation were observed in Trp53-null mice compared to wild-type mice. Base excision repair activity in mixed germ cell nuclear extracts prepared from Trp53-null mice was significantly lower than that for wild-type controls. These data indicate that BAX-mediated apoptosis plays a significant role in regulating spontaneous mutagenesis in seminiferous tubule cells obtained from neonatal mice, whereas tumor suppressor TRP53 plays a significant role in regulating spontaneous mutagenesis between postmeiotic round spermatid and epididymal spermatozoon stages of spermiogenesis.

The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

PubMed Central

Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart

2014-01-01

Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glomerular hypertrophy was induced by progressive partial nephrectomies. Again, no significant podocyte replenishment was observed. Rather, labeled PECs exclusively invaded segments of the tuft affected by glomerulosclerosis, consistent with our previous findings. We next reassessed PEC recruitment in juvenile mice using a different reporter mouse and confirmed significant recruitment of labeled PECs onto the glomerular tuft. Moreover, some labeled cells on Bowman’s capsule expressed podocyte markers, and cells on Bowman’s capsule were also directly labeled in juvenile podocyte-specific Pod-rtTA transgenic mice. In 6-week-old mice, however, cells on Bowman’s capsule no longer expressed podocyte-specific markers. Similarly, in human kidneys, some cells on Bowman’s capsule expressed the podocyte marker synaptopodin from 2 weeks to 2 years of age but not at 7 years of age. In summary, podocyte regeneration from PECs could not be detected in aging mice or models of glomerular hypertrophy. We propose that a small fraction of committed podocytes reside on Bowman’s capsule close to the vascular stalk and are recruited onto the glomerular tuft during infancy to adolescence in mice and humans. PMID:24408873

Neurobehavioral Mutants Identified in an ENU Mutagenesis Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, Melloni N.; Dunning, Jonathan P; Wiley, Ronald G

2007-01-01

We report on a behavioral screening test battery that successfully identified several neurobehavioral mutants among a large-scale ENU-mutagenized mouse population. Large numbers of ENU mutagenized mice were screened for abnormalities in central nervous system function based on abnormal performance in a series of behavior tasks. We developed and employed a high-throughput screen of behavioral tasks to detect behavioral outliers. Twelve mutant pedigrees, representing a broad range of behavioral phenotypes, have been identified. Specifically, we have identified two open field mutants (one displaying hyper-locomotion, the other hypo-locomotion), four tail suspension mutants (all displaying increased immobility), one nociception mutant (displaying abnormal responsivenessmore » to thermal pain), two prepulse inhibition mutants (displaying poor inhibition of the startle response), one anxiety-related mutant (displaying decreased anxiety in the light/dark test), and one learning and memory mutant (displaying reduced response to the conditioned stimulus) These findings highlight the utility of a set of behavioral tasks used in a high throughput screen to identify neurobehavioral mutants. Further analysis (i.e., behavioral and genetic mapping studies) of mutants is in progress with the ultimate goal of identification of novel genes and mouse models relevant to human disorders as well as the identification of novel therapeutic targets.« less

EPHRIN-A5 REGULATES INTER-MALE AGGRESSION IN MICE

PubMed Central

Sheleg, Michal; Yochum, Carrie L.; Richardson, Jason R.; Wagner, George C.; Zhou, Renping

2015-01-01

The Eph family of receptor tyrosine kinases play key roles in both the patterning of the developing nervous system and neural plasticity in the mature brain. To determine functions of ephrin-A5, a GPI-linked ligand to the Eph receptors, in animal behavior regulations, we examined effects of its inactivation on male mouse aggression. When tested in the resident-intruder paradigm for offensive aggression, ephrin-A5-mutant animals (ephrin-A5−/−) exhibited severe reduction in conspecific aggression compared to wild-type controls. On the contrary, defensive aggression in the form of target biting was higher in ephrin-A5−/− mice, indicating that the mutant mice are capable of attacking behavior. In addition, given the critical role of olfaction in aggressive behavior, we examined the ability of the ephrin-A5−/− mice to smell and found no differences between the mutant and control animals. Testosterone levels in the mutant mice were also found to be within the normal range. Taken together, our data reveal a new role of ephrin-A5 in the regulation of aggressive behavior in mice. PMID:25746458

Drosophila mutants of the autism candidate gene neurobeachin (rugose) exhibit neuro-developmental disorders, aberrant synaptic properties, altered locomotion, and impaired adult social behavior and activity patterns.

PubMed

Wise, Alexandria; Tenezaca, Luis; Fernandez, Robert W; Schatoff, Emma; Flores, Julian; Ueda, Atsushi; Zhong, Xiaotian; Wu, Chun-Fang; Simon, Anne F; Venkatesh, Tadmiri

2015-01-01

Autism spectrum disorder (ASD) is a neurodevelopmental disorder in humans characterized by complex behavioral deficits, including intellectual disability, impaired social interactions, and hyperactivity. ASD exhibits a strong genetic component with underlying multigene interactions. Candidate gene studies have shown that the neurobeachin (NBEA) gene is disrupted in human patients with idiopathic autism ( Castermans et al., 2003 ). The NBEA gene spans the common fragile site FRA 13A and encodes a signal scaffold protein ( Savelyeva et al., 2006 ). In mice, NBEA has been shown to be involved in the trafficking and function of a specific subset of synaptic vesicles. ( Medrihan et al., 2009 ; Savelyeva et al., 2006 ). Rugose (rg) is the Drosophila homolog of the mammalian and human NBEA. Our previous genetic and molecular analyses have shown that rg encodes an A kinase anchor protein (DAKAP 550), which interacts with components of the epidermal growth factor receptor or EGFR and Notch-mediated signaling pathways, facilitating cross talk between these and other pathways ( Shamloula et al., 2002 ). We now present functional data from studies on the larval neuromuscular junction that reveal abnormal synaptic architecture and physiology. In addition, adult rg loss-of-function mutants exhibit defective social interactions, impaired habituation, aberrant locomotion, and hyperactivity. These results demonstrate that Drosophila NBEA (rg) mutants exhibit phenotypic characteristics reminiscent of human ASD and thus could serve as a genetic model for studying ASDs.

Lyophilized airborne Clostridium botulinum spores as inocula that intestinally colonize antimicrobially pretreated adult mice.

PubMed Central

Sugiyama, H; Prather, J L; Woller, M J

1986-01-01

Adult mice, made susceptible to Clostridium botulinum by feedings of metronidazole, were immobilized with an anesthetic and held for 30 min in isolators in which a fine powder of lyophilized pathogen spores was made airborne. Exposed mice were surface decontaminated before being kept for 2 days in holding isolators. Mice were intestinally colonized by the pathogen. Colonization rates were related to spore numbers (10(4) to 10(7) type A or B) seeded into isolators. PMID:3531017

Early gestational exposure to moderate concentrations of ethanol alters adult behaviour in C57BL/6J mice.

PubMed

Sanchez Vega, Michelle C; Chong, Suyinn; Burne, Thomas H J

2013-09-01

Alcohol consumption during pregnancy has deleterious effects on the developing foetus ranging from subtle physical deficits to severe behavioural abnormalities and is encompassed under a broad umbrella term, foetal alcohol spectrum disorders (FASD). High levels of exposure show distinct effects, whereas the consequences of moderate exposures have been less well studied. The aim of this study was to examine the effects of a moderate dose ethanol exposure using an ad libitum drinking procedure during the first eight days of gestation in mice on the behavioural phenotype of adult offspring. Adult female C57Bl/6J mice were mated and exposed to either 10% (v/v) ethanol or water for the first 8 days of gestation (GD 0-8), and then offered water for the rest of gestation. Early developmental milestone achievement was assessed in offspring at postnatal days (P) 7, 14 and 21. Adult offspring underwent a comprehensive battery of behavioural tests to examine a range of behavioural domains including locomotion, exploration, anxiety, social behaviour, learned helplessness, sensorimotor gating, and nociception, as well as spatial memory in a water maze. Ethanol-exposed mice had similar postnatal developmental trajectories to water-exposed mice. However, the ethanol-exposed mice showed increased hyperlocomotion at P 14, 21 and 70 (p<0.05). Increased exploration and heightened motivation were also observed in adult mice. Furthermore, ethanol-exposed mice showed a significant improvement in memory in the water maze. The main findings were that mice had persistent and long lasting alterations in behaviour, including hyperactivity and enhanced spatial memory. These data suggest that even moderate dose ethanol exposure in early gestation has long term consequences on brain function and behaviour in mice. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Mutant Kras copy number defines metabolic reprogramming and therapeutic susceptibilities

PubMed Central

Kerr, Emma; Gaude, Edoardo; Turrell, Frances; Frezza, Christian; Martins, Carla P

2016-01-01

Summary The RAS/MAPK-signalling pathway is frequently deregulated in non-small cell lung cancer (NSCLC), often through KRAS activating mutations1-3. A single endogenous mutant Kras allele is sufficient to promote lung tumour formation in mice but malignant progression requires additional genetic alterations4-7. We recently showed that advanced lung tumours from KrasG12D/+;p53-null mice frequently exhibit KrasG12D allelic enrichment (KrasG12D/Kraswild-type>1)7, implying that mutant Kras copy gains are positively selected during progression. Through a comprehensive analysis of mutant Kras homozygous and heterozygous MEFs and lung cancer cells we now show that these genotypes are phenotypically distinct. In particular, KrasG12D/G12D cells exhibit a glycolytic switch coupled to increased channelling of glucose-derived metabolites into the TCA cycle and glutathione biosynthesis, resulting in enhanced glutathione-mediated detoxification. This metabolic rewiring is recapitulated in mutant KRAS homozygous NSCLC cells and in vivo, in spontaneous advanced murine lung tumours (which display a high frequency of KrasG12D copy gain), but not in the corresponding early tumours (KrasG12D heterozygous). Finally, we demonstrate that mutant Kras copy gain creates unique metabolic dependences that can be exploited to selectively target these aggressive mutant Kras tumours. Our data demonstrate that mutant Kras lung tumours are not a single disease but rather a heterogeneous group comprised of two classes of tumours with distinct metabolic profiles, prognosis and therapeutic susceptibility, which can be discriminated based on their relative mutant allelic content. We also provide the first in vivo evidence of metabolic rewiring during lung cancer malignant progression. PMID:26909577

Bone marrow-specific knock-in of a non-activatable Ikkα kinase mutant influences haematopoiesis but not atherosclerosis in Apoe-deficient mice.

PubMed

Tilstam, Pathricia V; Gijbels, Marion J; Habbeddine, Mohamed; Cudejko, Céline; Asare, Yaw; Theelen, Wendy; Zhou, Baixue; Döring, Yvonne; Drechsler, Maik; Pawig, Lukas; Simsekyilmaz, Sakine; Koenen, Rory R; de Winther, Menno P J; Lawrence, Toby; Bernhagen, Jürgen; Zernecke, Alma; Weber, Christian; Noels, Heidi

2014-01-01

The Ikkα kinase, a subunit of the NF-κB-activating IKK complex, has emerged as an important regulator of inflammatory gene expression. However, the role of Ikkα-mediated phosphorylation in haematopoiesis and atherogenesis remains unexplored. In this study, we investigated the effect of a bone marrow (BM)-specific activation-resistant Ikkα mutant knock-in on haematopoiesis and atherosclerosis in mice. Apolipoprotein E (Apoe)-deficient mice were transplanted with BM carrying an activation-resistant Ikkα gene (Ikkα(AA/AA)Apoe(-/-) ) or with Ikkα(+/+)Apoe(-/-) BM as control and were fed a high-cholesterol diet for 8 or 13 weeks. Interestingly, haematopoietic profiling by flow cytometry revealed a significant decrease in B-cells, regulatory T-cells and effector memory T-cells in Ikkα(AA/AA)Apoe(-/-) BM-chimeras, whereas the naive T-cell population was increased. Surprisingly, no differences were observed in the size, stage or cellular composition of atherosclerotic lesions in the aorta and aortic root of Ikkα(AA/AA)Apoe(-/-) vs Ikkα(+/+)Apoe(-/-) BM-transplanted mice, as shown by histological and immunofluorescent stainings. Necrotic core sizes, apoptosis, and intracellular lipid deposits in aortic root lesions were unaltered. In vitro, BM-derived macrophages from Ikkα(AA/AA)Apoe(-/-) vs Ikkα(+/+)Apoe(-/-) mice did not show significant differences in the uptake of oxidized low-density lipoproteins (oxLDL), and, with the exception of Il-12, the secretion of inflammatory proteins in conditions of Tnf-α or oxLDL stimulation was not significantly altered. Furthermore, serum levels of inflammatory proteins as measured with a cytokine bead array were comparable. Our data reveal an important and previously unrecognized role of haematopoietic Ikkα kinase activation in the homeostasis of B-cells and regulatory T-cells. However, transplantation of Ikkα(AA) mutant BM did not affect atherosclerosis in Apoe(-/-) mice. This suggests that the diverse functions of Ikk

Conditional rescue of protein kinase C epsilon regulates ethanol preference and hypnotic sensitivity in adult mice.

PubMed

Choi, Doo-Sup; Wang, Dan; Dadgar, Jahan; Chang, Wesley S; Messing, Robert O

2002-11-15

Conventional gene targeting is a powerful tool to study the influence of specific genes on behavior. However, conclusions relevant for adult animals are limited by consequences of gene loss during development. Mice lacking protein kinase C epsilon (PKCepsilon) consume less alcohol and show greater acute sensitivity to alcohol than do wild-type mice. There are no selective inhibitors of PKCepsilon that can be administered systemically and cross the blood-brain barrier to test whether these phenotypes result from loss of PKCepsilon during development or in adulthood. Here we used conditional expression of PKCepsilon in the basal forebrain, amygdala, and cerebellum to rescue wild-type responses to alcohol in adult PKCepsilon(-/-) mice. Subsequent suppression of transgenic PKCepsilon restored PKCepsilon(-/-) behaviors. These findings establish that PKCepsilon signaling in the adult brain regulates alcohol consumption and sensitivity. If this extends to humans, then PKCepsilon inhibitors might prove useful as novel therapeutics for alcoholism.

Endothelial deletion of ADAM17 in mice results in defective remodeling of the semilunar valves and cardiac dysfunction in adults.

PubMed

Wilson, Carole L; Gough, Peter J; Chang, Cindy A; Chan, Christina K; Frey, Jeremy M; Liu, Yonggang; Braun, Kathleen R; Chin, Michael T; Wight, Thomas N; Raines, Elaine W

2013-01-01

Global inactivation of the metalloproteinase ADAM17 during mouse development results in perinatal lethality and abnormalities of the heart, including late embryonic cardiomegaly and thickened semilunar and atrioventricular valves. These defects have been attributed in part to a lack of ADAM17-mediated processing of HB-EGF, as absence of soluble HB-EGF results in similar phenotypes. Because valvular mesenchymal cells are largely derived from cardiac endothelial cells, we generated mice with a floxed Adam17 allele and crossed these animals with Tie2-Cre transgenics to focus on the role of endothelial ADAM17 in valvulogenesis. We find that although hearts from late-stage embryos with ablation of endothelial ADAM17 appear normal, an increase in valve size and cell number is evident, but only in the semilunar cusps. Unlike Hbegf(-/-) valves, ADAM17-null semilunar valves do not differ from controls in acute cell proliferation at embryonic day 14.5 (E14.5), suggesting compensatory processing of HB-EGF. However, levels of the proteoglycan versican are significantly reduced in mutant hearts early in valve remodeling (E12.5). After birth, aortic valve cusps from mutants are not only hyperplastic but also show expansion of the glycosaminoglycan-rich component, with the majority of adults exhibiting aberrant compartmentalization of versican and increased deposition of collagen. The inability of mutant outflow valve precursors to transition into fully mature cusps is associated with decreased postnatal viability, progressive cardiomegaly, and systolic dysfunction. Together, our data indicate that ADAM17 is required in valvular endothelial cells for regulating cell content as well as extracellular matrix composition and organization in semilunar valve remodeling and homeostasis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Anemia in new congenital adult type polycystic kidney mice.

PubMed

Koumegawa, J; Nagano, N; Arai, H; Wada, M; Kusaka, M; Takahashi, H

1991-12-01

Mechanisms for the development of anemia and the effects of recombinant human erythropoietin (r-HuEPO) on hematological parameters were studied in new congenital adult type polycystic kidney (DBA/2FG-pcy) mice. The majority of DBA/2FG-pcy mice showed progressive anemia and an elevation of blood urea nitrogen, while a minority showed progressive anemia following polycythemia. Kidneys with numerous cysts in the cortex and medulla occupied virtually the entire abdominal cavity, and the combined kidney weight taken as a percentage of body weight reached 13.5% in the DBA/2FG-pcy mouse. The osmotic fragility of DBA/2FG-pcy mice erythrocytes was significantly increased compared with that of normal control mice. In addition, two-fold increases in serum EPO levels, determined by radioimmunoassay, and a decreased number of colony forming unit-erythroid (CFU-E) were observed in the DBA/2FG-pcy mice. The administration of r-HuEPO during anemia significantly increased the red blood cell count, hemoglobin concentration, hematocrit and reticulocyte percentage in a dose-dependent manner. These findings indicate that anemia in the DBA/2FG-pcy mouse is due to increased fragility of erythrocytes, a deficiency in EPO for the degree of anemia and a decreased number or a decreased response of erythroid progenitor cells. We suggest that the DBA/2FG-pcy mouse is a useful spontaneous model of chronic progressive renal failure.

Nuclei pulposi formation from the embryonic notochord occurs normally in GDF5-deficient mice

PubMed Central

Maier, Jennifer A.; Harfe, Brian D.

2011-01-01

Study Design The transition of the mouse embryonic notochord into nuclei pulposi was determined (“fate mapped”) in vivo in GDF-5 null mice using the Shhcre and R26R alleles. Objective To determine if abnormal nuclei pulposi formation from the embryonic notochord was responsible for defects present in adult nuclei pulposi of Gdf-5 null mice. Summary of Background Data The development, maintenance, and degeneration of the intervertebral disc are not understood. Previously, we demonstrated that all cells in the adult nucleus pulposus of normal mice are derived from the embryonic notochord. Gdf-5 null mice have been reported to contain intervertebral discs in which the nucleus pulposus is abnormal. It is currently unclear if disc defects in Gdf-5 null mice arise during the formation of nuclei pulposi from the notochord during embryogenesis or resulted from progressive postnatal degeneration of nuclei pulposi. Methods Gdf-5 mRNA expression was examined in the discs of wild-type embryos by RNA in situ hybridization to determine when and where this gene was expressed. To examine nucleus pulposus formation in Gdf-5 null mice, intervertebral discs in which embryonic notochord cells were marked were analyzed in newborn and 24 week old mice. Results Our Gdf-5 mRNA in situ experiments determined that this gene is localized to the annulus fibrosus and not the nucleus pulposus in mouse embryos. Notochord fate mapping experiments revealed that notochord cells in Gdf-5 null mice correctly form nuclei pulposi. Conclusion Our data suggest that the defects reported in the nucleus pulposus of adult Gdf-5 null mice do not result from abnormal patterning of the embryonic notochord. The use of mouse alleles to mark cells that produce all cell types that reside in the adult nucleus pulposus will allow for a detailed examination of disc formation in other mouse mutants that have been reported to contain disc defects. PMID:21278629

Expansion of stem cells counteracts age-related mammary regression in compound Timp1/Timp3 null mice.

PubMed

Jackson, Hartland W; Waterhouse, Paul; Sinha, Ankit; Kislinger, Thomas; Berman, Hal K; Khokha, Rama

2015-03-01

Age is the primary risk factor for breast cancer in women. Bipotent basal stem cells actively maintain the adult mammary ductal tree, but with age tissues atrophy. We show that cell-extrinsic factors maintain the adult stem cell pool during ageing and dictate tissue stoichiometry. Mammary stem cells spontaneously expand more than 11-fold in virgin adult female mice lacking specific genes for TIMPs, the natural metalloproteinase inhibitors. Compound Timp1/Timp3 null glands exhibit Notch activation and accelerated gestational differentiation. Proteomics of mutant basal cells uncover altered cytoskeletal and extracellular protein repertoires, and we identify aberrant mitotic spindle orientation in these glands, a process that instructs asymmetric cell division and fate. We find that progenitor activity normally declines with age, but enriched stem/progenitor pools prevent tissue regression in Timp mutant mammary glands without affecting carcinogen-induced cancer susceptibility. Thus, improved stem cell content can extend mouse mammary tissue lifespan without altering cancer risk in this mouse model.

Dental and Cranial Pathologies in Mice Lacking the Cl−/H+-Exchanger ClC-7

PubMed Central

WEN, Xin; LACRUZ, Rodrigo S.; PAINE, Michael L.

2015-01-01

ClC-7 is a 2Cl−/1H+-exchanger expressed at late endosomes and lysosomes, as well as the ruffled border of osteoclasts. ClC-7 deficiencies in mice and humans lead to impaired osteoclast function and therefore osteopetrosis. Failure of tooth eruption is also apparent in ClC-7 mutant animals, and this has been attributed to the osteoclast dysfunction and the subsequent defect in alveolar bone resorptive activity surrounding tooth roots. Ameloblasts also express ClC-7, and this study aims to determine the significance of ClC-7 in enamel formation by examining the dentitions of ClC-7 mutant mice. Micro-CT analysis revealed that the molar teeth of 3-week old ClC-7 mutant mice had no roots, and the incisors were smaller than their age-matched controls. Despite these notable developmental differences, the enamel and dentin densities of the mutant mice were comparable to those of the wild type littermates. Scanning electron microscopy (SEM) showed normal enamel crystallite and prismatic organization in the ClC-7 mutant mice, although the enamel was thinner (hypoplastic) than in controls. These results suggested that ClC-7 was not critical to enamel and dentin formation, and the observed tooth defects may be related more to a resulting alveolar bone phenotype. Micro-CT analysis also revealed abnormal features in the calvarial bones of the mutant mice. The cranial sutures in ClC-7 mutant mice remained open compared to the closed sutures seen in the control mice at 3 weeks. These data demonstrate that ClC-7 deficiency impacts the development of the dentition and calvaria, but does not significantly disrupt amelogenesis. PMID:25663454

Full Length Human Mutant Huntingtin with a Stable Polyglutamine Repeat Can Elicit Progressive and Selective Neuropathogenesis in BACHD Mice

PubMed Central

Gray, Michelle; Shirasaki, Dyna I.; Cepeda, Carlos; Andre, Veronique M.; Wilburn, Brian; Lu, Xiao-Hong; Tao, Jifang; Yamazaki, Irene; Li, Shi-Hua; Sun, Yi E.; Li, Xiao-Jiang; Levine, Michael S.; William Yang, X

2008-01-01

To elucidate the pathogenic mechanisms in Huntington’s disease (HD) elicited by expression of full-length human mutant huntingtin (fl-mhtt), a Bacterial Artificial Chromosome (BAC)-mediated transgenic mouse model (BACHD) was developed expressing fl-mhtt with 97 glutamine repeats under the control of endogenous htt regulatory machinery on the BAC. BACHD mice exhibit progressive motor deficits, neuronal synaptic dysfunction, and late-onset selective neuropathology, which includes significant cortical and striatal atrophy and striatal dark neuron degeneration. Power analyses reveal the robustness of the behavioral and neuropathological phenotypes, suggesting BACHD as a suitable fl-mhtt mouse model for preclinical studies. Further analyses of BACHD mice provide additional insights into how mhtt may elicit neuropathogenesis. First, unlike prior fl-mhtt mouse models, BACHD mice reveal that the slowly progressive and selective pathogenic process in HD mouse brains can occur without early and diffuse nuclear accumulation of aggregated mhtt (i.e. as detected by immunostaining with the EM48 antibody). Instead, a relatively steady-state level of predominantly full-length mhtt and a small amount of mhtt N-terminal fragments are sufficient to elicit the disease process. Second, the polyglutamine repeat within fl-mhtt in BACHD mice is encoded by a mixed CAA-CAG repeat, which is stable in both the germline and somatic tissues including the cortex and striatum at the onset of neuropathology. Therefore, our results suggest that somatic repeat instability does not play a necessary role in selective neuropathogenesis in BACHD mice. In summary, the BACHD model constitutes a novel and robust in vivo paradigm for the investigation of HD pathogenesis and treatment. PMID:18550760

Neonatal blockade of GABA-A receptors alters behavioral and physiological phenotypes in adult mice.

PubMed

Salari, Ali-Akbar; Amani, Mohammad

2017-04-01

Gamma-aminobutyric acid (GABA) plays an inhibitory role in the mature brain, and has a complex and bidirectional effect in different parts of the immature brain which affects proliferation, migration and differentiation of neurons during development. There is also increasing evidence suggesting that activation or blockade of the GABA-A receptors during early life can induce brain and behavioral abnormalities in adulthood. We investigated whether neonatal blockade of the GABA-A receptors by bicuculline can alter anxiety- and depression-like behaviors, body weight, food intake, corticosterone and testosterone levels in adult mice (postnatal days 80-95). To this end, neonatal mice were treated with either DMSO or bicuculline (70, 150 and 300μg/kg) during postnatal days 7, 9 and 11. When grown to adulthood, mice were exposed to behavioral tests to measure anxiety- (elevated plus-maze and light-dark box) and depression-like behaviors (tail suspension test and forced swim test). Stress-induced serum corticosterone and testosterone levels, body weight and food intake were also evaluated. Neonatal bicuculline exposure at dose of 300μg/kg decreased anxiety-like behavior, stress-induced corticosterone levels and increased testosterone levels, body weight and food intake, without significantly influencing depression-like behavior in adult male mice. However, no significant changes in these parameters were observed in adult females. These findings suggest that neonatal blockade of GABA-A receptors affects anxiety-like behavior, physiological and hormonal parameters in a sex-dependent manner in mice. Taken together, these data corroborate the concept that GABA-A receptors during early life have an important role in programming neurobehavioral phenotypes in adulthood. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

Reduced wheel running and blunted effects of voluntary exercise in LPA1-null mice: The importance of assessing the amount of running in transgenic mice studies

PubMed Central

Castilla-Ortega, Estela; Rosell-Valle, Cristina; Blanco, Eduardo; Pedraza, Carmen; Chun, Jerold; de Fonseca, Fernando Rodríguez; Estivill-Torrús, Guillermo; Santín, Luis J.

2014-01-01

This work was aimed to assess whether voluntary exercise rescued behavioral and hippocampal alterations in mice lacking the lysophosphatidic acid LPA1 receptor (LPA1-null mice), studying the potential relationship between the amount of exercise performed and its effects. Normal and LPA1-null mice underwent 23 days of free wheel running and were tested for open-field behavior and adult hippocampal neurogenesis (cell proliferation, immature neurons, cell survival). Running decreased anxiety-like behavior in both genotypes but increased exploration only in the normal mice. While running affected all neurogenesis-related measures in normal mice (especially in the suprapyramidal blade of the dentate gyrus), only a moderate increase in cell survival was found in the mutants. Importantly, the LPA1-nulls showed notably reduced running. Analysis suggested that defective running in the LPA1-null mice could contribute to explain the scarce benefit of the voluntary exercise treatment. On the other hand, a literature review revealed that voluntary exercise is frequently used to modulate behavior and the hippocampus in transgenic mice, but half of the studies did not assess the quantity of running, overlooking any potential running impairments. This study adds evidence to the relevance of the quantity of exercise performed, emphasizing the importance of its assessment in transgenic mice research. PMID:24055600

Delayed stabilization of dendritic spines in fragile X mice.

PubMed

Cruz-Martín, Alberto; Crespo, Michelle; Portera-Cailliau, Carlos

2010-06-09

Fragile X syndrome (FXS) causes mental impairment and autism through transcriptional silencing of the Fmr1 gene, resulting in the loss of the RNA-binding protein fragile X mental retardation protein (FMRP). Cortical pyramidal neurons in affected individuals and Fmr1 knock-out (KO) mice have an increased density of dendritic spines. The mutant mice also show defects in synaptic and experience-dependent circuit plasticity, which are known to be mediated in part by dendritic spine dynamics. We used in vivo time-lapse imaging with two-photon microscopy through cranial windows in male and female neonatal mice to test the hypothesis that dynamics of dendritic protrusions are altered in KO mice during early postnatal development. We find that layer 2/3 neurons from wild-type mice exhibit a rapid decrease in dendritic spine dynamics during the first 2 postnatal weeks, as immature filopodia are replaced by mushroom spines. In contrast, KO mice show a developmental delay in the downregulation of spine turnover and in the transition from immature to mature spine subtypes. Blockade of metabotropic glutamate receptor (mGluR) signaling, which reverses some adult phenotypes of KO mice, accentuated this immature protrusion phenotype in KO mice. Thus, absence of FMRP delays spine stabilization and dysregulated mGluR signaling in FXS may partially normalize this early synaptic defect.

Selenium Status Alters the Immune Response and Expulsion of Adult Heligmosomoides bakeri Worms in Mice

PubMed Central

Cheung, Lumei; Beshah, Ethiopia; Shea-Donohue, Terez; Urban, Joseph F.

2013-01-01

Heligmosomoides bakeri is a nematode with parasitic development exclusively in the small intestine of infected mice that induces a potent STAT6-dependent Th2 immune response. We previously demonstrated that host protective expulsion of adult H. bakeri worms from a challenge infection was delayed in selenium (Se)-deficient mice. In order to explore mechanisms associated with the delayed expulsion, 3-week-old female BALB/c mice were placed on a torula yeast-based diet with or without 0.2 ppm Se, and after 5 weeks, they were inoculated with H. bakeri infective third-stage larvae (L3s). Two weeks after inoculation, the mice were treated with an anthelmintic and then rested, reinoculated with L3s, and evaluated at various times after reinoculation. Analysis of gene expression in parasite-induced cysts and surrounding tissue isolated from the intestine of infected mice showed that the local-tissue Th2 response was decreased in Se-deficient mice compared to that in Se-adequate mice. In addition, adult worms recovered from Se-deficient mice had higher ATP levels than worms from Se-adequate mice, indicating greater metabolic activity in the face of a suboptimal Se-dependent local immune response. Notably, the process of worm expulsion was restored within 2 to 4 days after feeding a Se-adequate diet to Se-deficient mice. Expulsion was associated with an increased local expression of Th2-associated genes in the small intestine, intestinal glutathione peroxidase activity, secreted Relm-β protein, anti-H. bakeri IgG1 production, and reduced worm fecundity and ATP-dependent metabolic activity. PMID:23649095

Prenatal and lactational exposure to low-doses of bisphenol A alters adult mice behavior.

PubMed

Nakamura, Keiko; Itoh, Kyoko; Dai, Hongmei; Han, Longzhe; Wang, Xiaohang; Kato, Shingo; Sugimoto, Tohru; Fushiki, Shinji

2012-01-01

Bisphenol A (BPA) is an endocrine-disrupting chemical, widely used in dentistry and various industries. We previously reported that BPA affected murine neocortical development by accelerating neuronal differentiation/migration, resulting in abnormal neocortical architecture as well as aberrant thalamocortical connections in the brains of adult mice. The aim of this study was to investigate whether prenatal and lactational BPA exposure affected behavior in adult mice. Pregnant mice were injected subcutaneously with 20μg/kg of BPA daily from embryonic day 0 (E0) until postnatal day 21 (P21). Control animals received a vehicle alone. Behavioral tests (n=15-20) were conducted at postnatal 3weeks (P3W) and P10-15W. After an open-field test, an elevated plus maze and Morris water maze tests were performed. The total distance in the elevated plus maze test at P3W and in the open-field test at P10W was significantly decreased in the BPA-exposed group, compared with the control group. Significant sex differences were observed in the time spent in the central area in the open-field test at P3W and in the total distance in the elevated plus maze test at P11W. These results indicated that prenatal and lactational BPA exposure disturbed the murine behavior in the postnatal development period and the adult mice. Copyright © 2011 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Altered Body Weight Regulation in CK1ε Null and tau Mutant Mice on Regular Chow and High Fat Diets

PubMed Central

Zhou, Lili; Summa, Keith C.; Olker, Christopher; Vitaterna, Martha H.; Turek, Fred W.

2016-01-01

Disruption of circadian rhythms results in metabolic dysfunction. Casein kinase 1 epsilon (CK1ε) is a canonical circadian clock gene. Null and tau mutations in CK1ε show distinct effects on circadian period. To investigate the role of CK1ε in body weight regulation under both regular chow (RC) and high fat (HF) diet conditions, we examined body weight on both RC and HF diets in CK1ε −/− and CK1ε tau/tau mice on a standard 24 hr light-dark (LD) cycle. Given the abnormal entrainment of CK1ε tau/tau mice on a 24 hr LD cycle, a separate set of CK1ε tau/tau mice were tested under both diet conditions on a 20 hr LD cycle, which more closely matches their endogenous period length. On the RC diet, both CK1ε −/− and CK1ε tau/tau mutants on a 24 hr LD cycle and CK1ε tau/tau mice on a 20 hr LD cycle exhibited significantly lower body weights, despite similar overall food intake and activity levels. On the HF diet, CK1ε tau/tau mice on a 20 hr LD cycle were protected against the development of HF diet-induced excess weight gain. These results provide additional evidence supporting a link between circadian rhythms and energy regulation at the genetic level, particularly highlighting CK1ε involved in the integration of circadian biology and metabolic physiology. PMID:27144030

Ablation of Neurons Expressing Melanin-Concentrating Hormone (MCH) in Adult Mice Improves Glucose Tolerance Independent of MCH Signaling

PubMed Central

Whiddon, Benjamin B.; Palmiter, Richard D.

2013-01-01

Melanin-concentrating hormone (MCH)-expressing neurons have been ascribed many roles based on tudies of MCH-deficient mice. However, MCH neurons express other neurotransmitters, including GABA, nesfatin, and cocaine–amphetamine-regulated transcript. The importance of these other signaling molecules made by MCH neurons remains incompletely characterized. To determine the roles of MCH neurons in vivo, we targeted expression of the human diphtheria toxin receptor (DTR) to the gene for MCH (Pmch). Within 2 weeks of diphtheria toxin injection, heterozygous PmchDTR/+ mice lost 98% of their MCH neurons. These mice became lean but ate normally and were hyperactive, especially during a fast. They also responded abnormally to psychostimulants. For these phenotypes, ablation of MCH neurons recapitulated knock-out of MCH, so MCH appears to be the critical neuromodulator released by these neurons. In contrast, MCH-neuron-ablated mice showed improved glucose tolerance when compared with MCH-deficient mutant mice and wild-type mice. We conclude that MCH neurons regulate glucose tolerance through signaling molecules other than MCH. PMID:23365238

Abnormal motor phenotype at adult stages in mice lacking type 2 deiodinase.

PubMed

Bárez-López, Soledad; Bosch-García, Daniel; Gómez-Andrés, David; Pulido-Valdeolivas, Irene; Montero-Pedrazuela, Ana; Obregon, Maria Jesus; Guadaño-Ferraz, Ana

2014-01-01

Thyroid hormones have a key role in both the developing and adult central nervous system and skeletal muscle. The thyroid gland produces mainly thyroxine (T4) but the intracellular concentrations of 3,5,3'-triiodothyronine (T3; the transcriptionally active hormone) in the central nervous system and skeletal muscle are modulated by the activity of type 2 deiodinase (D2). To date no neurological syndrome has been associated with mutations in the DIO2 gene and previous studies in young and juvenile D2-knockout mice (D2KO) did not find gross neurological alterations, possibly due to compensatory mechanisms. This study aims to analyze the motor phenotype of 3-and-6-month-old D2KO mice to evaluate the role of D2 on the motor system at adult stages in which compensatory mechanisms could have failed. Motor abilities were explored by validated tests. In the footprint test, D2KO showed an altered global gait pattern (mice walked slower, with shorter strides and with a hindlimb wider base of support than wild-type mice). No differences were detected in the balance beam test. However, a reduced latency to fall was found in the rotarod, coat-hanger and four limb hanging wire tests indicating impairment on coordination and prehensile reflex and a reduction of muscle strength. In histological analyses of cerebellum and skeletal muscle, D2KO mice did not present gross structural abnormalities. Thyroid hormones levels and deiodinases activities were also determined. In D2KO mice, despite euthyroid T3 and high T4 plasma levels, T3 levels were significantly reduced in cerebral cortex (48% reduction) and skeletal muscle (33% reduction), but not in the cerebellum where other deiodinase (type 1) is expressed. The motor alterations observed in D2KO mice indicate an important role for D2 in T3 availability to maintain motor function and muscle strength. Our results suggest a possible implication of D2 in motor disorders.

Abnormal Motor Phenotype at Adult Stages in Mice Lacking Type 2 Deiodinase

PubMed Central

Gómez-Andrés, David; Pulido-Valdeolivas, Irene; Montero-Pedrazuela, Ana; Obregon, Maria Jesus; Guadaño-Ferraz, Ana

2014-01-01

Background Thyroid hormones have a key role in both the developing and adult central nervous system and skeletal muscle. The thyroid gland produces mainly thyroxine (T4) but the intracellular concentrations of 3,5,3′-triiodothyronine (T3; the transcriptionally active hormone) in the central nervous system and skeletal muscle are modulated by the activity of type 2 deiodinase (D2). To date no neurological syndrome has been associated with mutations in the DIO2 gene and previous studies in young and juvenile D2-knockout mice (D2KO) did not find gross neurological alterations, possibly due to compensatory mechanisms. Aim This study aims to analyze the motor phenotype of 3-and-6-month-old D2KO mice to evaluate the role of D2 on the motor system at adult stages in which compensatory mechanisms could have failed. Results Motor abilities were explored by validated tests. In the footprint test, D2KO showed an altered global gait pattern (mice walked slower, with shorter strides and with a hindlimb wider base of support than wild-type mice). No differences were detected in the balance beam test. However, a reduced latency to fall was found in the rotarod, coat-hanger and four limb hanging wire tests indicating impairment on coordination and prehensile reflex and a reduction of muscle strength. In histological analyses of cerebellum and skeletal muscle, D2KO mice did not present gross structural abnormalities. Thyroid hormones levels and deiodinases activities were also determined. In D2KO mice, despite euthyroid T3 and high T4 plasma levels, T3 levels were significantly reduced in cerebral cortex (48% reduction) and skeletal muscle (33% reduction), but not in the cerebellum where other deiodinase (type 1) is expressed. Conclusions The motor alterations observed in D2KO mice indicate an important role for D2 in T3 availability to maintain motor function and muscle strength. Our results suggest a possible implication of D2 in motor disorders. PMID:25083788

Ross River virus mutant with a deletion in the E2 gene: properties of the virion, virus-specific macromolecule synthesis, and attenuation of virulence for mice.

PubMed

Vrati, S; Faragher, S G; Weir, R C; Dalgarno, L

1986-06-01

A mutant of RRV T48 the prototype strain of Ross River virus has been isolated with a 21-nucleotide deletion in the gene coding for the envelope glycoprotein E2. Direct sequencing of the 26 S subgenomic RNA, together with HaeIII and TaqI restriction digest analysis of cDNA to RNAs from cells infected with the mutant virus (RRV dE2) and with RRV T48, were consistent with the deletion being the only major alteration in the mutant genome. The E2 protein of RRV dE2 virions had a higher electrophoretic mobility than that of RRV T48 E2 protein. Neither RRV dE2 nor RRV T48 virions contained more than trace amounts of E3, the small envelope glycoprotein found in Semliki Forest virus. RRV dE2 generated small plaques on Vero cell monolayers; plaque formation was not temperature-sensitive between 32 and 41 degrees. By comparison with RRV T48 the infectivity of RRV dE2 virions was thermolabile at 50 degrees. In BHK cells RRV dE2 grew with similar kinetics to RRV T48. Rates of synthesis of 26 S RNA and 49 S RNA were higher in cells infected with RRV dE2 than in cells infected with RRV T48. Virus-specific protein synthesis and shut-down of host protein synthesis occurred 2-3 hr earlier in RRV dE2-infected cells than in cells infected with RRV T48. Minor differences between the two viruses were observed in the profiles of virus-specific proteins generated in infected cells. In day-old mice RRV dE2 induced less severe symptoms of hind leg paralysis than did RRV T48. A small increase in LD50 and average survival time was observed in RRV dE2-infected mice by comparison with RRV T48 infected mice. Peak titers reached by RRV dE2 in the hind leg muscle, brain, and blood of day-old mice were 3-4 log units less than the titers reached during infection with RRV T48. In week-old mice the differences in virulence between the two strains were magnified: RRV dE2 induced no detectable symptoms even when injected at high doses (8 X 10(6) PFU) whereas the LD50 and average survival time for RRV T

Fetal alcohol exposure disrupts metabolic signaling in hypothalamic proopiomelanocortin neurons via a circadian mechanism in male mice.

PubMed

Agapito, Maria A; Zhang, Changqing; Murugan, Sengottuvelan; Sarkar, Dipak K

2014-07-01

Early-life ethanol feeding (ELAF) alters the metabolic function of proopiomelanocortin (POMC)-producing neurons and the circadian expression of clock regulatory genes in the hypothalamus. We investigated whether the circadian mechanisms control the action of ELAF on metabolic signaling genes in POMC neurons. Gene expression measurements of Pomc and a selected group of metabolic signaling genes, Stat3, Sirt1, Pgc1-α, and Asb4 in laser-captured microdissected POMC neurons in the hypothalamus of POMC-enhanced green fluorescent protein mice showed circadian oscillations under light/dark and constant darkness conditions. Ethanol programmed these neurons such that the adult expression of Pomc, Stat3, Sirt, and Asb4 gene transcripts became arrhythmic. In addition, ELAF dampened the circadian peak of gene expression of Bmal1, Per1, and Per2 in POMC neurons. We crossed Per2 mutant mice with transgenic POMC-enhanced green fluorescent protein mice to determine the role of circadian mechanism in ELAF-altered metabolic signaling in POMC neurons. We found that ELAF failed to alter arrhythmic expression of most circadian genes, with the exception of the Bmal1 gene and metabolic signaling regulating genes in Per2 mutant mice. Comparison of the ELAF effects on the circadian blood glucose in wild-type and Per2 mutant mice revealed that ELAF dampened the circadian peak of glucose, whereas the Per2 mutation shifted the circadian cycle and prevented the ELAF dampening of the glucose peak. These data suggest the possibility that the Per2 gene mutation may regulate the ethanol actions on Pomc and the metabolic signaling genes in POMC neurons in the hypothalamus by blocking circadian mechanisms.

Growth restriction, leptin, and the programming of adult behavior in mice.

PubMed

Meyer, Lauritz R; Zhu, Vivian; Miller, Alise; Roghair, Robert D

2014-12-15

Prematurity and neonatal growth restriction (GR) are risk factors for autism and attention deficit hyperactivity disorder (ADHD). Leptin production is suppressed during periods of undernutrition, and we have shown that isolated neonatal leptin deficiency leads to adult hyperactivity while neonatal leptin supplementation normalizes the brain morphology of GR mice. We hypothesized that neonatal leptin would prevent the development of GR-associated behavioral abnormalities. From postnatal day 4-14, C57BL/6 mice were randomized to daily injections of saline or leptin (80ng/g), and GR was identified by a weanling weight below the tenth percentile. The behavioral phenotypes of GR and control mice were assessed beginning at 4 months. Within the tripartite chamber, GR mice had significantly impaired social interaction. Baseline escape times from the Barnes maze were faster for GR mice (65+/-6s vs 87+/-7s for controls, p<0.05), but GR mice exhibited regression in their escape times on days 2 and 3 (56% regressed vs 22% of control saline mice, p<0.05). Compared to controls, GR mice entered the open arms of the elevated plus maze more often and stayed there longer (72+/-10s vs 36+/-5s, p<0.01). Neonatal leptin supplementation normalized the behavior of GR mice across all behavioral assays. In conclusion, GR alters the social interactions, learning and activity of mice, and supplementation with the neurotrophic hormone leptin mitigates these effects. We speculate neonatal leptin deficiency may contribute to the adverse neurodevelopmental outcomes associated with postnatal growth restriction, and postnatal leptin therapy may be protective. Copyright © 2014 Elsevier B.V. All rights reserved.

Acute exposure to diesel exhaust impairs adult neurogenesis in mice: prominence in males and protective effect of pioglitazone.

PubMed

Coburn, Jacki L; Cole, Toby B; Dao, Khoi T; Costa, Lucio G

2018-05-01

Adult neurogenesis is the process by which neural stem cells give rise to new functional neurons in specific regions of the adult brain, a process that occurs throughout life. Significantly, neurodegenerative and psychiatric disorders present suppressed neurogenesis, activated microglia, and neuroinflammation. Traffic-related air pollution has been shown to adversely affect the central nervous system. As the cardinal effects of air pollution exposure are microglial activation, and ensuing oxidative stress and neuroinflammation, we investigated whether acute exposures to diesel exhaust (DE) would inhibit adult neurogenesis in mice. Mice were exposed for 6 h to DE at a PM 2.5 concentration of 250-300 μg/m 3 , followed by assessment of adult neurogenesis in the hippocampal subgranular zone (SGZ), the subventricular zone (SVZ), and olfactory bulb (OB). DE impaired cellular proliferation in the SGZ and SVZ in males, but not females. DE reduced adult neurogenesis, with male mice showing fewer new neurons in the SGZ, SVZ, and OB, and females showing fewer new neurons only in the OB. To assess whether blocking microglial activation protected against DE-induced suppression of adult hippocampal neurogenesis, male mice were pre-treated with pioglitazone (PGZ) prior to DE exposure. The effects of DE exposure on microglia, as well as neuroinflammation and oxidative stress, were reduced by PGZ. PGZ also antagonized DE-induced suppression of neurogenesis in the SGZ. These results suggest that DE exposure impairs adult neurogenesis in a sex-dependent manner, by a mechanism likely to involve microglia activation and neuroinflammation.

Inhibition of Shp2 suppresses mutant EGFR-induced lung tumors in transgenic mouse model of lung adenocarcinoma

PubMed Central

Schneeberger, Valentina E.; Ren, Yuan; Luetteke, Noreen; Huang, Qingling; Chen, Liwei; Lawrence, Harshani R.; Lawrence, Nicholas J.; Haura, Eric B.; Koomen, John M.; Coppola, Domenico; Wu, Jie

2015-01-01

Epidermal growth factor receptor (EGFR) mutants drive lung tumorigenesis and are targeted for therapy. However, resistance to EGFR inhibitors has been observed, in which the mutant EGFR remains active. Thus, it is important to uncover mediators of EGFR mutant-driven lung tumors to develop new treatment strategies. The protein tyrosine phosphatase (PTP) Shp2 mediates EGF signaling. Nevertheless, it is unclear if Shp2 is activated by oncogenic EGFR mutants in lung carcinoma or if inhibiting the Shp2 PTP activity can suppress EGFR mutant-induced lung adenocarcinoma. Here, we generated transgenic mice containing a doxycycline (Dox)-inducible PTP-defective Shp2 mutant (tetO-Shp2CSDA). Using the rat Clara cell secretory protein (CCSP)-rtTA-directed transgene expression in the type II lung pneumocytes of transgenic mice, we found that the Gab1-Shp2 pathway was activated by EGFRL858R in the lungs of transgenic mice. Consistently, the Gab1-Shp2 pathway was activated in human lung adenocarcinoma cells containing mutant EGFR. Importantly, Shp2CSDA inhibited EGFRL858R-induced lung adenocarcinoma in transgenic animals. Analysis of lung tissues showed that Shp2CSDA suppressed Gab1 tyrosine phosphorylation and Gab1-Shp2 association, suggesting that Shp2 modulates a positive feedback loop to regulate its own activity. These results show that inhibition of the Shp2 PTP activity impairs mutant EGFR signaling and suppresses EGFRL858R-driven lung adenocarcinoma. PMID:25730908

Individual differences in torpor expression in adult mice are related to relative birth weight.

PubMed

Kato, Goro A; Sakamoto, Shinsuke H; Eto, Takeshi; Okubo, Yoshinobu; Shinohara, Akio; Morita, Tetsuo; Koshimoto, Chihiro

2018-04-20

Daily torpor is a physiological adaptation in small mammals and birds, characterised by drastic reductions in metabolism and body temperature. Energy-constraining conditions, such as cold and starvation, are known to cause the expression of daily torpor. However, the reason for high degrees of inter- and intra- individual variation in torpor expression (TE) in similar situations is not clear. As littermates of altricial animals are exposed to an uneven allocation of maternal resources from conception to weaning, we tested whether early nutritional experiences have long-term effects on TE in adults. We used full-sibling littermates of laboratory mice that as adults were starved overnight to induce torpor. We measured body weight from birth until adulthood as an indicator of nutritional status, and calculated the relative body weight (RBW) as an indicator of the difference in nutritional status within a litter. After maturation, we subjected mice to five repeated torpor induction trials involving 24 hours of fasting and 5 days of recovery. Half of the female mice displayed great individual variation in TE, whereas male mice rarely exhibited daily torpor. In females, RBW at birth influenced TE, irrespective of body weight in adulthood; thus, female mice born with low RBWs displayed high TE in adulthood. In conclusion, we provide evidence that TE in mice differs among littermates, and that this variation is linked closely to heterogeneous nutritional experiences during the foetal period. © 2018. Published by The Company of Biologists Ltd.

Autism-Relevant Social Abnormalities and Cognitive Deficits in Engrailed-2 Knockout Mice

PubMed Central

Brielmaier, Jennifer; Matteson, Paul G.; Silverman, Jill L.; Senerth, Julia M.; Kelly, Samantha; Genestine, Matthieu; Millonig, James H.

2012-01-01

ENGRAILED 2 (En2), a homeobox transcription factor, functions as a patterning gene in the early development and connectivity of rodent hindbrain and cerebellum, and regulates neurogenesis and development of monoaminergic pathways. To further understand the neurobiological functions of En2, we conducted neuroanatomical expression profiling of En2 wildtype mice. RTQPCR assays demonstrated that En2 is expressed in adult brain structures including the somatosensory cortex, hippocampus, striatum, thalamus, hypothalamus and brainstem. Human genetic studies indicate that EN2 is associated with autism. To determine the consequences of En2 mutations on mouse behaviors, including outcomes potentially relevant to autism, we conducted comprehensive phenotyping of social, communication, repetitive, and cognitive behaviors. En2 null mutants exhibited robust deficits in reciprocal social interactions as juveniles and adults, and absence of sociability in adults, replicated in two independent cohorts. Fear conditioning and water maze learning were impaired in En2 null mutants. High immobility in the forced swim test, reduced prepulse inhibition, mild motor coordination impairments and reduced grip strength were detected in En2 null mutants. No genotype differences were found on measures of ultrasonic vocalizations in social contexts, and no stereotyped or repetitive behaviors were observed. Developmental milestones, general health, olfactory abilities, exploratory locomotor activity, anxiety-like behaviors and pain responses did not differ across genotypes, indicating that the behavioral abnormalities detected in En2 null mutants were not attributable to physical or procedural confounds. Our findings provide new insight into the role of En2 in complex behaviors and suggest that disturbances in En2 signaling may contribute to neuropsychiatric disorders marked by social and cognitive deficits, including autism spectrum disorders. PMID:22829897

Intraflagellar transporter protein (IFT27), an IFT25 binding partner, is essential for male fertility and spermiogenesis in mice.

PubMed

Zhang, Yong; Liu, Hong; Li, Wei; Zhang, Zhengang; Shang, Xuejun; Zhang, David; Li, Yuhong; Zhang, Shiyang; Liu, Junpin; Hess, Rex A; Pazour, Gregory J; Zhang, Zhibing

2017-12-01

Intraflagellar transport (IFT) is an evolutionarily conserved mechanism essential for the assembly and maintenance of most eukaryotic cilia and flagella. In mice, mutations in IFT proteins have been shown to cause several ciliopathies including retinal degeneration, polycystic kidney disease, and hearing loss. However, little is known about its role in the formation of the sperm tail, which has the longest flagella of mammalian cells. IFT27 is a component of IFT-B complex and binds to IFT25 directly. In mice, IFT27 is highly expressed in the testis. To investigate the role of IFT27 in male germ cells, the floxed Ift27 mice were bred with Stra8-iCre mice so that the Ift27 gene was disrupted in spermatocytes/spermatids. The Ift27: Stra8-iCre mutant mice did not show any gross abnormalities, and all of the mutant mice survived to adulthood. There was no difference between testis weight/body weight between controls and mutant mice. All adult homozygous mutant males examined were completely infertile. Histological examination of the testes revealed abnormally developed germ cells during the spermiogenesis phase. The epididymides contained round bodies of cytoplasm. Sperm number was significantly reduced compared to the controls and only about 2% of them remained significantly reduced motility. Examination of epididymal sperm by light microscopy and SEM revealed multiple morphological abnormalities including round heads, short and bent tails, abnormal thickness of sperm tails in some areas, and swollen tail tips in some sperm. TEM examination of epididymal sperm showed that most sperm lost the "9+2″ axoneme structure, and the mitochondria sheath, fibrous sheath, and outer dense fibers were also disorganized. Some sperm flagella also lost cell membrane. Levels of IFT25 and IFT81 were significantly reduced in the testis of the conditional Ift27 knockout mice, and levels of IFT20, IFT74, and IFT140 were not changed. Sperm lipid rafts, which were disrupted in the

Intraflagellar Transporter Protein (IFT27), an IFT25 binding partner, Is Essential For Male Fertility and Spermiogenesis In Mice

PubMed Central

Zhang, Yong; Liu, Hong; Li, Wei; Zhang, Zhengang; Shang, Xuejun; Zhang, David; Li, Yuhong; Zhang, Shiyang; Liu, Junpin; Hess, Rex A; Pazour, Gregory J; Zhang, Zhibing

2017-01-01

Intraflagellar transport (IFT) is an evolutionarily conserved mechanism essential for the assembly and maintenance of most eukaryotic cilia and flagella. In mice, mutations in IFT proteins have been shown to cause several ciliopathies including retinal degeneration, polycystic kidney disease, and hearing loss. However, little is known about its role in the formation of the sperm tail, which has the longest flagella of mammalian cells. IFT27 is a component of IFT-B complex and binds to IFT25 directly. In mice, IFT27 is highly expressed in the testis. To investigate the role of IFT27 in male germ cells, the floxed Ift27 mice were bred with Stra8-iCre mice so that the Ift27 gene was disrupted in spermatocytes/spermatids. The Ift27:Stra8-iCre mutant mice did not show any gross abnormalities, and all of the mutant mice survive to adulthood. There was no difference between testis weight/body weight between controls and mutant mice. All adult homozygous mutant males examined were completely infertile. Histological examination of the testes revealed abnormally developed germ cells during the spermiogenesis phase. The epididymis contained round bodies of cytoplasm. Sperm number was significantly reduced compared to the controls and only about 2% of them remained significantly reduced motility. Examination of epididymal sperm by light microscopy and SEM revealed multiple morphological abnormalities including round heads, short and bent tails, abnormal thickness of sperm tails in some areas, and swollen tail tips in some sperm. TEM examination of epididymal sperm showed that most sperm lost the “9+2” axoneme structure, and the mitochondria sheath, fibrous sheath, and outer dense fibers were also disorganized. Some sperm flagella also lost cell membrane. Levels of IFT25 and IFT81 were significantly reduced in the testis of the conditional Ift27 knockout mice, and levels of IFT20, IFT74, and IFT140 were not changed. Sperm lipid rafts, which were disrupted in the conditional

Radiation Exposure Enhances Hepatocyte Proliferation in Neonatal Mice but not in Adult Mice.

PubMed

Shang, Yi; Sawa, Yurika; Blyth, Benjamin J; Tsuruoka, Chizuru; Nogawa, Hiroyuki; Shimada, Yoshiya; Kakinuma, Shizuko

2017-08-01

There is a natural tendency to expect that irradiation of an infant organ prior to development-related expansion will result in a higher risk of developing cancer than that of fully-developed adult tissue, and this has generally been observed. However, if tissues also vary in their initial responses to radiation depending on age, the interplay between tissue- and age-dependent risk would potentially be quite complex. We have previously shown opposing age-dependent induction of apoptosis for the intestinal epithelium and hematopoietic cells in mice, but such data are not yet available for the liver. Here, we have examined markers of DNA damage, initiation of DNA damage responses, cell cycle arrest, apoptosis and proliferation, as well as gene expression, in the B6C3F1 mouse liver over the hours and days after irradiation of mice at 1 or 7 weeks of age. We found that induction and resolution of radiation-induced DNA damage is not accompanied by significant changes in these cellular end points in the adult liver, while in infant hepatocytes modest induction of p53 accumulation and p21-mediated cell cycle arrest in a small fraction of damaged cells was overshadowed by a further stimulation of proliferation over the relatively high levels already found in the neonatal liver. We observed distinct expression of genes that regulate cell division between the ages, which may contribute to the differential responses. These data suggest that the growth factor signaling environment of the infant liver may mediate radiation-induced proliferation and increased liver cancer risk after irradiation during early life.

Liver tumor formation by a mutant retinoblastoma protein in the transgenic mice is caused by an upregulation of c-Myc target genes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Bo; Hikosaka, Keisuke; Sultana, Nishat

2012-01-06

Highlights: Black-Right-Pointing-Pointer Fifty percent of the mutant Rb transgenic mice produced liver tumors. Black-Right-Pointing-Pointer In the tumor, Foxm1, Skp2, Bmi1 and AP-1 mRNAs were up-regulated. Black-Right-Pointing-Pointer No increase in expression of the Myc-target genes was observed in the non-tumorous liver. Black-Right-Pointing-Pointer Tumor formation depends on up-regulation of the Myc-target genes. -- Abstract: The retinoblastoma (Rb) tumor suppressor encodes a nuclear phosphoprotein that regulates cellular proliferation, apoptosis and differentiation. In order to adapt itself to these biological functions, Rb is subjected to modification cycle, phosphorylation and dephosphorylation. To directly determine the effect of phosphorylation-resistant Rb on liver development and function, wemore » generated transgenic mice expressing phosphorylation-resistant human mutant Rb (mt-Rb) under the control of the rat hepatocyte nuclear factor-1 gene promoter/enhancer. Expression of mt-Rb in the liver resulted in macroscopic neoplastic nodules (adenomas) with {approx}50% incidence within 15 months old. Interestingly, quantitative reverse transcriptase-PCR analysis showed that c-Myc was up-regulated in the liver of mt-Rb transgenic mice irrespective of having tumor tissues or no tumor. In tumor tissues, several c-Myc target genes, Foxm1, c-Jun, c-Fos, Bmi1 and Skp2, were also up-regulated dramatically. We determined whether mt-Rb activated the Myc promoter in the HTP9 cells and demonstrated that mt-Rb acted as an inhibitor of wild-type Rb-induced repression on the Myc promoter. Our results suggest that continued upregulation of c-Myc target genes promotes the liver tumor formation after about 1 year of age.« less

In vivo cell-autonomous transcriptional abnormalities revealed in mice expressing mutant huntingtin in striatal but not cortical neurons.

PubMed

Thomas, Elizabeth A; Coppola, Giovanni; Tang, Bin; Kuhn, Alexandre; Kim, SoongHo; Geschwind, Daniel H; Brown, Timothy B; Luthi-Carter, Ruth; Ehrlich, Michelle E

2011-03-15

Huntington's disease (HD), caused by a CAG repeat expansion in the huntingtin (HTT) gene, is characterized by abnormal protein aggregates and motor and cognitive dysfunction. Htt protein is ubiquitously expressed, but the striatal medium spiny neuron (MSN) is most susceptible to dysfunction and death. Abnormal gene expression represents a core pathogenic feature of HD, but the relative roles of cell-autonomous and non-cell-autonomous effects on transcription remain unclear. To determine the extent of cell-autonomous dysregulation in the striatum in vivo, we examined genome-wide RNA expression in symptomatic D9-N171-98Q (a.k.a. DE5) transgenic mice in which the forebrain expression of the first 171 amino acids of human Htt with a 98Q repeat expansion is limited to MSNs. Microarray data generated from these mice were compared with those generated on the identical array platform from a pan-neuronal HD mouse model, R6/2, carrying two different CAG repeat lengths, and a relatively high degree of overlap of changes in gene expression was revealed. We further focused on known canonical pathways associated with excitotoxicity, oxidative stress, mitochondrial dysfunction, dopamine signaling and trophic support. While genes related to excitotoxicity, dopamine signaling and trophic support were altered in both DE5 and R6/2 mice, which may be either cell autonomous or non-cell autonomous, genes related to mitochondrial dysfunction, oxidative stress and the peroxisome proliferator-activated receptor are primarily affected in DE5 transgenic mice, indicating cell-autonomous mechanisms. Overall, HD-induced dysregulation of the striatal transcriptome can be largely attributed to intrinsic effects of mutant Htt, in the absence of expression in cortical neurons.

Bidirectional modulation of fear extinction by mediodorsal thalamic firing in mice.

PubMed

Lee, Sukchan; Ahmed, Touqeer; Lee, Soojung; Kim, Huisu; Choi, Sukwoo; Kim, Duk-Soo; Kim, Sang Jeong; Cho, Jeiwon; Shin, Hee-Sup

2011-12-25

The mediodorsal thalamic nucleus has been implicated in the control of memory processes. However, the underlying neural mechanism remains unclear. Here we provide evidence for bidirectional modulation of fear extinction by the mediodorsal thalamic nucleus. Mice with a knockout or mediodorsal thalamic nucleus-specific knockdown of phospholipase C β4 exhibited impaired fear extinction. Mutant mediodorsal thalamic nucleus neurons in slices showed enhanced burst firing accompanied by increased T-type Ca(2+) currents; blocking of T channels in vivo rescued the fear extinction. Tetrode recordings in freely moving mice revealed that, during extinction, the single-spike (tonic) frequency of mediodorsal thalamic nucleus neurons increased in wild-type mice, but was static in mutant mice. Furthermore, tonic-evoking microstimulations of the mediodorsal thalamic nucleus, contemporaneous with the extinction tones, rescued fear extinction in mutant mice and facilitated it in wild-type mice. In contrast, burst-evoking microstimulation suppressed extinction in wild-type mice, mimicking the mutation. These results suggest that the firing mode of the mediodorsal thalamic nucleus is critical for the modulation of fear extinction.

Juvenile manifestation of ultrasound communication deficits in the neuroligin-4 null mutant mouse model of autism.

PubMed

Ju, Anes; Hammerschmidt, Kurt; Tantra, Martesa; Krueger, Dilja; Brose, Nils; Ehrenreich, Hannelore

2014-08-15

Neuroligin-4 (Nlgn4) is a member of the neuroligin family of postsynaptic cell adhesion molecules. Loss-of-function mutations of NLGN4 are among the most frequent, known genetic causes of heritable autism. Adult Nlgn4 null mutant (Nlgn4(-/-)) mice are a construct valid model of human autism, with both genders displaying a remarkable autistic phenotype, including deficits in social interaction and communication as well as restricted and repetitive behaviors. In contrast to adults, autism-related abnormalities in neonatal and juvenile Nlgn4(-/-) mice have not been reported yet. The present study has been designed to systematically investigate in male and female Nlgn4(-/-) pups versus wildtype littermates (WT, Nlgn4(+/+)) developmental milestones and stimulus-induced ultrasound vocalization (USV). Neonatal development, followed daily from postnatal days (PND) 4 to 21, including physical development, neurological reflexes and neuromotor coordination, did not yield any differences between Nlgn4(-/-) and their WT littermates. USV in pups (PND8-9) in response to brief separation from their mothers revealed remarkable gender effects, and a genotype influence in females regarding latency to first call. In juveniles (PND22-23), USV monitoring upon exposure to an anesthetized female intruder mouse uncovered a clear genotype effect with reduced USV in Nlgn4(-/-) mice, and again a more prominent phenotype in females. Together, these data support an early manifestation of communication deficits in Nlgn4(-/-) mice that appear more pronounced in immature females with their overall stronger USV as compared to males. Copyright © 2014 Elsevier B.V. All rights reserved.

Plasmodium yoelii: induction of attenuated mutants by irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waki, S.; Yonome, I.; Suzuki, M.

When erythrocytic forms of Plasmodium yoelii nigeriensis, which is invariably fatal in mice, were exposed to X rays, the dose to reduce surviving parasites to one millionth was 100 gray (10 Krad). A suspension of 5 X 10(6) per ml of parasitized erythrocyte was irradiated at 100 gray, and 0.2 ml aliquots were inoculated into 22 mice. Eleven mice showed patent parasitemia, and in these the growth curves were less steep than that found in nonirradiated parasites. The infections of 8 mice of the 11 were self-resolving, and the attenuated feature of the parasites maintained following a limited number ofmore » blood passages. The parasites were slowly growing even in nude mice and cause self-resolving infections in intact mice. BALB/c mice immunized with the attenuated parasites were protected against subsequent challenge infections with the original virulent erythrocytic and sporogonic forms. These findings indicate that attenuated mutants of malaria parasites can be readily induced by this method.« less

Mutations in the Schmallenberg Virus Gc Glycoprotein Facilitate Cellular Protein Synthesis Shutoff and Restore Pathogenicity of NSs Deletion Mutants in Mice.

PubMed

Varela, Mariana; Pinto, Rute Maria; Caporale, Marco; Piras, Ilaria M; Taggart, Aislynn; Seehusen, Frauke; Hahn, Kerstin; Janowicz, Anna; de Souza, William Marciel; Baumgärtner, Wolfgang; Shi, Xiaohong; Palmarini, Massimo

2016-06-01

Serial passage of viruses in cell culture has been traditionally used to attenuate virulence and identify determinants of viral pathogenesis. In a previous study, we found that a strain of Schmallenberg virus (SBV) serially passaged in tissue culture (termed SBVp32) unexpectedly displayed increased pathogenicity in suckling mice compared to wild-type SBV. In this study, we mapped the determinants of SBVp32 virulence to the viral genome M segment. SBVp32 virulence is associated with the capacity of this virus to reach high titers in the brains of experimentally infected suckling mice. We also found that the Gc glycoprotein, encoded by the M segment of SBVp32, facilitates host cell protein shutoff in vitro Interestingly, while the M segment of SBVp32 is a virulence factor, we found that the S segment of the same virus confers by itself an attenuated phenotype to wild-type SBV, as it has lost the ability to block the innate immune system of the host. Single mutations present in the Gc glycoprotein of SBVp32 are sufficient to compensate for both the attenuated phenotype of the SBVp32 S segment and the attenuated phenotype of NSs deletion mutants. Our data also indicate that the SBVp32 M segment does not act as an interferon (IFN) antagonist. Therefore, SBV mutants can retain pathogenicity even when they are unable to fully control the production of IFN by infected cells. Overall, this study suggests that the viral glycoprotein of orthobunyaviruses can compensate, at least in part, for the function of NSs. In addition, we also provide evidence that the induction of total cellular protein shutoff by SBV is determined by multiple viral proteins, while the ability to control the production of IFN maps to the NSs protein. The identification of viral determinants of pathogenesis is key to the development of prophylactic and intervention measures. In this study, we found that the bunyavirus Gc glycoprotein is a virulence factor. Importantly, we show that mutations in the Gc

Immunization with a novel Clostridium perfringens epsilon toxin mutant rETX(Y196E)-C confers strong protection in mice.

PubMed

Yao, Wenwu; Kang, Jingjing; Kang, Lin; Gao, Shan; Yang, Hao; Ji, Bin; Li, Ping; Liu, Jing; Xin, Wenwen; Wang, Jinglin

2016-04-06

Epsilon toxin (ETX) is produced by toxinotypes B and D of Clostridium perfringens. It can induce lethal enterotoxemia in domestic animals, mainly in sheep, goats and cattle, causing serious economic losses to global animal husbandry. In this study, a novel and stable epsilon toxin mutant rETX(Y196E)-C, obtained by substituting the 196th tyrosine (Y196) with glutamic acid (E) and introducing of 23 amino acids long C-terminal peptide, was determined as a promising recombinant vaccine candidate against enterotoxemia. After the third vaccination, the antibody titers against recombinant wild type (rETX) could reach 1:10(5) in each immunized group, and the mice were completely protected from 100 × LD50 (50% lethal dose) of rETX challenge. The mice in 15 μg subcutaneously immunized group fully survived at the dose of 500 × LD50 of rETX challenge and 80% of mice survived at 180 μg (1000 × LD50) of rETX administration. In vitro, immune sera from 15 μg subcutaneously immunized group could completely protect MDCK cells from 16 × CT50 (50% lethal dose of cells) of rETX challenge and protect against 10 × LD50 dose (1.8 μg) of rETX challenge in mice. These data suggest that recombinant protein rETX(Y196E)-C is a potential vaccine candidate for future applied researches.

Heterozygous Vangl2Looptail mice reveal novel roles for the planar cell polarity pathway in adult lung homeostasis and repair

PubMed Central

Poobalasingam, Thanushiyan; Yates, Laura L.; Walker, Simone A.; Pereira, Miguel; Gross, Nina Y.; Ali, Akmol; Kolatsi-Joannou, Maria; Jarvelin, Marjo-Riitta; Pekkanen, Juha; Papakrivopoulou, Eugenia; Long, David A.; Griffiths, Mark; Wagner, Darcy; Königshoff, Melanie; Hind, Matthew; Minelli, Cosetta; Lloyd, Clare M.

2017-01-01

ABSTRACT Lung diseases impose a huge economic and health burden worldwide. A key aspect of several adult lung diseases, such as idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD), including emphysema, is aberrant tissue repair, which leads to an accumulation of damage and impaired respiratory function. Currently, there are few effective treatments available for these diseases and their incidence is rising. The planar cell polarity (PCP) pathway is critical for the embryonic development of many organs, including kidney and lung. We have previously shown that perturbation of the PCP pathway impairs tissue morphogenesis, which disrupts the number and shape of epithelial tubes formed within these organs during embryogenesis. However, very little is known about the role of the PCP pathway beyond birth, partly because of the perinatal lethality of many PCP mouse mutant lines. Here, we investigate heterozygous Looptail (Lp) mice, in which a single copy of the core PCP gene, Vangl2, is disrupted. We show that these mice are viable but display severe airspace enlargement and impaired adult lung function. Underlying these defects, we find that Vangl2Lp/+ lungs exhibit altered distribution of actin microfilaments and abnormal regulation of the actin-modifying protein cofilin. In addition, we show that Vangl2Lp/+ lungs exhibit many of the hallmarks of tissue damage, including an altered macrophage population, abnormal elastin deposition and elevated levels of the elastin-modifying enzyme, Mmp12, all of which are observed in emphysema. In vitro, disruption of VANGL2 impairs directed cell migration and reduces the rate of repair following scratch wounding of human alveolar epithelial cells. Moreover, using population data from a birth cohort of young adults, all aged 31, we found evidence of an interactive effect between VANGL2 and smoking on lung function. Finally, we show that PCP genes VANGL2 and SCRIB are significantly downregulated in lung

Acute social defeat stress increases the conditioned rewarding effects of cocaine in adult but not in adolescent mice.

PubMed

Montagud-Romero, S; Aguilar, M A; Maldonado, C; Manzanedo, C; Miñarro, J; Rodríguez-Arias, M

2015-08-01

Stressful experiences modify activity in areas of the brain involved in the rewarding effects of psychostimulants. In the present study we evaluated the influence of acute social defeat (ASD) on the conditioned rewarding effects of cocaine in adolescent (PND 29-32) and adult (PND 50-53) male mice in the conditioned place preference (CPP) paradigm. Experimental mice were exposed to social defeat in an agonistic encounter before each session of conditioning with 1mg/kg or 25mg/kg of cocaine. The effects of social defeat on corticosterone levels were also evaluated. Adult mice exposed to ASD showed an increase in the conditioned reinforcing effects of cocaine. Only these mice developed cocaine-induced CPP with the subthreshold dose of cocaine, and they needed a higher number of extinction sessions for the 25mg/kg cocaine-induced CPP to be extinguished. In adolescent mice, on the other hand, ASD reduced the conditioned reinforcing effects of cocaine, since CPP was not produced with the lower dose of cocaine and was extinguished faster when they were conditioned with 25mg/kg. Adult mice exposed to social defeat displayed higher levels of corticosterone than their controls and adolescent mice. Our results confirm that the effect of social defeat stress on the acquisition and reinstatement of the CPP induced by cocaine varies depending on the age at which this stress is experienced. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of electrocardiogram intervals during growth of FVB/N neonate mice

PubMed Central

2010-01-01

Background Electrocardiography remains the best diagnostic tool and therapeutic biomarker for a spectrum of pediatric diseases involving cardiac or autonomic nervous system defects. As genetic links to these disorders are established and transgenic mouse models produced in efforts to understand and treat them, there is a surprising lack of information on electrocardiograms (ECGs) and ECG abnormalities in neonate mice. This is likely due to the trauma and anaesthesia required of many legacy approaches to ECG recording in mice, exacerbated by the fragility of many mutant neonates. Here, we use a non-invasive system to characterize development of the heart rate and electrocardiogram throughout the growth of conscious neonate FVB/N mice. Results We examine ECG waveforms as early as two days after birth. At this point males and females demonstrate comparable heart rates that are 50% lower than adult mice. Neonatal mice exhibit very low heart rate variability. Within 12 days of birth PR, QRS and QTc interval durations are near adult values while heart rate continues to increase until weaning. Upon weaning FVB/N females quickly develop slower heart rates than males, though PR intervals are comparable between sexes until a later age. This suggests separate developmental events may contribute to these gender differences in electrocardiography. Conclusions We provide insight with a new level of detail to the natural course of heart rate establishment in neonate mice. ECG can now be conveniently and repeatedly used in neonatal mice. This should serve to be of broad utility, facilitating further investigations into development of a diverse group of diseases and therapeutics in preclinical mouse studies. PMID:20735846

Salt restriction induces pseudohypoaldosteronism type 1 in mice expressing low levels of the β-subunit of the amiloride-sensitive epithelial sodium channel

PubMed Central

Pradervand, Sylvain; Barker, Pierre M.; Wang, Qing; Ernst, Stephen A.; Beermann, Friedrich; Grubb, Barbara R.; Burnier, Michel; Schmidt, Andrea; Bindels, Rene J. M.; Gatzy, John T.; Rossier, Bernard C.; Hummler, Edith

1999-01-01

The amiloride-sensitive epithelial sodium channel (ENaC) is a heteromultimer of three homologous subunits (α-, β-, and γ-subunits). To study the role of the β-subunit in vivo, we analyzed mice in which the βENaC gene locus was disrupted. These mice showed low levels of βENaC mRNA expression in kidney (≈1%), lung (≈1%), and colon (≈4%). In homozygous mutant βENaC mice, no βENaC protein could be detected with immunofluorescent staining. At birth, there was a small delay in lung-liquid clearance that paralleled diminished amiloride-sensitive Na+ absorption in tracheal explants. With normal salt intake, these mice showed a normal growth rate. However, in vivo, adult βENaC m/m mice exhibited a significantly reduced ENaC activity in colon and elevated plasma aldosterone levels, suggesting hypovolemia and pseudohypoaldosteronism type 1. This phenotype was clinically silent, as βENaC m/m mice showed no weight loss, normal plasma Na+ and K+ concentrations, normal blood pressure, and a compensated metabolic acidosis. On low-salt diets, βENaC-mutant mice developed clinical symptoms of an acute pseudohypoaldosteronism type 1 (weight loss, hyperkalemia, and decreased blood pressure), indicating that βENaC is required for Na+ conservation during salt deprivation. PMID:9990093

Salmonella DNA Adenine Methylase Mutants Confer Cross-Protective Immunity

PubMed Central

Heithoff, Douglas M.; Enioutina, Elena Y.; Daynes, Raymond A.; Sinsheimer, Robert L.; Low, David A.; Mahan, Michael J.

2001-01-01

Salmonella isolates that lack or overproduce DNA adenine methylase (Dam) elicited a cross-protective immune response to different Salmonella serovars. The protection afforded by the Salmonella enterica serovar Typhimurium Dam vaccine was greater than that elicited in mice that survived a virulent infection. S. enterica serovar Typhimurium Dam mutant strains exhibited enhanced sensitivity to mediators of innate immunity such as antimicrobial peptides, bile salts, and hydrogen peroxide. Also, S. enterica serovar Typhimurium Dam− vaccines were not immunosuppressive; unlike wild-type vaccines, they failed to induce increased nitric oxide levels and permitted a subsequent robust humoral response to diptheria toxoid antigen in infected mice. Dam mutant strains exhibited a low-grade persistence which, coupled with the nonimmunosuppression and the ectopic protein expression caused by altered levels of Dam, may provide an expanded source of potential antigens in vaccinated hosts. PMID:11598044

Immunization with mutant HPV16 E7 protein inhibits the growth of TC-1 cells in tumor-bearing mice.

PubMed

Li, Yan-Li; Ma, Zhong-Liang; Zhao, Yue; Zhang, Jing

2015-04-01

Two human papillomavirus (HPV) 16 oncogenic proteins, E6 and E7, are co-expressed in the majority of HPV16-induced cervical cancer cells. Thus, the E6 and E7 proteins are good targets for developing therapeutic vaccines for cervical cancer. In the present study, immunization with the mutant non-transforming HPV16 E7 (mE7) protein was demonstrated to inhibit the growth of TC-1 cells in the TC-1 mouse model. The HPV16 mE7 gene was amplified by splicing overlap extension polymerase chain reaction using pET-28a(+)-E7 as a template, and the gene was cloned into pET-28a(+) to form pET-28a(+)-mE7. Compared with the E7 protein, mE7 lacks amino acid residues 94-98, and at residue 24, there is a Cys to Gly substitution. pET-28a(+)-mE7 was then introduced into Escherichia coli Rosetta. The expression of mE7 was induced by isopropyl β-D-1-thiogalactopyranoside. The mE7 protein was purified using Ni-NTA agarose and detected by SDS-PAGE and western blot analysis. In the tumor prevention model, no tumor was detected in the mice vaccinated with the mE7 protein. After 40 days, the tumor-free mice and control mice were challenged with 2×10 5 TC-1 cells. All control mice developed tumors six days later, but mE7 immunized mice were tumor free until 90 days. In the tumor therapy model, the TC-1 cells were initially injected subcutaneously, and the mice were subsequently vaccinated. Vaccination against the mE7 protein may significantly inhibit TC-1 cell growth compared to the control. These results demonstrated that immunization with the HPV16 mE7 protein elicited a long-term protective immunity against TC-1 tumor growth and generated a significant inhibition of TC-1 growth in a TC-1 mouse model.

Functional role of connexin43 gap junction channels in adult mouse heart assessed by inducible gene deletion.

PubMed

Eckardt, D; Theis, M; Degen, J; Ott, T; van Rijen, H V M; Kirchhoff, S; Kim, J-S; de Bakker, J M T; Willecke, K

2004-01-01

The gap junction protein Connexin43 (Cx43) is expressed in various cell types during embryonic development and in adult mice. Cx43 null mice (Cx43-/-) die perinatally due to cardiac malformation. In order to define the major functional role of Cx43 gap junction channels in adult mice and to circumvent perinatal death as well as direct or indirect compensation of Cx43 deficiency during development, we established a novel conditional Cx43 mouse mutant. To ablate Cx43 in adult mice in all cells that express Cx43 at a certain time, we targeted the 4-hydroxytamoxifen inducible Cre recombinase, Cre-ER(T), into the endogenous Cx43 locus. This approach left only one Cx43 coding region to be deleted upon induction of Cre-ER(T) activity. Highly efficient inducible ablation of Cx43 was shown in an embryonic stem cell test system and in adult mice. Although Cx43 protein was decreased in different tissues after induction of Cre-ER(T)-mediated recombination, cardiac abnormalities most likely account for death of those mice. Surface and telemetric ECG recordings revealed significant delay of ventricular activation and death during periods of bradyarrhythmia preceded by tachycardias. This novel approach of inducible ablation of Cx43 highlights the functional importance of normal activation of ventricular cardiomyocytes mediated by Cx43 gap junction channels in adult mouse heart to prevent initiation of fatal arrhythmias. The new mouse model should be useful for further analyses of molecular changes initiated by acute loss of Cx43 expression in various cell types.

Contrasting skeletal phenotypes in mice with an identical mutation targeted to thyroid hormone receptor alpha1 or beta.

PubMed

O'Shea, Patrick J; Bassett, J H Duncan; Sriskantharajah, Srividya; Ying, Hao; Cheng, Sheue-yann; Williams, Graham R

2005-12-01

Thyroid hormone (T(3)) regulates bone turnover and mineralization in adults and is essential for skeletal development. Surprisingly, we identified a phenotype of skeletal thyrotoxicosis in T(3) receptor beta(PV) (TRbeta(PV)) mice in which a targeted frameshift mutation in TRbeta results in resistance to thyroid hormone. To characterize mechanisms underlying thyroid hormone action in bone, we analyzed skeletal development in TRalpha1(PV) mice in which the same PV mutation was targeted to TRalpha1. In contrast to TRbeta(PV) mice, TRalpha1(PV) mutants exhibited skeletal hypothyroidism with delayed endochondral and intramembranous ossification, severe postnatal growth retardation, diminished trabecular bone mineralization, reduced cortical bone deposition, and delayed closure of the skull sutures. Skeletal hypothyroidism in TRalpha1(PV) mutants was accompanied by impaired GH receptor and IGF-I receptor expression and signaling in the growth plate, whereas GH receptor and IGF-I receptor expression and signaling were increased in TRbeta(PV) mice. These data indicate that GH receptor and IGF-I receptor are physiological targets for T(3) action in bone in vivo. The divergent phenotypes observed in TRalpha1(PV) and TRbeta(PV) mice arise because the pituitary gland is a TRbeta-responsive tissue, whereas bone is TRalpha responsive. These studies provide a new understanding of the complex relationship between central and peripheral thyroid status.

Mutant TDP-43 within motor neurons drives disease onset but not progression in amyotrophic lateral sclerosis.

PubMed

Ditsworth, Dara; Maldonado, Marcus; McAlonis-Downes, Melissa; Sun, Shuying; Seelman, Amanda; Drenner, Kevin; Arnold, Eveline; Ling, Shuo-Chien; Pizzo, Donald; Ravits, John; Cleveland, Don W; Da Cruz, Sandrine

2017-06-01

Mutations in TDP-43 cause amyotrophic lateral sclerosis (ALS), a fatal paralytic disease characterized by degeneration and premature death of motor neurons. The contribution of mutant TDP-43-mediated damage within motor neurons was evaluated using mice expressing a conditional allele of an ALS-causing TDP-43 mutant (Q331K) whose broad expression throughout the central nervous system mimics endogenous TDP-43. TDP-43 Q331K mice develop age- and mutant-dependent motor deficits from degeneration and death of motor neurons. Cre-recombinase-mediated excision of the TDP-43 Q331K gene from motor neurons is shown to delay onset of motor symptoms and appearance of TDP-43-mediated aberrant nuclear morphology, and abrogate subsequent death of motor neurons. However, reduction of mutant TDP-43 selectively in motor neurons did not prevent age-dependent degeneration of axons and neuromuscular junction loss, nor did it attenuate astrogliosis or microgliosis. Thus, disease mechanism is non-cell autonomous with mutant TDP-43 expressed in motor neurons determining disease onset but progression defined by mutant acting within other cell types.

Impaired ventilatory acclimatization to hypoxia in mice lacking the immediate early gene fos B.

PubMed

Malik, Mohammad T; Peng, Ying-Jie; Kline, David D; Adhikary, Gautam; Prabhakar, Nanduri R

2005-01-15

Earlier studies on cell culture models suggested that immediate early genes (IEGs) play an important role in cellular adaptations to hypoxia. Whether IEGs are also necessary for hypoxic adaptations in intact animals is not known. In the present study we examined the potential importance of fos B, an IEG in ventilatory acclimatization to hypoxia. Experiments were performed on wild type and mutant mice lacking the fos B gene. Ventilation was monitored by whole body plethysmography in awake animals. Baseline ventilation under normoxia, and ventilatory response to acute hypoxia and hypercapnia were comparable between wild type and mutant mice. Hypobaric hypoxia (0.4 atm; 3 days) resulted in a significant elevation of baseline ventilation in wild type but not in mutant mice. Wild type mice exposed to hypobaric hypoxia manifested an enhanced hypoxic ventilatory response compared to pre-hypobaric hypoxia. In contrast, hypobaric hypoxia had no effect on the hypoxic ventilatory response in mutant mice. Hypercapnic ventilatory responses, however, were unaffected by hypobaric hypoxia in both groups of mice. These results suggest that the fos B, an immediate early gene, plays an important role in ventilatory acclimatization to hypoxia in mice.

Autism-like socio-communicative deficits and stereotypies in mice lacking heparan sulfate.

PubMed

Irie, Fumitoshi; Badie-Mahdavi, Hedieh; Yamaguchi, Yu

2012-03-27

Heparan sulfate regulates diverse cell-surface signaling events, and its roles in the development of the nervous system recently have been increasingly uncovered by studies using genetic models carrying mutations of genes encoding enzymes for its synthesis. On the other hand, the role of heparan sulfate in the physiological function of the adult brain has been poorly characterized, despite several pieces of evidence suggesting its role in the regulation of synaptic function. To address this issue, we eliminated heparan sulfate from postnatal neurons by conditionally inactivating Ext1, the gene encoding an enzyme essential for heparan sulfate synthesis. Resultant conditional mutant mice show no detectable morphological defects in the cytoarchitecture of the brain. Remarkably, these mutant mice recapitulate almost the full range of autistic symptoms, including impairments in social interaction, expression of stereotyped, repetitive behavior, and impairments in ultrasonic vocalization, as well as some associated features. Mapping of neuronal activation by c-Fos immunohistochemistry demonstrates that neuronal activation in response to social stimulation is attenuated in the amygdala in these mice. Electrophysiology in amygdala pyramidal neurons shows an attenuation of excitatory synaptic transmission, presumably because of the reduction in the level of synaptically localized AMPA-type glutamate receptors. Our results demonstrate that heparan sulfate is critical for normal functioning of glutamatergic synapses and that its deficiency mediates socio-communicative deficits and stereotypies characteristic for autism.

Autism-like socio-communicative deficits and stereotypies in mice lacking heparan sulfate

PubMed Central

Irie, Fumitoshi; Badie-Mahdavi, Hedieh; Yamaguchi, Yu

2012-01-01

Heparan sulfate regulates diverse cell-surface signaling events, and its roles in the development of the nervous system recently have been increasingly uncovered by studies using genetic models carrying mutations of genes encoding enzymes for its synthesis. On the other hand, the role of heparan sulfate in the physiological function of the adult brain has been poorly characterized, despite several pieces of evidence suggesting its role in the regulation of synaptic function. To address this issue, we eliminated heparan sulfate from postnatal neurons by conditionally inactivating Ext1, the gene encoding an enzyme essential for heparan sulfate synthesis. Resultant conditional mutant mice show no detectable morphological defects in the cytoarchitecture of the brain. Remarkably, these mutant mice recapitulate almost the full range of autistic symptoms, including impairments in social interaction, expression of stereotyped, repetitive behavior, and impairments in ultrasonic vocalization, as well as some associated features. Mapping of neuronal activation by c-Fos immunohistochemistry demonstrates that neuronal activation in response to social stimulation is attenuated in the amygdala in these mice. Electrophysiology in amygdala pyramidal neurons shows an attenuation of excitatory synaptic transmission, presumably because of the reduction in the level of synaptically localized AMPA-type glutamate receptors. Our results demonstrate that heparan sulfate is critical for normal functioning of glutamatergic synapses and that its deficiency mediates socio-communicative deficits and stereotypies characteristic for autism. PMID:22411800

Overexpressing wild-type γ2 subunits rescued the seizure phenotype in Gabrg2+/Q390X Dravet syndrome mice.

PubMed

Huang, Xuan; Zhou, Chengwen; Tian, Mengnan; Kang, Jing-Qiong; Shen, Wangzhen; Verdier, Kelienne; Pimenta, Aurea; MacDonald, Robert L

2017-08-01

The mutant γ-aminobutyric acid type A (GABA A ) receptor γ2(Q390X) subunit (Q351X in the mature peptide) has been associated with the epileptic encephalopathy, Dravet syndrome, and the epilepsy syndrome genetic epilepsy with febrile seizures plus (GEFS+). The mutation generates a premature stop codon that results in translation of a stable truncated and misfolded γ2 subunit that accumulates in neurons, forms intracellular aggregates, disrupts incorporation of γ2 subunits into GABA A receptors, and affects trafficking of partnering α and β subunits. Heterozygous Gabrg2 +/Q390X knock-in (KI) mice had reduced cortical inhibition, spike wave discharges on electroencephalography (EEG), a lower seizure threshold to the convulsant drug pentylenetetrazol (PTZ), and spontaneous generalized tonic-clonic seizures. In this proof-of-principal study, we attempted to rescue these deficits in KI mice using a γ2 subunit gene (GABRG2) replacement therapy. We introduced the GABRG2 allele by crossing Gabrg2 +/Q390X KI mice with bacterial artificial chromosome (BAC) transgenic mice overexpressing HA (hemagglutinin)-tagged human γ2 HA subunits, and compared GABA A receptor subunit expression by Western blot and immunohistochemical staining, seizure threshold by monitoring mouse behavior after PTZ-injection, and thalamocortical inhibition and network oscillation by slice recording. Compared to KI mice, adult mice carrying both mutant allele and transgene had increased wild-type γ2 and partnering α1 and β2/3 subunits, increased miniature inhibitory postsynaptic current (mIPSC) amplitudes recorded from layer VI cortical neurons, reduced thalamocortical network oscillations, and higher PTZ seizure threshold. Based on these results we suggest that seizures in a genetic epilepsy syndrome caused by epilepsy mutant γ2(Q390X) subunits with dominant negative effects could be rescued potentially by overexpression of wild-type γ2 subunits. Wiley Periodicals, Inc. © 2017 International

Bypass of lethality with mosaic mice generated by Cre-loxP-mediated recombination.

PubMed

Betz, U A; Vosshenrich, C A; Rajewsky, K; Müller, W

1996-10-01

The analysis of gene function based on the generation of mutant mice by homologous recombination in embryonic stem cells is limited if gene disruption results in embryonic lethality. Mosaic mice, which contain a certain proportion of mutant cells in all organs, allow lethality to be circumvented and the potential of mutant cells to contribute to different cell lineages to be analyzed. To generate mosaic animals, we used the bacteriophage P1-derived Cre-loxP recombination system, which allows gene alteration by Cre-mediated deletion of loxP-flanked gene segments. We generated nestin-cre transgenic mouse lines, which expressed the Cre recombinase under the control of the rat nestin promoter and its second intron enhancer. In crosses to animals carrying a loxP-flanked target gene, partial deletion of the loxP-flanked allele occurred before day 10.5 post coitum and was detectable in all adult organs examined, including germ-line cells. Using this approach, we generated mosaic mice containing cells deficient in the gamma-chain of the interleukin-2 receptor (IL-2R gamma); in these animals, the IL-2R gamma-deficient cells were underrepresented in the thymus and spleen. Because mice deficient in DNA polymerase beta die perinatally, we studied the effects of DNA polymerase beta deficiency in mosaic animals. We found that some of the mosaic polymerase beta-deficient animals were viable, but were often reduced in size and weight. The fraction of DNA polymerase beta-deficient cells in mosaic embryos decreased during embryonic development, presumably because wild-type cells had a competitive advantage. The nestin-cre transgenic mice can be used to generate mosaic animals in which target genes are mutated by Cre-mediated recombination of loxP-flanked target genes. By using mosaic animals, embryonic lethality can be bypassed and cell lineages for whose development a given target gene is critical can be identified. In the case of DNA polymerase beta, deficient cells are already

Copper/zinc superoxide dismutase insufficiency impairs progesterone secretion and fertility in female mice.

PubMed

Noda, Yoshihiro; Ota, Kuniaki; Shirasawa, Takuji; Shimizu, Takahiko

2012-01-01

Copper/zinc superoxide dismutase (CuZn-SOD, SOD1) is one of the major antioxidant enzymes, and is localized in the cytoplasm to scavenge superoxide. To investigate the physiological role of SOD1 in the ovaries, we analyzed the fertility of Sod1-deficient female mice. To evaluate their hormonal metabolism, we measured pituitary and ovarian hormone levels in the plasma of the mutant mice. Plasma follicle-stimulating hormone, luteinizing hormone, and estradiol were not altered in the mutant compared to the wild-type females, while the plasma progesterone level was significantly reduced in the mutant females. Furthermore, the mutant mice showed decreased progesterone secretion under the condition of superovulation. In a histochemical analysis, we observed a remarkable reduction in the corpus luteum area in the mutant ovaries without atrophic changes. The mutant mice also displayed enhanced superoxide generation in the region surrounding the corpora lutea, which was associated with increased apoptotic cells and suppressed vasculature. These results suggested that SOD1 deficiency dysregulated luteal formation because of increased superoxide generation in the ovary. In vitro fertilization experiments showed no abnormal fertilization of Sod1-deficient oocytes. In addition, when Sod1-deficient embryos were transferred into the oviducts of wild-type females, mutant embryos developed at a normal rate, indicating that SOD1 deficiency in embryos did not cause miscarriage in the uterus of wild-type females. These results indicated that increased intracellular ROS impaired luteal formation and progesterone production in the mutant females, thus suggesting that SOD1 plays a crucial role in both the luteal function and the maintenance of fertility in female mice.

A Mutant Receptor Tyrosine Phosphatase, CD148, Causes Defects in Vascular Development

PubMed Central

Takahashi, Takamune; Takahashi, Keiko; St. John, Patricia L.; Fleming, Paul A.; Tomemori, Takuya; Watanabe, Toshio; Abrahamson, Dale R.; Drake, Christopher J.; Shirasawa, Takuji; Daniel, Thomas O.

2003-01-01

Vascularization defects in genetic recombinant mice have defined critical roles for a number of specific receptor tyrosine kinases. Here we evaluated whether an endothelium-expressed receptor tyrosine phosphatase, CD148 (DEP-1/PTPη), participates in developmental vascularization. A mutant allele, CD148ΔCyGFP, was constructed to eliminate CD148 phosphatase activity by in-frame replacement of cytoplasmic sequences with enhanced green fluorescent protein sequences. Homozygous mutant mice died at midgestation, before embryonic day 11.5 (E11.5), with vascularization failure marked by growth retardation and disorganized vascular structures. Structural abnormalities were observed as early as E8.25 in the yolk sac, prior to the appearance of intraembryonic defects. Homozygous mutant mice displayed enlarged vessels comprised of endothelial cells expressing markers of early differentiation, including VEGFR2 (Flk1), Tal1/SCL, CD31, ephrin-B2, and Tie2, with notable lack of endoglin expression. Increased endothelial cell numbers and mitotic activity indices were demonstrated. At E9.5, homozygous mutant embryos showed homogeneously enlarged primitive vessels defective in vascular remodeling and branching, with impaired pericyte investment adjacent to endothelial structures, in similarity to endoglin-deficient embryos. Developing cardiac tissues showed expanded endocardial projections accompanied by defective endocardial cushion formation. These findings implicate a member of the receptor tyrosine phosphatase family, CD148, in developmental vascular organization and provide evidence that it regulates endothelial proliferation and endothelium-pericyte interactions. PMID:12588999

Adult Behavior in Male Mice Exposed to E-Cigarette Nicotine Vapors during Late Prenatal and Early Postnatal Life

PubMed Central

Smith, Dani; Aherrera, Angela; Lopez, Armando; Neptune, Enid; Winickoff, Jonathan P.; Klein, Jonathan D.; Chen, Gang; Lazarus, Philip; Collaco, Joseph M.; McGrath-Morrow, Sharon A.

2015-01-01

Nicotine exposure has been associated with an increased likelihood of developing attention deficit hyperactivity disorder (ADHD) in offspring of mothers who smoked during pregnancy. The goal of this study was to determine if exposure to E-cigarette nicotine vapors during late prenatal and early postnatal life altered behavior in adult mice. Methods Timed-pregnant C57BL/6J mice were exposed to 2.4% nicotine in propylene glycol (PG) or 0% nicotine /PG once a day from gestational day 15 until delivery. After delivery, offspring and mothers were exposed to E-cigarette vapors for an additional 14 days from postnatal day 2 through 16. Following their last exposure serum cotinine levels were measured in female juvenile mice. Male mice underwent behavioral testing at 14 weeks of age to assess sensorimotor, affective, and cognitive functional domains. Results Adult male mice exposed to 2.4% nicotine/PG E-cigarette vapors had significantly more head dips in the zero maze test and higher levels of rearing activity in the open field test compared to 0% nicotine/PG exposed mice and untreated controls. In the water maze test after reversal training, the 2.4% nicotine/PG mice spent more than 25% of time in the new location whereas the other groups did not. Conclusion Adult male mice exhibited increased levels of activity in the zero maze and open field tests when exposed to E-cigarette vapor containing nicotine during late prenatal and early postnatal life. These findings indicate that nicotine exposure from E-cigarettes may cause persistent behavioral changes when exposure occurs during a period of rapid brain growth. PMID:26372012

Molecular mechanisms mediating a deficit in recall of fear extinction in adult mice exposed to cocaine in utero.

PubMed

Kabir, Zeeba D; Katzman, Aaron C; Kosofsky, Barry E

2013-01-01

Prenatal cocaine exposure has been shown to alter cognitive processes of exposed individuals, presumed to be a result of long-lasting molecular alterations in the brain. In adult prenatal cocaine exposed (PCOC) mice we have identified a deficit in recall of fear extinction, a behavior that is dependent on the medial prefrontal cortex (mPFC) and the hippocampus. While we observed no change in the constitutive expression of brain derived neurotrophic factor (BDNF) protein and mRNA in the mPFC and hippocampus of adult PCOC mice, we observed blunted BDNF signaling in the mPFC of adult PCOC mice after fear extinction compared to the control animals. Specifically, during the consolidation phase of the extinction memory, we observed a decrease in BDNF protein and it's phospho-TrkB receptor expression. Interestingly, at this same time point there was a significant increase in total Bdnf mRNA levels in the mPFC of PCOC mice as compared with controls. In the Bdnf gene, we identified decreased constitutive binding of the transcription factors, MeCP2 and P-CREB at the promoters of Bdnf exons I and IV in the mPFC of PCOC mice, that unlike control mice remained unchanged when measured during the behavior. Finally, bilateral infusion of recombinant BDNF protein into the infralimbic subdivision of the mPFC during the consolidation phase of the extinction memory rescued the behavioral deficit in PCOC mice. In conclusion, these findings extend our knowledge of the neurobiologic impact of prenatal cocaine exposure on the mPFC of mice, which may lead to improved clinical recognition and treatment of exposed individuals.

The individuality of mice.

PubMed

Lathe, R

2004-12-01

Mutant mice simulating human CNS disorders are used as models for therapeutic drug development. Drug evaluation requires a coherent correlation between behavioral phenotype and drug status. Variations in behavioral responses could mask such correlations, a problem highlighted by the three-site studies of Crabbe et al. (1999) and Wahlsten et al. (2003a). Factors contributing to variation are considered, focusing on differences between individual animals. Genetic differences due to minisatellite variation suggest that each mouse is genetically distinct. Effects during gestation, including maternal stress, influence later life behavior; while endocrine exchanges between fetus and parent, and between male and female fetuses dependent on intrauterine position, also contribute. Pre and perinatal nutrition and maternal attention also play a role. In adults, endocrine cyclicity in females is a recognized source of behavioral diversity. Notably, there is increasing recognition that groups of wild and laboratory mice have complex social structures, illustrated through consideration of Crowcroft (1966). Dominance status can markedly modify behavior in test paradigms addressing anxiety, locomotion and aggressiveness, to an extent comparable to mutation or drug status. Understanding how such effects amplify the behavioral spectrum displayed by otherwise identical animals will improve testing.

Reduced wheel running and blunted effects of voluntary exercise in LPA1-null mice: the importance of assessing the amount of running in transgenic mice studies.

PubMed

Castilla-Ortega, Estela; Rosell-Valle, Cristina; Blanco, Eduardo; Pedraza, Carmen; Chun, Jerold; Rodríguez de Fonseca, Fernando; Estivill-Torrús, Guillermo; Santín, Luis J

2013-11-01

This work was aimed to assess whether voluntary exercise rescued behavioral and hippocampal alterations in mice lacking the lysophosphatidic acid LPA1 receptor (LPA1-null mice), studying the potential relationship between the amount of exercise performed and its effects. Normal and LPA1-null mice underwent 23 days of free wheel running and were tested for open-field behavior and adult hippocampal neurogenesis (cell proliferation, immature neurons, cell survival). Running decreased anxiety-like behavior in both genotypes but increased exploration only in the normal mice. While running affected all neurogenesis-related measures in normal mice (especially in the suprapyramidal blade of the dentate gyrus), only a moderate increase in cell survival was found in the mutants. Importantly, the LPA1-nulls showed notably reduced running. Analysis suggested that defective running in the LPA1-null mice could contribute to explain the scarce benefit of the voluntary exercise treatment. On the other hand, a literature review revealed that voluntary exercise is frequently used to modulate behavior and the hippocampus in transgenic mice, but half of the studies did not assess the quantity of running, overlooking any potential running impairments. This study adds evidence to the relevance of the quantity of exercise performed, emphasizing the importance of its assessment in transgenic mice research. Copyright © 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Effect of CCS on the Accumulation of FALS SOD1 Mutant-containing Aggregates and on Mitochondrial Translocation of SOD1 Mutants: Implication of a Free Radical Hypothesis

PubMed Central

Kim, Ha Kun; Chung, Youn Wook; Chock, P. Boon; Yim, Moon B.

2011-01-01

Missense mutations of SOD1 are linked to familial amyotrophic lateral sclerosis (FALS) through a yet-to-be identified toxic-gain-of-function. One of the proposed mechanisms involves enhanced aggregate formation. However, a recent study showed that dual transgenic mice overexpressing both G93A and CCS copper chaperone (G93A/CCS) exhibit no SOD1-positive aggregates yet show accelerated FALS symptoms with enhanced mitochondrial pathology compared to G93A mice. Using a dicistronic mRNA to simultaneously generate hSOD1 mutants, G93A, A4V and G85R, and hCCS in AAV293 cells, we revealed: (i) CCS is degraded primarily via a macroautophagy pathway. It forms a stable heterodimer with inactive G85R, and via its novel copper chaperone-independent molecular chaperone activity facilitates G85R degradation via a macroautophagy-mediated pathway. For active G93A and A4V, CCS catalyzes their maturation to form active and soluble homodimers. (ii) CCS reduces, under non-oxidative conditions, yet facilitates in the presence of H2O2, mitochondrial translocation of inactive SOD1 mutants. These results, together with previous reports showing FALS SOD1 mutants enhanced free radical-generating activity, provide a mechanistic explanation for the observations with G93A/CCS dual transgenic mice and suggest that free radical generation by FALS SOD1, enhanced by CCS, may, in part, be responsible for the FALS SOD1 mutant-linked aggregation, mitochondrial translocation, and degradation. PMID:21354101

Effect of CCS on the accumulation of FALS SOD1 mutant-containing aggregates and on mitochondrial translocation of SOD1 mutants: implication of a free radical hypothesis.

PubMed

Kim, Ha Kun; Chung, Youn Wook; Chock, P Boon; Yim, Moon B

2011-05-15

Missense mutations of SOD1 are linked to familial amyotrophic lateral sclerosis (FALS) through a yet-to-be identified toxic-gain-of-function. One of the proposed mechanisms involves enhanced aggregate formation. However, a recent study showed that dual transgenic mice overexpressing both G93A and CCS copper chaperone (G93A/CCS) exhibit no SOD1-positive aggregates yet show accelerated FALS symptoms with enhanced mitochondrial pathology compared to G93A mice. Using a dicistronic mRNA to simultaneously generate hSOD1 mutants, G93A, A4V and G85R, and hCCS in AAV293 cells, we revealed: (i) CCS is degraded primarily via a macroautophagy pathway. It forms a stable heterodimer with inactive G85R, and via its novel copper chaperone-independent molecular chaperone activity facilitates G85R degradation via a macroautophagy-mediated pathway. For active G93A and A4V, CCS catalyzes their maturation to form active and soluble homodimers. (ii) CCS reduces, under non-oxidative conditions, yet facilitates in the presence of H(2)O(2), mitochondrial translocation of inactive SOD1 mutants. These results, together with previous reports showing FALS SOD1 mutants enhanced free radical-generating activity, provide a mechanistic explanation for the observations with G93A/CCS dual transgenic mice and suggest that free radical generation by FALS SOD1, enhanced by CCS, may, in part, be responsible for the FALS SOD1 mutant-linked aggregation, mitochondrial translocation, and degradation. Published by Elsevier Inc.

Exposure to neonatal cigarette smoke causes durable lung changes but does not potentiate cigarette smoke–induced chronic obstructive pulmonary disease in adult mice

PubMed Central

McGrath-Morrow, Sharon; Malhotra, Deepti; Lauer, Thomas; Collaco, J. Michael; Mitzner, Wayne; Neptune, Enid; Wise, Robert; Biswal, Shyam

2016-01-01

The impact of early childhood cigarette smoke (CS) exposure on CS-induced chronic obstructive pulmonary disease (COPD) is unknown. This study was performed to evaluate the individual and combined effects of neonatal and adult CS exposure on lung structure, function, and gene expression in adult mice. To model a childhood CS exposure, neonatal C57/B6 mice were exposed to 14 days of CS (Neo CS). At 10 weeks of age, Neo CS and control mice were exposed to 4 months of CS. Pulmonary function tests, bronchoalveolar lavage, and lung morphometry were measured and gene expression profiling was performed on lung tissue. Mean chord lengths and lung volumes were increased in neonatal and/or adult CS-exposed mice. Differences in immune, cornified envelope protein, muscle, and erythrocyte genes were found in CS-exposed lung. Neonatal CS exposure caused durable structural and functional changes in the adult lung but did not potentiate CS-induced COPD changes. Cornified envelope protein gene expression was decreased in all CS-exposed mice, whereas myosin and erythrocyte gene expression was increased in mice exposed to both neonatal and adult CS, suggesting an adaptive response. Additional studies may be warranted to determine the utility of these genes as biomarkers of respiratory outcomes. PMID:21649527

Prenatal ethanol weakens the efficacy of reinforcers for adult mice.

PubMed

Gentry, G D; Middaugh, L D

1988-02-01

Pregnant C57BL/6cr mice were fed a liquid diet containing 20% of the total calories from either ethanol (E) or sucrose (S) for gestation days 5-17. Adult male and female (six of each from both prenatal-treatment groups) offspring were tested under various schedules of food reinforcement. The first phase was a test of fixed-ratio (FR) acquisition in which the required number of responses per unit of reinforcement was increased from 1 to 20 to 100. Prenatal ethanol exposure interacted with other factors to produce an acquisition deficit. The second phase involved responding under extinction (Ext). Under standard Ext procedures there were no prenatal-ethanol effects; however, when a conditioned reinforcer was superimposed on an FR 5, the E males did not increase their rates as much as the S males. Finally, under a multiple FR 5 DRO 15-sec (differential-reinforcement-of-other-behavior) arrangement, prenatal-ethanol effects were found in each component. For the FR 5 component, prenatal ethanol eliminated the sex differences found in the S subjects. For the DRO 15-sec component, prenatal ethanol elevated response rates. The results indicate a general decreased efficacy of positive reinforcement in adult mice following prenatal ethanol exposure.

Effects of ethanol on immune response in the brain: region-specific changes in adolescent versus adult mice.

PubMed

Kane, Cynthia J M; Phelan, Kevin D; Douglas, James C; Wagoner, Gail; Johnson, Jennifer W; Xu, Jihong; Phelan, Patrick S; Drew, Paul D

2014-02-01

Alcohol use occurs across the life span beginning in adolescence and continuing through adulthood. Ethanol (EtOH)-induced pathology varies with age and includes changes in neurogenesis, neurodegeneration, and glial cell activation. EtOH-induced changes in glial activation and immune activity are believed to contribute to EtOH-induced neuropathology. Recent studies indicate an emerging role of glial-derived neuroimmune molecules in alcohol abuse and addiction. Adolescent and adult C57BL/6 mice were treated via gavage with 6 g/kg EtOH for 10 days, and tissue was harvested 1 day post treatment. We compared the effects of EtOH on chemokine and cytokine expression and astrocyte glial fibrillary acidic protein (GFAP) immunostaining and morphology in the hippocampus, cerebellum, and cerebral cortex. EtOH increased mRNA levels of the chemokine CCL2/MCP-1 in all 3 regions of adult mice relative to controls. The cytokine interleukin-6 (IL-6) was selectively increased only in the adult cerebellum. EtOH did not affect mRNA levels of the cytokine tumor necrosis factor-alpha (TNF-α) in any of these brain regions in adult animals. Interestingly, CCL2, IL-6, and TNF-α mRNA levels were not increased in the hippocampus, cerebellum, or cortex of adolescent mice. EtOH treatment of adult and adolescent mice resulted in increased GFAP immunostaining. Collectively, these data indicate an age- and region-specific susceptibility to EtOH regulation of neuroinflammatory and addiction-related molecules as well as astrocyte phenotype. These studies may have important implications concerning differential alcohol-induced neuropathology and alcohol addiction across the life span. Copyright © 2013 by the Research Society on Alcoholism.

Early postnatal motor experience shapes the motor properties of C57BL/6J adult mice.

PubMed

Serradj, Nadjet; Picquet, Florence; Jamon, Marc

2013-11-01

This study aimed to evaluate the long-term consequences of early motor training on the muscle phenotype and motor output of middle-aged C57BL/6J mice. Neonatal mice were subjected to a variety of motor training procedures, for 3 weeks during the period of acquisition of locomotion. These procedures are widely used for motor training in adults; they include enriched environment, forced treadmill, chronic centrifugation, and hindlimb suspension. At 9 months, the mice reared in the enriched environment showed a slower type of fibre in slow muscles and a faster type in fast muscles, improved performance in motor tests, and a modified gait and body posture while walking. The proportion of fibres in the postural muscles of centrifuged mice did not change, but these mice showed improved resistance to fatigue. The suspended mice showed increased persistence of immature hybrid fibres in the tibialis, with a slower shift in the load-bearing soleus, without any behavioural changes. The forced treadmill was very stressful for the mice, but had limited effects on motor output, although a slower profile was observed in the tibialis. These results support the hypothesis that motor experience during a critical period of motor development shapes muscle phenotype and motor output. The different impacts of the various training procedures suggest that motor performance in adults can be optimized by appropriate training during a defined period of motor development. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Low levels of endogenous or X-ray-induced DNA double-strand breaks activate apoptosis in adult neural stem cells.

PubMed

Barazzuol, Lara; Rickett, Nicole; Ju, Limei; Jeggo, Penny A

2015-10-01

The embryonic neural stem cell compartment is characterised by rapid proliferation from embryonic day (E)11 to E16.5, high endogenous DNA double-strand break (DSB) formation and sensitive activation of apoptosis. Here, we ask whether DSBs arise in the adult neural stem cell compartments, the sub-ventricular zone (SVZ) of the lateral ventricles and the sub-granular zone (SGZ) of the hippocampal dentate gyrus, and whether they activate apoptosis. We used mice with a hypomorphic mutation in DNA ligase IV (Lig4(Y288C)), ataxia telangiectasia mutated (Atm(-/-)) and double mutant Atm(-/-)/Lig4(Y288C) mice. We demonstrate that, although DSBs do not arise at a high frequency in adult neural stem cells, the low numbers of DSBs that persist endogenously in Lig4(Y288C) mice or that are induced by low radiation doses can activate apoptosis. A temporal analysis shows that DSB levels in Lig4(Y288C) mice diminish gradually from the embryo to a steady state level in adult mice. The neonatal SVZ compartment of Lig4(Y288C) mice harbours diminished DSBs compared to its differentiated counterpart, suggesting a process selecting against unfit stem cells. Finally, we reveal high endogenous apoptosis in the developing SVZ of wild-type newborn mice. © 2015. Published by The Company of Biologists Ltd.

Mice with GFAP-targeted loss of neurofibromin demonstrate increased axonal MET expression with aging.

PubMed

Su, Weiping; Xing, Rubing; Guha, Abhijit; Gutmann, David H; Sherman, Larry S

2007-05-01

Neurofibromatosis 1 (NF1) is a common genetic disease that predisposes patients to peripheral nerve tumors and central nervous system (CNS) abnormalities including low-grade astrocytomas and cognitive disabilities. Using mice with glial fibrillary acidic protein (GFAP)-targeted Nf1 loss (Nf1(GFAP)CKO mice), we found that Nf1(-/-) astrocytes proliferate faster and are more invasive than wild-type astrocytes. In light of our previous finding that aberrant expression of the MET receptor tyrosine kinase contributes to the invasiveness of human NF1-associated malignant peripheral nerve sheath tumors, we sought to determine whether MET expression is aberrant in the brains of Nf1 mutant mice. We found that Nf1(-/-) astrocytes express slightly more MET than wild-type cells in vitro, but do not express elevated MET in situ. However, fiber tracts containing myelinated axons in the hippocampus, midbrain, cerebral cortex, and cerebellum express higher than normal levels of MET in older (> or =6 months) Nf1(GFAP)CKO mice. Both Nf1(GFAP)CKO and wild-type astrocytes induced MET expression in neurites of wild-type hippocampal neurons in vitro, suggesting that astrocyte-derived signals may induce MET in Nf1 mutant mice. Because the Nf1 gene product functions as a RAS GTPase, we examined MET expression in the brains of mice with GFAP-targeted constitutively active forms of RAS. MET was elevated in axonal fiber tracts in mice with active K-RAS but not H-RAS. Collectively, these data suggest that loss of Nf1 in either astrocytes or GFAP(+) neural progenitor cells results in increased axonal MET expression, which may contribute to the CNS abnormalities in children and adults with NF1. (c) 2007 Wiley-Liss, Inc.

Mecp2 truncation in male mice promotes affiliative social behavior

PubMed Central

Pearson, B.L.; Defensor, E.B.; Pobbe, R.L.H.; Yamamoto, L.H.L.; Bolivar, V.J.; Blanchard, D.C.; Blanchard, R.J.

2018-01-01

Mouse models of Rett syndrome, with targeted mutations in the Mecp2 gene, show a high degree of phenotypic consistency with the clinical syndrome. In addition to severe and age-specific regression in motor and cognitive abilities, a variety of studies have demonstrated that Mecp2 mutant mice display impaired social behavior. Conversely, other studies indicate complex enhancements of social behavior in Mecp2 mutant mice. Since social behavior is a complicated accumulation of constructs, we performed a series of classic and refined social behavior tasks and revealed a relatively consistent pattern of enhanced pro-social behavior in hypomorphic Mecp2308/Y mutant mice. Analyses of repetitive motor acts, and cognitive stereotypy did not reveal any profound differences due to genotype. Taken together, these results suggest that the mutations associated with Rett syndrome are not necessarily associated with autism-relevant social impairment in mice. However, this gene may be a valuable candidate for revealing basic mechanisms of affiliative behavior. PMID:21909962

Herpes Simplex Virus 1 Mutant with Point Mutations in UL39 Is Impaired for Acute Viral Replication in Mice, Establishment of Latency, and Explant-Induced Reactivation.

PubMed

Mostafa, Heba H; Thompson, Thornton W; Konen, Adam J; Haenchen, Steve D; Hilliard, Joshua G; Macdonald, Stuart J; Morrison, Lynda A; Davido, David J

2018-04-01

In the process of generating herpes simplex virus 1 (HSV-1) mutations in the viral regulatory gene encoding infected cell protein 0 (ICP0), we isolated a viral mutant, termed KOS-NA, that was severely impaired for acute replication in the eyes and trigeminal ganglia (TG) of mice, defective in establishing a latent infection, and reactivated poorly from explanted TG. To identify the secondary mutation(s) responsible for the impaired phenotypes of this mutant, we sequenced the KOS-NA genome and noted that it contained two nonsynonymous mutations in UL39 , which encodes the large subunit of ribonucleotide reductase, ICP6. These mutations resulted in lysine-to-proline (residue 393) and arginine-to-histidine (residue 950) substitutions in ICP6. To determine whether alteration of these amino acids was responsible for the KOS-NA phenotypes in vivo , we recombined the wild-type UL39 gene into the KOS-NA genome and rescued its acute replication phenotypes in mice. To further establish the role of UL39 in KOS-NA's decreased pathogenicity, the UL39 mutations were recombined into HSV-1 (generating UL39 mut ), and this mutant virus showed reduced ocular and TG replication in mice comparable to that of KOS-NA. Interestingly, ICP6 protein levels were reduced in KOS-NA-infected cells relative to the wild-type protein. Moreover, we observed that KOS-NA does not counteract caspase 8-induced apoptosis, unlike wild-type strain KOS. Based on alignment studies with other HSV-1 ICP6 homologs, our data suggest that amino acid 950 of ICP6 likely plays an important role in ICP6 accumulation and inhibition of apoptosis, consequently impairing HSV-1 pathogenesis in a mouse model of HSV-1 infection. IMPORTANCE HSV-1 is a major human pathogen that infects ∼80% of the human population and can be life threatening to infected neonates or immunocompromised individuals. Effective therapies for treatment of recurrent HSV-1 infections are limited, which emphasizes a critical need to understand in

Subthreshold membrane potential oscillations in inferior olive neurons are dynamically regulated by P/Q- and T-type calcium channels: a study in mutant mice.

PubMed

Choi, Soonwook; Yu, Eunah; Kim, Daesoo; Urbano, Francisco J; Makarenko, Vladimir; Shin, Hee-Sup; Llinás, Rodolfo R

2010-08-15

The role of P/Q- and T-type calcium channels in the rhythmic oscillatory behaviour of inferior olive (IO) neurons was investigated in mutant mice. Mice lacking either the CaV2.1 gene of the pore-forming alpha1A subunit for P/Q-type calcium channel, or the CaV3.1 gene of the pore-forming alpha1G subunit for T-type calcium channel were used. In vitro intracellular recording from IO neurons reveals that the amplitude and frequency of sinusoidal subthreshold oscillations (SSTOs) were reduced in the CaV2.1-/- mice. In the CaV3.1-/- mice, IO neurons also showed altered patterns of SSTOs and the probability of SSTO generation was significantly lower (15%, 5 of 34 neurons) than that of wild-type (78%, 31 of 40 neurons) or CaV2.1-/- mice (73%, 22 of 30 neurons). In addition, the low-threshold calcium spike and the sustained endogenous oscillation following rebound potentials were absent in IO neurons from CaV3.1-/- mice. Moreover, the phase-reset dynamics of oscillatory properties of single neurons and neuronal clusters in IO were remarkably altered in both CaV2.1-/- and CaV3.1-/- mice. These results suggest that both alpha1A P/Q- and alpha1G T-type calcium channels are required for the dynamic control of neuronal oscillations in the IO. These findings were supported by results from a mathematical IO neuronal model that incorporated T and P/Q channel kinetics.

Progressive Motor Deficit is Mediated by the Denervation of Neuromuscular Junctions and Axonal Degeneration in Transgenic Mice Expressing Mutant (P301S) Tau Protein.

PubMed

Yin, Zhuoran; Valkenburg, Femke; Hornix, Betty E; Mantingh-Otter, Ietje; Zhou, Xingdong; Mari, Muriel; Reggiori, Fulvio; Van Dam, Debby; Eggen, Bart J L; De Deyn, Peter P; Boddeke, Erik

2017-01-01

Tauopathies include a variety of neurodegenerative diseases associated with the pathological aggregation of hyperphosphorylated tau, resulting in progressive cognitive decline and motor impairment. The underlying mechanism for motor deficits related to tauopathy is not yet fully understood. Here, we use a novel transgenic tau mouse line, Tau 58/4, with enhanced neuron-specific expression of P301S mutant tau to investigate the motor abnormalities in association with the peripheral nervous system. Using stationary beam, gait, and rotarod tests, motor deficits were found in Tau 58/4 mice already 3 months after birth, which deteriorated during aging. Hyperphosphorylated tau was detected in the cell bodies and axons of motor neurons. At the age of 9 and 12 months, significant denervation of the neuromuscular junction in the extensor digitorum longus muscle was observed in Tau 58/4 mice, compared to wild-type mice. Muscle hypotrophy was observed in Tau 58/4 mice at 9 and 12 months. Using electron microscopy, we observed ultrastructural changes in the sciatic nerve of 12-month-old Tau 58/4 mice indicative of the loss of large axonal fibers and hypomyelination (assessed by g-ratio). We conclude that the accumulated hyperphosphorylated tau in the axon terminals may induce dying-back axonal degeneration, myelin abnormalities, neuromuscular junction denervation, and muscular atrophy, which may be the mechanisms responsible for the deterioration of the motor function in Tau 58/4 mice. Tau 58/4 mice represent an interesting neuromuscular degeneration model, and the pathological mechanisms might be responsible for motor signs observed in some human tauopathies.

Overweight and metabolic and hormonal parameter disruption are induced in adult male mice by manipulations during lactation period.

PubMed

Loizzo, Alberto; Loizzo, Stefano; Galietta, Gabriella; Caiola, Stefania; Spampinato, Santi; Campana, Gabriele; Seghieri, Giuseppe; Ghirlanda, Giovanni; Franconi, Flavia

2006-01-01

Neonatal manipulations (10 min of maternal separation plus s.c. sham injection, daily for the first 21 d of life) determine overweight in male adult mice. In this work, we investigated the mechanisms underlying mild obesity and the alteration of caloric balance. Neonatally manipulated mice become overweight after onset of maturity, showing increased fat tissue and hypertrophic epididymal adipocytes. Increase in body weight occurs in the presence of a small increase in daily food intake (significant only in the adult period) and the absence of a decrease in spontaneous locomotor activity, while the calculated caloric efficiency is higher in manipulated mice, especially in adulthood. Fasting adult animals show hyperglycemia, hyperinsulinemia, hypertriglyceridemia, hypercholesterolemia, and hyperleptinemia. Soon after weaning and in the adulthood, plasma corticosterone and adrenocorticotropin (ACTH) are also significantly increased. Thus, neonatal manipulations in nongenetically susceptible male mice program mild obesity, with metabolic and hormonal alterations that are similar to those found in experimental models of diabetes mellitus, suggesting that this metabolic derangement may have at least part of its roots early on in life and, more interestingly, that psychological and nociceptive stimuli induce these features.

PDGFRA-mutant syndrome.

PubMed

Ricci, Riccardo; Martini, Maurizio; Cenci, Tonia; Carbone, Arnaldo; Lanza, Paola; Biondi, Alberto; Rindi, Guido; Cassano, Alessandra; Larghi, Alberto; Persiani, Roberto; Larocca, Luigi M

2015-07-01

Germline PDGFRA mutations cause multiple heterogeneous gastrointestinal mesenchymal tumors. In its familial form this disease, which was formerly termed intestinal neurofibromatosis/neurofibromatosis 3b (INF/NF3b), has been included among familial gastrointestinal stromal tumors (GISTs) because of its genotype, described when GIST was the only known PDGFRA-mutant gastrointestinal tumor. Shortly afterwards, however, inflammatory fibroid polyps also revealed PDGFRA mutations. Subsequently, gastrointestinal CD34+ 'fibrous tumors' of uncertain classification were described in a germline PDGFRA-mutant context. Our aim was to characterize the syndrome produced by germline PDGFRA mutations and establish diagnostic criteria and management strategies for this hitherto puzzling disease. We studied a kindred displaying multiple gastrointestinal mesenchymal tumors, comparing it with published families/individuals with possible analogous conditions. We identified a novel inherited PDGFRA mutation (P653L), constituting the third reported example of familial PDGFRA mutation. In adult mutants we detected inflammatory fibroid polyps, gastric GISTs and gastrointestinal fibrous tumors of uncertain nosology. We demonstrate that the syndrome formerly defined as INF/NF3b (exemplified by the family reported herein) is simplistically considered a form of familial GIST, because inflammatory fibroid polyps often prevail. Fibrous tumors appear variants of inflammatory fibroid polyps. 'INF/NF3b' and 'familial GIST' are misleading terms which we propose changing to 'PDGFRA-mutant syndrome'. In this condition, unlike KIT-dependent familial GIST syndromes, if present, GISTs are stomach-restricted and diffuse Cajal cell hyperplasia is not observed. This restriction of GISTs to the stomach in PDGFRA-mutant syndrome: (i) focuses oncological concern on gastric masses, as inflammatory fibroid polyps are benign; (ii) supports a selective role of gastric environment for PDGFRA mutations to elicit GISTs

Mutant Huntingtin Causes a Selective Decrease in the Expression of Synaptic Vesicle Protein 2C.

PubMed

Peng, Chaohua; Zhu, Gaochun; Liu, Xiangqian; Li, He

2018-04-30

Huntington's disease (HD) is a neurodegenerative disease caused by a polyglutamine expansion in the huntingtin (Htt) protein. Mutant Htt causes synaptic transmission dysfunctions by interfering in the expression of synaptic proteins, leading to early HD symptoms. Synaptic vesicle proteins 2 (SV2s), a family of synaptic vesicle proteins including 3 members, SV2A, SV2B, and SV2C, plays important roles in synaptic physiology. Here, we investigated whether the expression of SV2s is affected by mutant Htt in the brains of HD transgenic (TG) mice and Neuro2a mouse neuroblastoma cells (N2a cells) expressing mutant Htt. Western blot analysis showed that the protein levels of SV2A and SV2B were not significantly changed in the brains of HD TG mice expressing mutant Htt with 82 glutamine repeats. However, in the TG mouse brain there was a dramatic decrease in the protein level of SV2C, which has a restricted distribution pattern in regions particularly vulnerable in HD. Immunostaining revealed that the immunoreactivity of SV2C was progressively weakened in the basal ganglia and hippocampus of TG mice. RT-PCR demonstrated that the mRNA level of SV2C progressively declined in the TG mouse brain without detectable changes in the mRNA levels of SV2A and SV2B, indicating that mutant Htt selectively inhibits the transcriptional expression of SV2C. Furthermore, we found that only SV2C expression was progressively inhibited in N2a cells expressing a mutant Htt containing 120 glutamine repeats. These findings suggest that the synaptic dysfunction in HD results from the mutant Htt-mediated inhibition of SV2C transcriptional expression. These data also imply that the restricted distribution and decreased expression of SV2C contribute to the brain region-selective pathology of HD.

Impaired locomotor activity and exploratory behavior in mice lacking histamine H1 receptors

PubMed Central

Inoue, Isao; Yanai, Kazuhiko; Kitamura, Daisuke; Taniuchi, Ichiro; Kobayashi, Takashi; Niimura, Kaku; Watanabe, Takehiko; Watanabe, Takeshi

1996-01-01

From pharmacological studies using histamine antagonists and agonists, it has been demonstrated that histamine modulates many physiological functions of the hypothalamus, such as arousal state, locomotor activity, feeding, and drinking. Three kinds of receptors (H1, H2, and H3) mediate these actions. To define the contribution of the histamine H1 receptors (H1R) to behavior, mutant mice lacking the H1R were generated by homologous recombination. In brains of homozygous mutant mice, no specific binding of [3H]pyrilamine was seen. [3H]Doxepin has two saturable binding sites with higher and lower affinities in brains of wild-type mice, but H1R-deficient mice showed only the weak labeling of [3H]doxepin that corresponds to lower-affinity binding sites. Mutant mice develop normally, but absence of H1R significantly increased the ratio of ambulation during the light period to the total ambulation for 24 hr in an accustomed environment. In addition, mutant mice significantly reduced exploratory behavior of ambulation and rearings in a new environment. These results indicate that through H1R, histamine is involved in circadian rhythm of locomotor activity and exploratory behavior as a neurotransmitter. PMID:8917588

Crimean-Congo hemorrhagic fever virus infection is lethal for adult type I interferon receptor-knockout mice.

PubMed

Bereczky, Sándor; Lindegren, Gunnel; Karlberg, Helen; Akerström, Sara; Klingström, Jonas; Mirazimi, Ali

2010-06-01

Crimean-Congo hemorrhagic fever virus (CCHFV) poses a great threat to public health due to its high mortality, transmission and geographical distribution. To date, there is no vaccine or specific treatment available and the knowledge regarding its pathogenesis is highly limited. Using a small-animal model system, this study showed that adult mice missing the type I interferon (IFN) receptor (IFNAR(-/-)) were susceptible to CCHFV and developed an acute disease with fatal outcome. In contrast, infection of wild-type mice (129 Sv/Ew) was asymptomatic. Viral RNA was found in all analysed organs of the infected mice, but the amount of CCHFV RNA was significantly higher in the IFNAR(-/-) mice than in the wild-type mice. Furthermore, the liver of IFNAR(-/-) mice was enlarged significantly, showing that IFN is important for limiting virus spread and protecting against liver damage in mice.

Repeatability and consistency of individual behaviour in juvenile and adult Eurasian harvest mice

NASA Astrophysics Data System (ADS)

Schuster, Andrea C.; Carl, Teresa; Foerster, Katharina

2017-04-01

Knowledge on animal personality has provided new insights into evolutionary biology and animal ecology, as behavioural types have been shown to affect fitness. Animal personality is characterized by repeatable and consistent between-individual behavioural differences throughout time and across different situations. Behavioural repeatability within life history stages and consistency between life history stages should be checked for the independence of sex and age, as recent data have shown that males and females in some species may differ in the repeatability of behavioural traits, as well as in their consistency. We measured the repeatability and consistency of three behavioural and one cognitive traits in juvenile and adult Eurasian harvest mice ( Micromys minutus). We found that exploration, activity and boldness were repeatable in juveniles and adults. Spatial recognition measured in a Y Maze was only repeatable in adult mice. Exploration, activity and boldness were consistent before and after maturation, as well as before and after first sexual contact. Data on spatial recognition provided little evidence for consistency. Further, we found some evidence for a litter effect on behaviours by comparing different linear mixed models. We concluded that harvest mice express animal personality traits as behaviours were repeatable across sexes and consistent across life history stages. The tested cognitive trait showed low repeatability and was less consistent across life history stages. Given the rising interest in individual variation in cognitive performance, and in its relationship to animal personality, we suggest that it is important to gather more data on the repeatability and consistency of cognitive traits.

Impaired long-term memory retention: common denominator for acutely or genetically reduced hippocampal neurogenesis in adult mice.

PubMed

Ben Abdallah, Nada M-B; Filipkowski, Robert K; Pruschy, Martin; Jaholkowski, Piotr; Winkler, Juergen; Kaczmarek, Leszek; Lipp, Hans-Peter

2013-09-01

In adult rodents, decreasing hippocampal neurogenesis experimentally using different approaches often impairs performance in hippocampus-dependent processes. Nonetheless, functional relevance of adult neurogenesis is far from being unraveled, and deficits so far described in animal models often lack reproducibility. One hypothesis is that such differences might be the consequence of the extent of the methodological specificity used to alter neurogenesis rather than the extent to which adult neurogenesis is altered. To address this, we focused on cranial irradiation, the most widely used technique to impair hippocampal neurogenesis and consequentially induce hippocampus-dependent behavioral deficits. To investigate the specificity of the technique, we thus exposed 4-5 months old female cyclin D2 knockout mice, a model lacking physiological levels of olfactory and hippocampal neurogenesis, to an X-ray dose of 10 Gy, reported to specifically affect transiently amplifying precursors. After a recovery period of 1.5 months, behavioral tests were performed and probed for locomotor activity, habituation, anxiety, and spatial learning and memory. Spatial learning in the Morris water maze was intact in all experimental groups. Although spatial memory retention assessed 24h following acquisition was also intact in all mice, irradiated wild type and cyclin D2 knockout mice displayed memory deficits one week after acquisition. In addition, we observed significant differences in tests addressing anxiety and locomotor activity dependent on the technique used to alter neurogenesis. Whereas irradiated mice were hyperactive regardless of their genotype, cyclin D2 knockout mice were hypoactive in most of the tests and displayed altered habituation. The present study emphasizes that different approaches aimed at decreasing adult hippocampal neurogenesis may result in distinct behavioral impairments related to locomotion and anxiety. In contrast, spatial long-term memory retention is

Functions of TAM RTKs in regulating spermatogenesis and male fertility in mice.

PubMed

Chen, Yongmei; Wang, Huizhen; Qi, Nan; Wu, Hui; Xiong, Weipeng; Ma, Jing; Lu, Qingxian; Han, Daishu

2009-10-01

Mice lacking TYRO3, AXL and MER (TAM) receptor tyrosine kinases (RTKs) are male sterile. The mechanism of TAM RTKs in regulating male fertility remains unknown. In this study, we analyzed in more detail the testicular phenotype of TAM triple mutant (TAM(-/-)) mice with an effort to understand the mechanism. We demonstrate that the three TAM RTKs cooperatively regulate male fertility, and MER appears to be more important than AXL and TYRO3. TAM(-/-) testes showed a progressive loss of germ cells from elongated spermatids to spermatogonia. Young adult TAM(-/-) mice exhibited oligo-astheno-teratozoospermia and various morphological malformations of sperm cells. As the mice aged, the germ cells were eventually depleted from the seminiferous tubules. Furthermore, we found that TAM(-/-) Sertoli cells have an impaired phagocytic activity and a large number of differentially expressed genes compared to wild-type controls. By contrast, the function of Leydig cells was not apparently affected by the mutation of TAM RTKs. Therefore, we conclude that the suboptimal function of Sertoli cells leads to the impaired spermatogenesis in TAM(-/-) mice. The results provide novel insight into the mechanism of TAM RTKs in regulating male fertility.

Regulation of GABAA and Glutamate Receptor Expression, Synaptic Facilitation and Long-Term Potentiation in the Hippocampus of Prion Mutant Mice

PubMed Central

Rangel, Alejandra; Madroñal, Noelia; Massó, Agnès Gruart i.; Gavín, Rosalina; Llorens, Franc; Sumoy, Lauro; Torres, Juan María; Delgado-García, José María; Río, José Antonio Del

2009-01-01

Background Prionopathies are characterized by spongiform brain degeneration, myoclonia, dementia, and periodic electroencephalographic (EEG) disturbances. The hallmark of prioniopathies is the presence of an abnormal conformational isoform (PrPsc) of the natural cellular prion protein (PrPc) encoded by the Prnp gene. Although several roles have been attributed to PrPc, its putative functions in neuronal excitability are unknown. Although early studies of the behavior of Prnp knockout mice described minor changes, later studies report altered behavior. To date, most functional PrPc studies on synaptic plasticity have been performed in vitro. To our knowledge, only one electrophysiological study has been performed in vivo in anesthetized mice, by Curtis and coworkers. They reported no significant differences in paired-pulse facilitation or LTP in the CA1 region after Schaffer collateral/commissural pathway stimulation. Methodology/Principal Findings Here we explore the role of PrPc expression in neurotransmission and neural excitability using wild-type, Prnp −/− and PrPc-overexpressing mice (Tg20 strain). By correlating histopathology with electrophysiology in living behaving mice, we demonstrate that both Prnp −/− mice but, more relevantly Tg20 mice show increased susceptibility to KA, leading to significant cell death in the hippocampus. This finding correlates with enhanced synaptic facilitation in paired-pulse experiments and hippocampal LTP in living behaving mutant mice. Gene expression profiling using Illumina™ microarrays and Ingenuity pathways analysis showed that 129 genes involved in canonical pathways such as Ubiquitination or Neurotransmission were co-regulated in Prnp −/− and Tg20 mice. Lastly, RT-qPCR of neurotransmission-related genes indicated that subunits of GABAA and AMPA-kainate receptors are co-regulated in both Prnp −/− and Tg20 mice. Conclusions/Significance Present results demonstrate that PrPc is necessary for the proper

Active site mutant transgene confers tolerance to human β-glucuronidase without affecting the phenotype of MPS VII mice

PubMed Central

Sly, William S.; Vogler, Carole; Grubb, Jeffrey H.; Zhou, Mi; Jiang, Jinxing; Zhou, Xiao Yan; Tomatsu, Shunji; Bi, Yanhua; Snella, Elizabeth M.

2001-01-01

Mucopolysaccharidosis type VII (MPS VII; Sly syndrome) is an autosomal recessive lysosomal storage disorder due to an inherited deficiency of β-glucuronidase. A naturally occurring mouse model for this disease was discovered at The Jackson Laboratory and shown to be due to homozygosity for a 1-bp deletion in exon 10 of the gus gene. The murine model MPS VII (gusmps/mps) has been very well characterized and used extensively to evaluate experimental strategies for lysosomal storage diseases, including bone marrow transplantation, enzyme replacement therapy, and gene therapy. To enhance the value of this model for enzyme and gene therapy, we produced a transgenic mouse expressing the human β-glucuronidase cDNA with an amino acid substitution at the active site nucleophile (E540A) and bred it onto the MPS VII (gusmps/mps) background. We demonstrate here that the mutant mice bearing the active site mutant human transgene retain the clinical, morphological, biochemical, and histopathological characteristics of the original MPS VII (gusmps/mps) mouse. However, they are now tolerant to immune challenge with human β-glucuronidase. This “tolerant MPS VII mouse model” should be useful for preclinical trials evaluating the effectiveness of enzyme and/or gene therapy with the human gene products likely to be administered to human patients with MPS VII. PMID:11226217

Apolipoprotein E4 reduces evoked hippocampal acetylcholine release in adult mice.

PubMed

Dolejší, Eva; Liraz, Ori; Rudajev, Vladimír; Zimčík, Pavel; Doležal, Vladimír; Michaelson, Daniel M

2016-02-01

Apolipoprotein E4 (apoE4) is the most prevalent genetic risk factor for Alzheimer's disease. We utilized apoE4-targeted replacement mice (approved by the Tel Aviv University Animal Care Committee) to investigate whether cholinergic dysfunction, which increases during aging and is a hallmark of Alzheimer's disease, is accentuated by apoE4. This revealed that levels of the pre-synaptic cholinergic marker, vesicular acetylcholine transporter in the hippocampus and the corresponding electrically evoked release of acetylcholine, are similar in 4-month-old apoE4 and apolipoprotein E3 (apoE3) mice. Both parameters decrease with age. This decrease is, however, significantly more pronounced in the apoE4 mice. The levels of cholinacetyltransferase (ChAT), acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) were similar in the hippocampus of young apoE4 and apoE3 mice and decreased during aging. For ChAT, this decrease was similar in the apoE4 and apoE3 mice, whereas it was more pronounced in the apoE4 mice, regarding their corresponding AChE and BuChE levels. The level of muscarinic receptors was higher in the apoE4 than in the apoE3 mice at 4 months and increased to similar levels with age. However, the relative representation of the M1 receptor subtype decreased during aging in apoE4 mice. These results demonstrate impairment of the evoked release of acetylcholine in hippocampus by apoE4 in 12-month-old mice but not in 4-month-old mice. The levels of ChAT and the extent of the M2 receptor-mediated autoregulation of ACh release were similar in the adult mice, suggesting that the apoE4-related inhibition of hippocampal ACh release in these mice is not driven by these parameters. Evoked ACh release from hippocampal and cortical slices is similar in 4-month-old apoE4 and apoE3 mice but is specifically and significantly reduced in hippocampus, but not cortex, of 12-month-old apoE4 mice. This effect is accompanied by decreased VAChT levels. These findings show that

Erythroblast differentiation at spleen in Q137E mutant ribosomal protein S19 gene knock-in C57BL/6J mice.

PubMed

Yamanegi, Koji; Yamada, Naoko; Nakasho, Keiji; Nishiura, Hiroshi

2018-01-01

We recently found that erythroblast-like cells derived from human leukaemia K562 cells express C5a receptor (C5aR) and produce its antagonistic and agonistic ligand ribosomal protein S19 (RP S19) polymer, which is cross-linked between K122 and Q137 by tissue transglutaminases. RP S19 polymer binds to the reciprocal C5aRs on erythroblast-like cells and macrophage-like cells derived from human monocytic THP-1 cells and promotes differentiation into reticulocyte-like cells through enucleation in vitro. To examine the roles of RP S19 polymer in mouse erythropoiesis, we prepared Q137E mutant RP S19 gene knock-in C57BL/6J mice. In contrast to wild-type mice, erythroblast numbers at the preliminary stage (CD71 high /TER119 low ) in spleen based on transferrin receptor (CD71) and glycophorin A (TER119) values and erythrocyte numbers in orbital artery bloods were not largely changed in knock-in mice. Conversely, erythroblast numbers at the early stage (CD71 high /TER119 high ) were significantly decreased in spleen by knock-in mice. The reduction of early erythroblast numbers in spleen was enhanced by the phenylhydrazine-induced pernicious anemia model knock-in mice and was rescued by a functional analogue of RP S19 dimer S-tagged C5a/RP S19. These data indicated that RP S19 polymer plays the roles in the early erythroblast differentiation of C57BL/6J mouse spleen. Copyright © 2017 Elsevier GmbH. All rights reserved.

Deletion of vanilloid receptor (TRPV1) in mice alters behavioral effects of ethanol

PubMed Central

Blednov, Y.A.; Harris, R.A.

2009-01-01

The vanilloid receptor TRPV1 is activated by ethanol and this may be important for some of the central and peripheral actions of ethanol. To determine if this receptor has a role in ethanol-mediated behaviors, we studied null mutant mice in which the Trpv1 gene was deleted. Mice lacking this gene showed significantly higher preference for ethanol and consumed more ethanol in a two-bottle choice test as compared with wild type littermates. Null mutant mice showed shorter duration of loss of righting reflex induced by low doses of ethanol (3.2 and 3.4 g/kg) and faster recovery from motor incoordination induced by ethanol (2 g/kg). However, there were no differences between null mutant and wild type mice in severity of ethanol-induced acute withdrawal (4 g/kg) or conditioned taste aversion to ethanol (2.5 g/kg). Two behavioral phenotypes (decreased sensitivity to ethanol-induced sedation and faster recovery from ethanol-induced motor incoordination) seen in null mutant mice were reproduced in wild type mice by injection of a TRPV1 antagonist, capsazepine (10 mg/kg). These two ethanol behaviors were changed in the opposite direction after injection of capsaicin, a selective TRPV1 agonist, in wild type mice. The studies provide the first evidence that TRPV1 is important for specific behavioral actions of ethanol. PMID:19705551

Antibody-directed myostatin inhibition improves diaphragm pathology in young but not adult dystrophic mdx mice.

PubMed

Murphy, Kate T; Ryall, James G; Snell, Sarah M; Nair, Lawrence; Koopman, René; Krasney, Philip A; Ibebunjo, Chikwendu; Holden, Kathryn S; Loria, Paula M; Salatto, Christopher T; Lynch, Gordon S

2010-05-01

Duchenne muscular dystrophy (DMD) is characterized by progressive skeletal muscle wasting and weakness, leading to premature death from respiratory and/or cardiac failure. A clinically relevant question is whether myostatin inhibition can improve function of the diaphragm, which exhibits a severe and progressive pathology comparable with that in DMD. We hypothesized that antibody-directed myostatin inhibition would improve the pathophysiology of diaphragm muscle strips from young mdx mice (when the pathology is mild) and adult mdx mice (when the pathology is quite marked). Five weeks treatment with a mouse chimera of anti-human myostatin antibody (PF-354, 10 mg/kg/week) increased muscle mass (P < 0.05) and increased diaphragm median fiber cross-sectional area (CSA, P < 0.05) in young C57BL/10 and mdx mice, compared with saline-treated controls. PF-354 had no effect on specific force (sPo, maximum force normalized to muscle CSA) of diaphragm muscle strips from young C57BL/10 mice, but increased sPo by 84% (P < 0.05) in young mdx mice. In contrast, 8 weeks of PF-354 treatment did not improve muscle mass, median fiber CSA, collagen infiltration, or sPo of diaphragm muscle strips from adult mdx mice. PF-354 antibody-directed myostatin inhibition completely restored the functional capacity of diaphragm strips to control levels when treatment was initiated early, but not in the later stages of disease progression, suggesting that such therapies may only have a limited window of efficacy for DMD and related conditions.

Existence of c-Kit negative cells with ultrastructural features of interstitial cells of Cajal in the subserosal layer of the W/Wv mutant mouse colon

PubMed Central

Tamada, Hiromi; Kiyama, Hiroshi

2015-01-01

Interstitial cells of Cajal (ICC) are mesenchymal cells that are distributed along the gastrointestinal tract and function as pacemaker cells or intermediary cells between nerves and smooth muscle cells. ICC express a receptor tyrosine kinase c-Kit, which is an established marker for ICC. The c-kit gene is allelic with the murine white-spotting locus (W), and some ICC subsets were reported to be missing in heterozygous mutant W/Wv mice carrying W and Wv mutated alleles. In this study, the characterization of interstitial cells in the subserosal layer of W/Wv mice was analyzed by immunohistochemistry and electron microscopy. In the proximal and distal colon of W/Wv mutant mice, no c-Kit-positive cells were detected in the subserosal layer by immunohistochemistry. By electron microscopy, the interstitial cells, which were characterized by the existence of caveolae, abundant mitochondria and gap junctions, were observed in the W/Wv mutant colon. The morphological characteristics were comparable to those of the multipolar c-Kit positive ICC seen in the subserosa of proximal and distal colon of wild-type mice. Fibroblasts were also located in the same layers, but the morphology of the fibroblasts was distinguishable from that of ICC in wild type mice or of ICC-like cells in W/Wv mutant mice. Collectively, it is concluded that c-Kit-negative interstitial cells showing a typical ICC ultrastructure exist in the proximal and distal colon of W/Wv mutant mice. PMID:26727725

Existence of c-Kit negative cells with ultrastructural features of interstitial cells of Cajal in the subserosal layer of the W/Wv mutant mouse colon.

PubMed

Tamada, Hiromi; Kiyama, Hiroshi

2015-01-01

Interstitial cells of Cajal (ICC) are mesenchymal cells that are distributed along the gastrointestinal tract and function as pacemaker cells or intermediary cells between nerves and smooth muscle cells. ICC express a receptor tyrosine kinase c-Kit, which is an established marker for ICC. The c-kit gene is allelic with the murine white-spotting locus (W), and some ICC subsets were reported to be missing in heterozygous mutant W/Wv mice carrying W and Wv mutated alleles. In this study, the characterization of interstitial cells in the subserosal layer of W/Wv mice was analyzed by immunohistochemistry and electron microscopy. In the proximal and distal colon of W/Wv mutant mice, no c-Kit-positive cells were detected in the subserosal layer by immunohistochemistry. By electron microscopy, the interstitial cells, which were characterized by the existence of caveolae, abundant mitochondria and gap junctions, were observed in the W/Wv mutant colon.The morphological characteristics were comparable to those of the multipolar c-Kit positive ICC seen in the subserosa of proximal and distal colon of wild-type mice. Fibroblasts were also located in the same layers,but the morphology of the fibroblasts was distinguishable from that of ICC in wild type mice or of ICC-like cells in W/Wv mutant mice. Collectively, it is concluded that c-Kit-negative interstitial cells showing a typical ICC ultrastructure exist in the proximal and distal colon of W/Wv mutant mice.

Adult Behavior in Male Mice Exposed to E-Cigarette Nicotine Vapors during Late Prenatal and Early Postnatal Life.

PubMed

Smith, Dani; Aherrera, Angela; Lopez, Armando; Neptune, Enid; Winickoff, Jonathan P; Klein, Jonathan D; Chen, Gang; Lazarus, Philip; Collaco, Joseph M; McGrath-Morrow, Sharon A

2015-01-01

Timed-pregnant C57BL/6J mice were exposed to 2.4% nicotine in propylene glycol (PG) or 0% nicotine /PG once a day from gestational day 15 until delivery. After delivery, offspring and mothers were exposed to E-cigarette vapors for an additional 14 days from postnatal day 2 through 16. Following their last exposure serum cotinine levels were measured in female juvenile mice. Male mice underwent behavioral testing at 14 weeks of age to assess sensorimotor, affective, and cognitive functional domains. Adult male mice exposed to 2.4% nicotine/PG E-cigarette vapors had significantly more head dips in the zero maze test and higher levels of rearing activity in the open field test compared to 0% nicotine/PG exposed mice and untreated controls. In the water maze test after reversal training, the 2.4% nicotine/PG mice spent more than 25% of time in the new location whereas the other groups did not. Adult male mice exhibited increased levels of activity in the zero maze and open field tests when exposed to E-cigarette vapor containing nicotine during late prenatal and early postnatal life. These findings indicate that nicotine exposure from E-cigarettes may cause persistent behavioral changes when exposure occurs during a period of rapid brain growth.

Short-Term Treatment with Bisphenol-A Leads to Metabolic Abnormalities in Adult Male Mice

PubMed Central

Batista, Thiago M.; Alonso-Magdalena, Paloma; Vieira, Elaine; Amaral, Maria Esmeria C.; Cederroth, Christopher R.; Nef, Serge; Quesada, Ivan; Carneiro, Everardo M.; Nadal, Angel

2012-01-01

Bisphenol-A (BPA) is one of the most widespread endocrine disrupting chemicals (EDC) used as the base compound in the manufacture of polycarbonate plastics. Although evidence points to consider exposure to BPA as a risk factor for insulin resistance, its actions on whole body metabolism and on insulin-sensitive tissues are still unclear. The aim of the present work was to study the effects of low doses of BPA in insulin-sensitive peripheral tissues and whole body metabolism in adult mice. Adult mice were treated with subcutaneous injection of 100 µg/kg BPA or vehicle for 8 days. Whole body energy homeostasis was assessed with in vivo indirect calorimetry. Insulin signaling assays were conducted by western blot analysis. Mice treated with BPA were insulin resistant and had increased glucose-stimulated insulin release. BPA-treated mice had decreased food intake, lower body temperature and locomotor activity compared to control. In skeletal muscle, insulin-stimulated tyrosine phosphorylation of the insulin receptor β subunit was impaired in BPA-treated mice. This impairment was associated with a reduced insulin-stimulated Akt phosphorylation in the Thr308 residue. Both skeletal muscle and liver displayed an upregulation of IRS-1 protein by BPA. The mitogen-activated protein kinase (MAPK) signaling pathway was also impaired in the skeletal muscle from BPA-treated mice. In the liver, BPA effects were of lesser intensity with decreased insulin-stimulated tyrosine phosphorylation of the insulin receptor β subunit. In conclusion, short-term treatment with low doses of BPA slows down whole body energy metabolism and disrupts insulin signaling in peripheral tissues. Thus, our findings support the notion that BPA can be considered a risk factor for the development of type 2 diabetes. PMID:22470480