Minocycline protects against lipopolysaccharide-induced cognitive impairment in mice.

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Hou, Yue; Xie, Guanbo; Liu, Xia; Li, Guoxun; Jia, Congcong; Xu, Jinghua; Wang, Bing

2016-03-01

The role of glial cells, especially microglia and astrocytes, in neuroinflammation and cognition has been studied intensively. Lipopolysaccharide (LPS), a commonly used inducer of neuroinflammation, can cause cognitive impairment. Minocycline is known to possess potent neuroprotective activity, but its effect on LPS-induced cognitive impairment is unknown. This study aims to investigate the effects of minocycline on LPS-induced cognitive impairment and glial cell activation in mice. Behavioral tests were conducted for cognitive function, immunohistochemistry for microglial and astrocyte response, and quantitative PCR for mRNA expression of proinflammatory cytokines. Minocycline significantly reversed the decreased spontaneous alternation induced by intrahippocampal administration of LPS in the Y-maze task. In the Morris water maze place navigation test, minocycline decreased the escape latency and distance traveled compared to LPS-treated mice. In the probe test, minocycline-treated mice spent more time in the target quadrant and crossed the platform area more frequently than animals in the LPS-treated group. Minocycline produced a significant decrease in the number of Iba-1- and GFAP-positive hippocampal cells compared to the LPS-treated group. Minocycline-treated mice had significantly reduced hippocampal TNF-α and IL-1β mRNA levels compared with LPS-treated animals. Minocycline caused a significant increase in hippocampal BDNF expression compared to the LPS-treated group. Minocycline can attenuate LPS-induced cognitive impairments in mice. This effect may be associated with its action to suppress the activation of microglia and astrocytes and to normalize BDNF expression. Since neuroinflammatory processes and cognitive impairments are implicated in neurodegenerative disorders, minocycline may be a promising candidate for treating such diseases.

Prenatal exposure to fenugreek impairs sensorimotor development and the operation of spinal cord networks in mice.

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Loubna Khalki

Full Text Available Fenugreek is a medicinal plant whose seeds are widely used in traditional medicine, mainly for its laxative, galactagogue and antidiabetic effects. However, consumption of fenugreek seeds during pregnancy has been associated with a range of congenital malformations, including hydrocephalus, anencephaly and spina bifida in humans. The present study was conducted to evaluate the effects of prenatal treatment of fenugreek seeds on the development of sensorimotor functions from birth to young adults. Pregnant mice were treated by gavage with 1 g/kg/day of lyophilized fenugreek seeds aqueous extract (FSAE or distilled water during the gestational period. Behavioral tests revealed in prenatally treated mice a significant delay in righting, cliff avoidance, negative geotaxis responses and the swimming development. In addition, extracellular recording of motor output in spinal cord isolated from neonatal mice showed that the frequency of spontaneous activity and fictive locomotion was reduced in FSAE-exposed mice. On the other hand, the cross-correlation coefficient in control mice was significantly more negative than in treated animals indicating that alternating patterns are deteriorated in FSAE-treated animals. At advanced age, prenatally treated mice displayed altered locomotor coordination in the rotarod test and also changes in static and dynamic parameters assessed by the CatWalk automated gait analysis system. We conclude that FSAE impairs sensorimotor and coordination functions not only in neonates but also in adult mice. Moreover, spinal neuronal networks are less excitable in prenatally FSAE-exposed mice suggesting that modifications within the central nervous system are responsible, at least in part, for the motor impairments.

Mice lacking collapsin response mediator protein 1 manifest hyperactivity, impaired learning and memory, and impaired prepulse inhibition

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Naoya eYamashita

2013-12-01

Full Text Available Collapsin response mediator protein 1 (CRMP1 is one of the CRMP family members that are involved in various aspects of neuronal development such as axonal guidance and neuronal migration. Here we provide evidence that crmp1-/- mice exhibited behavioral abnormalities related to schizophrenia. The crmp1-/- mice exhibited hyperactivity and/or impaired emotional behavioral phenotype. These mice also exhibited impaired context-dependent memory and long-term memory retention. Furthermore, crmp1-/- mice exhibited decreased prepulse inhibition, and this phenotype was rescued by administration of chlorpromazine, a typical antipsychotic drug. In addition, in vivo microdialysis revealed that the methamphetamine-induced release of dopamine in prefrontal cortex was exaggerated in crmp1-/- mice, suggesting that enhanced mesocortical dopaminergic transmission contributes to their hyperactivity phenotype. These observations suggest that impairment of CRMP1 function may be involved in the pathogenesis of schizophrenia. We propose that crmp1-/- mouse may model endophenotypes present in this neuropsychiatric disorder.

Prenatal exposure to arsenic impairs behavioral flexibility and cortical structure in mice

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Kyaw Htet eAung

2016-03-01

Full Text Available Exposure to arsenic from well water in developing countries is suspected to cause developmental neurotoxicity. Although it has been demonstrated that exposure to sodium arsenite (NaAsO2 suppresses neurite outgrowth of cortical neurons in vitro, it is largely unknown how developmental exposure to NaAsO2 impairs higher brain function and affects cortical histology. Here, we investigated the effect of prenatal NaAsO2 exposure on the behavior of mice in adulthood, and evaluated histological changes in the prelimbic cortex (PrL, which is a part of the medial prefrontal cortex that is critically involved in cognition. Drinking water with or without NaAsO2 (85 ppm was provided to pregnant C3H mice from gestational days 8 to 18, and offspring of both sexes were subjected to cognitive behavioral analyses at 60 weeks of age. The brains of female offspring were subsequently harvested and used for morphometrical analyses. We found that both male and female mice prenatally exposed to NaAsO2 displayed an impaired adaptation to repetitive reversal tasks. In morphometrical analyses of Nissl- or Golgi-stained tissue sections, we found that NaAsO2 exposure was associated with a significant increase in the number of pyramidal neurons in layers V and VI of the PrL, but not other layers of the PrL. More strikingly, prenatal NaAsO2 exposure was associated with a significant decrease in neurite length but not dendrite spine density in all layers of the PrL. Taken together, our results indicate that prenatal exposure to NaAsO2 leads to behavioral inflexibility in adulthood and cortical disarrangement in the PrL might contribute to this behavioral impairment.

Vascular Cognitive Impairment Linked to Brain Endothelium Inflammation in Early Stages of Heart Failure in Mice.

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Adamski, Mateusz G; Sternak, Magdalena; Mohaissen, Tasnim; Kaczor, Dawid; Wierońska, Joanna M; Malinowska, Monika; Czaban, Iwona; Byk, Katarzyna; Lyngsø, Kristina S; Przyborowski, Kamil; Hansen, Pernille B L; Wilczyński, Grzegorz; Chlopicki, Stefan

2018-03-26

Although advanced heart failure (HF) is a clinically documented risk factor for vascular cognitive impairment, the occurrence and pathomechanisms of vascular cognitive impairment in early stages of HF are equivocal. Here, we characterize vascular cognitive impairment in the early stages of HF development and assess whether cerebral hypoperfusion or prothrombotic conditions are involved. Tgαq*44 mice with slowly developing isolated HF triggered by cardiomyocyte-specific overexpression of G-αq*44 protein were studied before the end-stage HF, at the ages of 3, 6, and 10 months: before left ventricle dysfunction; at the stage of early left ventricle diastolic dysfunction (with preserved ejection fraction); and left ventricle diastolic/systolic dysfunction, respectively. In 6- to 10-month-old but not in 3-month-old Tgαq*44 mice, behavioral and cognitive impairment was identified with compromised blood-brain barrier permeability, most significantly in brain cortex, that was associated with myelin sheet loss and changes in astrocytes and microglia. Brain endothelial cells displayed increased E-selectin immunoreactivity, which was accompanied by increased amyloid-β 1-42 accumulation in piriform cortex and increased cortical oxidative stress (8-OHdG immunoreactivity). Resting cerebral blood flow measured by magnetic resonance imaging in vivo was preserved, but ex vivo NO-dependent cortical arteriole flow regulation was impaired. Platelet hyperreactivity was present in 3- to 10-month-old Tgαq*44 mice, but it was not associated with increased platelet-dependent thrombogenicity. We report for the first time that vascular cognitive impairment is already present in the early stage of HF development, even before left ventricle systolic dysfunction. The underlying pathomechanism, independent of brain hypoperfusion, involves preceding platelet hyperreactivity and brain endothelium inflammatory activation. © 2018 The Authors. Published on behalf of the American Heart

Preserved otolith organ function in caspase-3-deficient mice with impaired horizontal semicircular canal function.

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Armstrong, Patrick A; Wood, Scott J; Shimizu, Naoki; Kuster, Kael; Perachio, Adrian; Makishima, Tomoko

2015-06-01

Genetically engineered mice are valuable models for elucidation of auditory and vestibular pathology. Our goal was to establish a comprehensive vestibular function testing system in mice using: (1) horizontal angular vestibulo-ocular reflex (hVOR) to evaluate semicircular canal function and (2) otolith-ocular reflex (OOR) to evaluate otolith organ function and to validate the system by characterizing mice with vestibular dysfunction. We used pseudo off-vertical axis rotation to induce an otolith-only stimulus using a custom-made centrifuge. For the OOR, horizontal slow-phase eye velocity and vertical eye position were evaluated as a function of acceleration. Using this system, we characterized hVOR and OOR in the caspase-3 (Casp3) mutant mice. Casp3 (-/-) mice had severely impaired hVOR gain, while Casp3 (+/-) mice had an intermediate response compared to WT mice. Evaluation of OOR revealed that at low-to-mid frequencies and stimulus intensity, Casp3 mutants and WT mice had similar responses. At higher frequencies and stimulus intensity, the Casp3 mutants displayed mildly reduced otolith organ-related responses. These findings suggest that the Casp3 gene is important for the proper function of the semicircular canals but less important for the otolith organ function.

Preserved otolith organ function in caspase-3 deficient mice with impaired horizontal semicircular canal function

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Armstrong, Patrick A; Wood, Scott J; Shimizu, Naoki; Kuster, Kael; Perachio, Adrian; Makishima, Tomoko

2015-01-01

Genetically engineered mice are valuable models for elucidation of auditory and vestibular pathology. Our goal was to establish a comprehensive vestibular function testing system in mice using: 1) horizontal angular vestibular-ocular reflex (hVOR) to evaluate semicircular canal function, and 2) otolith-ocular reflex (OOR) to evaluate otolith organ function, and to validate the system by characterizing mice with vestibular dysfunction. We used pseudo-off vertical axis rotation (pOVAR) to induce an otolith-only stimulus using a custom-made centrifuge. For the OOR, horizontal slow phase eye velocity (HEV) and vertical eye position (VEP) was evaluated as a function of acceleration. Using this system, we characterized hVOR and OOR in the caspase-3 (Casp3) mutant mice. Casp3 −/− mice had severely impaired hVOR gain, while Casp3 +/− mice had an intermediate response compared to WT mice. Evaluation of OOR revealed that at low to mid frequencies and stimulus intensity, Casp3 mutants and WT mice had similar responses. At higher frequencies and stimulus intensity, the Casp3 mutants displayed mildly reduced otolith organ related responses. These findings suggest that the Casp3 gene is important for the proper function of the semicircular canals but less important for the otolith organ function. PMID:25827332

In Utero and Postnatal Propylthiouracil-Induced Mild Hypothyroidism Impairs Maternal Behavior in Mice

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Miski Aghnia Khairinisa

2018-05-01

Full Text Available Thyroid hormones (THs play crucial roles in general and brain development. Even if the hypothyroidism is mild, it may alter brain function, resulting in irreversible behavioral alterations. Although various behavioral analyses have been conducted, the effects of propylthiouracil (PTU treatment during in utero and postnatal periods on maternal behavior have not yet been studied. The present study examined in mice whether THs insufficiency during development induce behavioral changes. Pregnant C57BL/6j mice were divided into three groups, and each group was administered different dosages of PTU (0, 5, or 50 ppm in drinking water during in utero and postnatal periods (from gestational day 14 to postnatal day 21. First, locomotor activity and cognitive function were assessed in the offspring at 10 weeks. Next, female offspring were mated with normal mice and they and their offspring were used to assess several aspects of maternal behavior (identifying first pup, returning all pups to nest, time spent nursing, and licking pups. As expected, locomotor and cognitive functions in these mice were disrupted in a PTU dose-dependent manner. On postpartum day 2, dams who had been exposed 50 ppm PTU during in utero and postnatal periods displayed a significantly longer time identifying the first pup and returning all three pups back to the nest, less time nursing, and decreased licking behavior. The decrease in maternal behavior was significantly correlated with a decrease in cognition. These results indicate that insufficiency of THs during in utero and postnatal periods impairs maternal behavior, which may be partly induced by impaired cognitive function.

Impaired associative fear learning in mice with complete loss or haploinsufficiency of AMPA GluR1 receptors

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Michael Feyder

2007-12-01

Full Text Available There is compelling evidence that L-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA glutamate receptors containing the GluR1 subunit contribute to the molecular mechanisms associated with learning. AMPA GluR1 glutamate receptor knockout mice (KO exhibit abnormal hippocampal and amygdala plasticity, and deficits on various assays for cognition including Pavlovian fear conditioning. Here we examined associative fear learning in mice with complete absence (KO or partial loss (heterozygous mutant, HET of GluR1 on multiple fear conditioning paradigms. After multi-trial delay or trace conditioning, KO displayed impaired tone and context fear recall relative to WT, whereas HET were normal. After one-trial delay conditioning, both KO and HET showed impaired tone and context recall. HET and KO showed normal nociceptive sensitivity in the hot plate and tail flick tests. These data demonstrate that the complete absence of GluR1 subunit-containing receptors prevents the formation of associative fear memories, while GluR1 haploinsufficiency is sufficient to impair one-trial fear learning. These findings support growing evidence of a major role for GluR1-containing AMPA receptors in amygdalamediated forms of learning and memory.

Impaired receptivity and decidualization in DHEA-induced PCOS mice.

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Li, Shu-Yun; Song, Zhuo; Song, Min-Jie; Qin, Jia-Wen; Zhao, Meng-Long; Yang, Zeng-Ming

2016-12-07

Polycystic ovary syndrome (PCOS), a complex endocrine disorder, is a leading cause of female infertility. An obvious reason for infertility in PCOS women is anovulation. However, success rate with high quality embryos selected by assisted reproduction techniques in PCOS patients still remain low with a high rate of early clinical pregnancy loss, suggesting a problem in uterine receptivity. Using a dehydroepiandrosterone-induced mouse model of PCOS, some potential causes of decreased fertility in PCOS patients were explored. In our study, ovulation problem also causes sterility in PCOS mice. After blastocysts from normal mice are transferred into uterine lumen of pseudopregnant PCOS mice, the rate of embryo implantation was reduced. In PCOS mouse uteri, the implantation-related genes are also dysregulated. Additionally, artificial decidualization is severely impaired in PCOS mice. The serum estrogen level is significantly higher in PCOS mice than vehicle control. The high level of estrogen and potentially impaired LIF-STAT3 pathway may lead to embryo implantation failure in PCOS mice. Although there are many studies about effects of PCOS on endometrium, both embryo transfer and artificial decidualization are applied to exclude the effects from ovulation and embryos in our study.

Brain-specific Crmp2 deletion leads to neuronal development deficits and behavioural impairments in mice.

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Zhang, Hongsheng; Kang, Eunchai; Wang, Yaqing; Yang, Chaojuan; Yu, Hui; Wang, Qin; Chen, Zheyu; Zhang, Chen; Christian, Kimberly M; Song, Hongjun; Ming, Guo-Li; Xu, Zhiheng

2016-06-01

Several genome- and proteome-wide studies have associated transcription and translation changes of CRMP2 (collapsing response mediator protein 2) with psychiatric disorders, yet little is known about its function in the developing or adult mammalian brain in vivo. Here we show that brain-specific Crmp2 knockout (cKO) mice display molecular, cellular, structural and behavioural deficits, many of which are reminiscent of neural features and symptoms associated with schizophrenia. cKO mice exhibit enlarged ventricles and impaired social behaviour, locomotor activity, and learning and memory. Loss of Crmp2 in the hippocampus leads to reduced long-term potentiation, abnormal NMDA receptor composition, aberrant dendrite development and defective synapse formation in CA1 neurons. Furthermore, knockdown of crmp2 specifically in newborn neurons results in stage-dependent defects in their development during adult hippocampal neurogenesis. Our findings reveal a critical role for CRMP2 in neuronal plasticity, neural function and behavioural modulation in mice.

Gait disorder as a predictor of spatial learning and memory impairment in aged mice

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Xin Wang

2017-01-01

Full Text Available Objective To investigate whether gait dysfunction is a predictor of severe spatial learning and memory impairment in aged mice. Methods A total of 100 12-month-old male mice that had no obvious abnormal motor ability and whose Morris water maze performances were not significantly different from those of two-month-old male mice were selected for the study. The selected aged mice were then divided into abnormal or normal gait groups according to the results from the quantitative gait assessment. Gaits of aged mice were defined as abnormal when the values of quantitative gait parameters were two standard deviations (SD lower or higher than those of 2-month-old male mice. Gait parameters included stride length, variability of stride length, base of support, cadence, and average speed. After nine months, mice exhibiting severe spatial learning and memory impairment were separated from mice with mild or no cognitive dysfunction. The rate of severe spatial learning and memory impairment in the abnormal and normal gait groups was tested by a chi-square test and the correlation between gait dysfunction and decline in cognitive function was tested using a diagnostic test. Results The 12-month-old aged mice were divided into a normal gait group (n = 75 and an abnormal gait group (n = 25. Nine months later, three mice in the normal gait group and two mice in the abnormal gait group had died. The remaining mice were subjected to the Morris water maze again, and 17 out of 23 mice in the abnormal gait group had developed severe spatial learning and memory impairment, including six with stride length deficits, 15 with coefficient of variation (CV in stride length, two with base of support (BOS deficits, five with cadence dysfunction, and six with average speed deficits. In contrast, only 15 out of 72 mice in the normal gait group developed severe spatial learning and memory impairment. The rate of severe spatial learning and memory impairment was

Sleep deprivation impairs object recognition in mice

NARCIS (Netherlands)

Palchykova, S; Winsky-Sommerer, R; Meerlo, P; Durr, R; Tobler, Irene

2006-01-01

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in in object

Impaired cutaneous wound healing in mice lacking tetranectin

DEFF Research Database (Denmark)

Iba, Kousuke; Hatakeyama, Naoko; Kojima, Takashi

2009-01-01

disruption of the tetranectin gene to elucidate the biological function of tetranectin. In this study, we showed that wound healing was markedly delayed in tetranectin-null mice compared with wild-type mice. A single full-thickness incision was made in the dorsal skin. By 14 days after the incision......, the wounds fully healed in all wild-type mice based on the macroscopic closure; in contrast, the progress of wound healing in the tetranectin null mice appeared to be impaired. In histological analysis, wounds of wild-type mice showed complete reepithelialization and healed by 14 days after the incision....... However, those of tetranectin-null mice never showed complete reepithelialization at 14 days. At 21 days after the injury, the wound healed and was covered with an epidermis. These results supported the fact that tetranectin may play a role in the wound healing process....

Crybb2 deficiency impairs fertility in female mice

International Nuclear Information System (INIS)

Gao, Qian; Sun, Li-Li; Xiang, Fen-Fen; Gao, Li; Jia, Yin; Zhang, Jian-Rong; Tao, Hai-Bo; Zhang, Jun-Jie; Li, Wen-Jie

2014-01-01

Highlights: • Crybb2 deletion impaired female fertility. • Crybb2 deletion dramatically affected the production of reproduction-related hormones and hormone response. • Crybb2 deletion impaired follicular development and inhibited the proliferation of granulosa cells. • Crybb2 deletion promoted follicular atresia and apoptosis in granulosa cells. - Abstract: Beta-B2-crystallin (CRYBB2), encoded by Crybb2 gene, is a major protein in the mammalian eye lens that plays an important role in maintaining the transparency of the ocular lens. However, CRYBB2 also plays important roles in many extra-lenticular tissues and organs such as the retina, brain and testis. Our previous studies demonstrated that male Crybb2 deficient (Crybb2 −/− ) mice have reduced fertility compared with wild-type (WT) mice, while female Crybb2 −/− mice exhibited reduced ovary weights and shorter estrous cycle percentages. Here we specifically investigated the role of CRYBB2 in the female reproductive system. Our studies revealed that ovaries from female Crybb2 −/− mice exhibited significantly reduced numbers of primordial, secondary and pre-ovulatory follicles when compared with WT mice, while the rate of atretic follicles was also increased. Additionally, fewer eggs were collected from the oviduct of Crybb2 −/− female mice after superovulation. Estrogen levels were higher in the metestrus and diestrus cycles of female Crybb2 −/− mice, while progesterone levels were lower in diestrus cycles. Furthermore, the expression of survival and cell cycle genes, Bcl-2, Cdk4 and Ccnd2, were significantly decreased in granulosa cells isolated from female Crybb2 −/− mice, consistent with the predominant expression of CRYBB2 in ovarian granulosa cells. Our results reveal a critical role for CRYBB2 in female fertility and specific effects on the proliferation and survival status of ovarian granulosa cells

Crybb2 deficiency impairs fertility in female mice

Energy Technology Data Exchange (ETDEWEB)

Gao, Qian [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Sun, Li-Li [Aviation Medical Evaluation and Training Center of Airforce in Dalian, Dalian, Liaoning Province 116013 (China); Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Xiang, Fen-Fen [Department of Laboratory Medicine, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062 (China); Gao, Li [Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Jia, Yin; Zhang, Jian-Rong; Tao, Hai-Bo [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Zhang, Jun-Jie, E-mail: zhangjj910@163.com [Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Li, Wen-Jie, E-mail: wenjieli@pku.org.cn [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China)

2014-10-10

Highlights: • Crybb2 deletion impaired female fertility. • Crybb2 deletion dramatically affected the production of reproduction-related hormones and hormone response. • Crybb2 deletion impaired follicular development and inhibited the proliferation of granulosa cells. • Crybb2 deletion promoted follicular atresia and apoptosis in granulosa cells. - Abstract: Beta-B2-crystallin (CRYBB2), encoded by Crybb2 gene, is a major protein in the mammalian eye lens that plays an important role in maintaining the transparency of the ocular lens. However, CRYBB2 also plays important roles in many extra-lenticular tissues and organs such as the retina, brain and testis. Our previous studies demonstrated that male Crybb2 deficient (Crybb2{sup −/−}) mice have reduced fertility compared with wild-type (WT) mice, while female Crybb2{sup −/−} mice exhibited reduced ovary weights and shorter estrous cycle percentages. Here we specifically investigated the role of CRYBB2 in the female reproductive system. Our studies revealed that ovaries from female Crybb2{sup −/−} mice exhibited significantly reduced numbers of primordial, secondary and pre-ovulatory follicles when compared with WT mice, while the rate of atretic follicles was also increased. Additionally, fewer eggs were collected from the oviduct of Crybb2{sup −/−} female mice after superovulation. Estrogen levels were higher in the metestrus and diestrus cycles of female Crybb2{sup −/−} mice, while progesterone levels were lower in diestrus cycles. Furthermore, the expression of survival and cell cycle genes, Bcl-2, Cdk4 and Ccnd2, were significantly decreased in granulosa cells isolated from female Crybb2{sup −/−} mice, consistent with the predominant expression of CRYBB2 in ovarian granulosa cells. Our results reveal a critical role for CRYBB2 in female fertility and specific effects on the proliferation and survival status of ovarian granulosa cells.

Isoflurane-induced spatial memory impairment in mice is prevented by the acetylcholinesterase inhibitor donepezil.

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Diansan Su

Full Text Available Although many studies have shown that isoflurane exposure impairs spatial memory in aged animals, there are no clinical treatments available to prevent this memory deficit. The anticholinergic properties of volatile anesthetics are a biologically plausible cause of cognitive dysfunction in elderly subjects. We hypothesized that pretreatment with the acetylcholinesterase inhibitor donepezil, which has been approved by the Food and Drug Administration (FDA for the treatment of Alzheimer's disease, prevents isoflurane-induced spatial memory impairment in aged mice. In present study, eighteen-month-old mice were administered donepezil (5 mg/kg or an equal volume of saline by oral gavage with a feeding needle for four weeks. Then the mice were exposed to isoflurane (1.2% for six hours. Two weeks later, mice were subjected to the Morris water maze to examine the impairment of spatial memory after exposure to isoflurane. After the behavioral test, the mice were sacrificed, and the protein expression level of acetylcholinesterase (AChE, choline acetylase (ChAT and α7 nicotinic receptor (α7-nAChR were measured in the brain. Each group consisted of 12 mice. We found that isoflurane exposure for six hours impaired the spatial memory of the mice. Compared with the control group, isoflurane exposure dramatically decreased the protein level of ChAT, but not AChE or α7-nAChR. Donepezil prevented isoflurane-induced spatial memory impairments and increased ChAT levels, which were downregulated by isoflurane. In conclusions, pretreatment with the AChE inhibitor donepezil prevented isoflurane-induced spatial memory impairment in aged mice. The mechanism was associated with the upregulation of ChAT, which was decreased by isoflurane.

Altered hippocampal replay is associated with memory impairment in mice heterozygous for the Scn2a gene.

Science.gov (United States)

Middleton, Steven J; Kneller, Emily M; Chen, Shuo; Ogiwara, Ikuo; Montal, Mauricio; Yamakawa, Kazuhiro; McHugh, Thomas J

2018-06-04

An accumulating body of experimental evidence has implicated hippocampal replay occurring within sharp wave ripples (SPW-Rs) as crucial for learning and memory in healthy subjects. This raises speculation that neurological disorders impairing memory disrupt either SPW-Rs or their underlying neuronal activity. We report that mice heterozygous for the gene Scn2a, a site of frequent de novo mutations in humans with intellectual disability, displayed impaired spatial memory. While we observed no changes during encoding, to either single place cells or cell assemblies, we identified abnormalities restricted to SPW-R episodes that manifest as decreased cell assembly reactivation strengths and truncated hippocampal replay sequences. Our results suggest that alterations to hippocampal replay content may underlie disease-associated memory deficits.

Altered thermogenesis and impaired bone remodeling in Misty mice.

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Motyl, Katherine J; Bishop, Kathleen A; DeMambro, Victoria E; Bornstein, Sheila A; Le, Phuong; Kawai, Masanobu; Lotinun, Sutada; Horowitz, Mark C; Baron, Roland; Bouxsein, Mary L; Rosen, Clifford J

2013-09-01

Fat mass may be modulated by the number of brown-like adipocytes in white adipose tissue (WAT) in humans and rodents. Bone remodeling is dependent on systemic energy metabolism and, with age, bone remodeling becomes uncoupled and brown adipose tissue (BAT) function declines. To test the interaction between BAT and bone, we employed Misty (m/m) mice, which were reported be deficient in BAT. We found that Misty mice have accelerated age-related trabecular bone loss and impaired brown fat function (including reduced temperature, lower expression of Pgc1a, and less sympathetic innervation compared to wild-type (+/ +)). Despite reduced BAT function, Misty mice had normal core body temperature, suggesting heat is produced from other sources. Indeed, upon acute cold exposure (4°C for 6 hours), inguinal WAT from Misty mice compensated for BAT dysfunction by increasing expression of Acadl, Pgc1a, Dio2, and other thermogenic genes. Interestingly, acute cold exposure also decreased Runx2 and increased Rankl expression in Misty bone, but only Runx2 was decreased in wild-type. Browning of WAT is under the control of the sympathetic nervous system (SNS) and, if present at room temperature, could impact bone metabolism. To test whether SNS activity could be responsible for accelerated trabecular bone loss, we treated wild-type and Misty mice with the β-blocker, propranolol. As predicted, propranolol slowed trabecular bone volume/total volume (BV/TV) loss in the distal femur of Misty mice without affecting wild-type. Finally, the Misty mutation (a truncation of DOCK7) also has a significant cell-autonomous role. We found DOCK7 expression in whole bone and osteoblasts. Primary osteoblast differentiation from Misty calvaria was impaired, demonstrating a novel role for DOCK7 in bone remodeling. Despite the multifaceted effects of the Misty mutation, we have shown that impaired brown fat function leads to altered SNS activity and bone loss, and for the first time that cold

Impairments in cognition and neural precursor cell proliferation in mice expressing constitutively active glycogen synthase kinase-3

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Marta ePardo

2015-03-01

Full Text Available ABSTRACTBrain glycogen synthase kinase-3 (GSK3 is hyperactive in several neurological conditions that involve impairments in both cognition and neurogenesis. This raises the hypotheses that hyperactive GSK3 may directly contribute to impaired cognition, and that this may be related to deficiencies in neural precursor cells (NPC. To study the effects of hyperactive GSK3 in the absence of disease influences, we compared adult hippocampal NPC proliferation and performance in three cognitive tasks in male and female wild-type mice and GSK3 knockin mice, which express constitutively active GSK3. NPC proliferation was ~40% deficient in both male and female GSK3 knockin mice compared with wild-type mice. Environmental enrichment (EE increased NPC proliferation in male, but not female, GSK3 knockin mice and wild-type mice. Male and female GSK3 knockin mice exhibited impairments in novel object recognition, temporal order memory, and coordinate spatial processing compared with gender-matched wild-type mice. EE restored impaired novel object recognition and temporal ordering in both sexes of GSK3 knockin mice, indicating that this repair was not dependent on NPC proliferation, which was not increased by EE in female GSK3 knockin mice. Acute 1 hr pretreatment with the GSK3 inhibitor TDZD-8 also improved novel object recognition and temporal ordering in male and female GSK3 knockin mice. These findings demonstrate that hyperactive GSK3 is sufficient to impair adult hippocampal NPC proliferation and to impair performance in three cognitive tasks in both male and female mice, but these changes in NPC proliferation do not directly regulate novel object recognition and temporal ordering tasks.

Impaired transport of thyroid hormones into livers of obese (ob/ob) mice

International Nuclear Information System (INIS)

Hillgartner, F.B.; Romsos, D.R.

1988-01-01

Obese (ob/ob) mice exhibit impaired hepatic thyroid hormone action that is mediated, at least in part, by a reduced nuclear 3,5,3'-triiodothyronine (T 3 ) receptor occupancy. The possibility that lowered occupancy in obese mice may be caused by decreased transport of T 3 across the hepatic plasma membrane was examined by measuring the unidirectional influx of [ 125 I]T 3 into livers of 8- to 10-wk-old obese and lean mice using a tissue-sampling portal vein-injection technique. Influx of [ 125 I]thyroxine (T 4 ), a substrate for T 4 5'-deiodinase, was also measured. Unidirectional clearance of T 3 and T 4 was 64 and 80% lower, respectively, in obese mice than in lean mice. Hepatic T 3 and T 4 uptake was nonsaturable in both lean and obese mice, suggesting that transport occurs by lipid-mediated free diffusion. Clearance of another lipid-soluble hormone, hydrocortisone, was also lower in obese mice than in lean mice. Decreased membrane permeability to the above hormones in obese mice may result from reported changes in membrane lipid composition. In conclusion, decreased hepatic thyroid hormone uptake may contribute to impaired thyroid hormone action and T 3 production in livers of obese mice

Hippocampal expression of a virus-derived protein impairs memory in mice.

Science.gov (United States)

Bétourné, Alexandre; Szelechowski, Marion; Thouard, Anne; Abrial, Erika; Jean, Arnaud; Zaidi, Falek; Foret, Charlotte; Bonnaud, Emilie M; Charlier, Caroline M; Suberbielle, Elsa; Malnou, Cécile E; Granon, Sylvie; Rampon, Claire; Gonzalez-Dunia, Daniel

2018-02-13

The analysis of the biology of neurotropic viruses, notably of their interference with cellular signaling, provides a useful tool to get further insight into the role of specific pathways in the control of behavioral functions. Here, we exploited the natural property of a viral protein identified as a major effector of behavioral disorders during infection. We used the phosphoprotein (P) of Borna disease virus, which acts as a decoy substrate for protein kinase C (PKC) when expressed in neurons and disrupts synaptic plasticity. By a lentiviral-based strategy, we directed the singled-out expression of P in the dentate gyrus of the hippocampus and we examined its impact on mouse behavior. Mice expressing the P protein displayed increased anxiety and impaired long-term memory in contextual and spatial memory tasks. Interestingly, these effects were dependent on P protein phosphorylation by PKC, as expression of a mutant form of P devoid of its PKC phosphorylation sites had no effect on these behaviors. We also revealed features of behavioral impairment induced by P protein expression but that were independent of its phosphorylation by PKC. Altogether, our findings provide insight into the behavioral correlates of viral infection, as well as into the impact of virus-mediated alterations of the PKC pathway on behavioral functions.

Abnormal brain iron metabolism in Irp2 deficient mice is associated with mild neurological and behavioral impairments.

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Kimberly B Zumbrennen-Bullough

Full Text Available Iron Regulatory Protein 2 (Irp2, Ireb2 is a central regulator of cellular iron homeostasis in vertebrates. Two global knockout mouse models have been generated to explore the role of Irp2 in regulating iron metabolism. While both mouse models show that loss of Irp2 results in microcytic anemia and altered body iron distribution, discrepant results have drawn into question the role of Irp2 in regulating brain iron metabolism. One model shows that aged Irp2 deficient mice develop adult-onset progressive neurodegeneration that is associated with axonal degeneration and loss of Purkinje cells in the central nervous system. These mice show iron deposition in white matter tracts and oligodendrocyte soma throughout the brain. A contrasting model of global Irp2 deficiency shows no overt or pathological signs of neurodegeneration or brain iron accumulation, and display only mild motor coordination and balance deficits when challenged by specific tests. Explanations for conflicting findings in the severity of the clinical phenotype, brain iron accumulation and neuronal degeneration remain unclear. Here, we describe an additional mouse model of global Irp2 deficiency. Our aged Irp2-/- mice show marked iron deposition in white matter and in oligodendrocytes while iron content is significantly reduced in neurons. Ferritin and transferrin receptor 1 (TfR1, Tfrc, expression are increased and decreased, respectively, in the brain from Irp2-/- mice. These mice show impairments in locomotion, exploration, motor coordination/balance and nociception when assessed by neurological and behavioral tests, but lack overt signs of neurodegenerative disease. Ultrastructural studies of specific brain regions show no evidence of neurodegeneration. Our data suggest that Irp2 deficiency dysregulates brain iron metabolism causing cellular dysfunction that ultimately leads to mild neurological, behavioral and nociceptive impairments.

Impaired baroreflex function in mice overexpressing alpha-synuclein

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Sheila eFleming

2013-07-01

Full Text Available Cardiovascular autonomic dysfunction, such as orthostatic hypotension consequent to baroreflex failure and cardiac sympathetic denervation, is frequently observed in the synucleinopathy Parkinson’s disease (PD. In the present study, the baroreceptor reflex was assessed in mice overexpressing human wildtype alpha-synuclein (Thy1-aSyn, a genetic mouse model of synucleinopathy. The beat-to-beat change in heart rate, computed from R-R interval, in relation to blood pressure was measured in anesthetized and conscious mice equipped with arterial blood pressure telemetry transducers during transient bouts of hypertension and hypotension. Compared to wildtype, tachycardia following nitroprusside-induced hypotension was significantly reduced in Thy1-aSyn mice. Thy1-aSyn mice also showed an abnormal cardiovascular response (i.e., diminished tachycardia to muscarinic blockade with atropine. We conclude that Thy1-aSyn mice have impaired basal and dynamic range of sympathetic and parasympathetic-mediated changes in heart rate and will be a useful model for long-term study of cardiovascular autonomic dysfunction associated with PD.

Apolipoprotein E*3-Leiden transgenic mice mode for hypolipidaemic drugs

NARCIS (Netherlands)

Vlijmen, B.J.M. van; Pearce, N.J.; Bergö, M.; Staels, B.; Yates, J.W.; Gribble, A.D.; Bond, B.C.; Hofker, M.H.; Havekes, L.M.; Groot, P.H.E.

1998-01-01

Apolipoprotein (APO) E*3-Leiden mice with impaired chylomicron and VLDL (very low density lipoprotein) remnant metabolism display hyperlipidaemia and atherosclerosis. In the present study, these mice were used for testing the hypolipidaemic effect of two marketed agents, lovastatin (CAS 75330-75-5)

Deletion of Lkb1 in pro-opiomelanocortin neurons impairs peripheral glucose homeostasis in mice.

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Claret, Marc; Smith, Mark A; Knauf, Claude; Al-Qassab, Hind; Woods, Angela; Heslegrave, Amanda; Piipari, Kaisa; Emmanuel, Julian J; Colom, André; Valet, Philippe; Cani, Patrice D; Begum, Ghazala; White, Anne; Mucket, Phillip; Peters, Marco; Mizuno, Keiko; Batterham, Rachel L; Giese, K Peter; Ashworth, Alan; Burcelin, Remy; Ashford, Michael L; Carling, David; Withers, Dominic J

2011-03-01

AMP-activated protein kinase (AMPK) signaling acts as a sensor of nutrients and hormones in the hypothalamus, thereby regulating whole-body energy homeostasis. Deletion of Ampkα2 in pro-opiomelanocortin (POMC) neurons causes obesity and defective neuronal glucose sensing. LKB1, the Peutz-Jeghers syndrome gene product, and Ca(2+)-calmodulin-dependent protein kinase kinase β (CaMKKβ) are key upstream activators of AMPK. This study aimed to determine their role in POMC neurons upon energy and glucose homeostasis regulation. Mice lacking either Camkkβ or Lkb1 in POMC neurons were generated, and physiological, electrophysiological, and molecular biology studies were performed. Deletion of Camkkβ in POMC neurons does not alter energy homeostasis or glucose metabolism. In contrast, female mice lacking Lkb1 in POMC neurons (PomcLkb1KO) display glucose intolerance, insulin resistance, impaired suppression of hepatic glucose production, and altered expression of hepatic metabolic genes. The underlying cellular defect in PomcLkb1KO mice involves a reduction in melanocortin tone caused by decreased α-melanocyte-stimulating hormone secretion. However, Lkb1-deficient POMC neurons showed normal glucose sensing, and body weight was unchanged in PomcLkb1KO mice. Our findings demonstrate that LKB1 in hypothalamic POMC neurons plays a key role in the central regulation of peripheral glucose metabolism but not body-weight control. This phenotype contrasts with that seen in mice lacking AMPK in POMC neurons with defects in body-weight regulation but not glucose homeostasis, which suggests that LKB1 plays additional functions distinct from activating AMPK in POMC neurons.

Female preproenkephalin-knockout mice display altered emotional responses

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Ragnauth, A.; Schuller, A.; Morgan, M.; Chan, J.; Ogawa, S.; Pintar, J.; Bodnar, R. J.; Pfaff, D. W.

2001-01-01

The endogenous opioid system has been implicated in sexual behavior, palatable intake, fear, and anxiety. The present study examined whether ovariectomized female transgenic preproenkephalin-knockout (PPEKO) mice and their wild-type and heterozygous controls displayed alterations in fear and anxiety paradigms, sucrose intake, and lordotic behavior. To examine stability of responding, three squads of the genotypes were tested across seasons over a 20-month period. In a fear-conditioning paradigm, PPEKO mice significantly increased freezing to both fear and fear + shock stimuli relative to controls. In the open field, PPEKO mice spent significantly less time and traversed significantly less distance in the center of an open field than wild-type controls. Further, PPEKO mice spent significantly less time and tended to be less active on the light side of a dark–light chamber than controls, indicating that deletion of the enkephalin gene resulted in exaggerated responses to fear or anxiety-provoking environments. These selective deficits were observed consistently across testing squads spanning 20 months and different seasons. In contrast, PPEKO mice failed to differ from corresponding controls in sucrose, chow, or water intake across a range (0.0001–20%) of sucrose concentrations and failed to differ in either lordotic or female approach to male behaviors when primed with estradiol and progesterone, thereby arguing strongly for the selectivity of a fear and anxiety deficit which was not caused by generalized and nonspecific debilitation. These transgenic data strongly suggest that opioids, and particularly enkephalin gene products, are acting naturally to inhibit fear and anxiety. PMID:11172058

Running performance at high running velocities is impaired but V'O(₂max and peripheral endothelial function are preserved in IL-6⁻/⁻ mice.

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Marta Wojewoda

Full Text Available It has been reported that IL-6 knockout mice (IL-6⁻/⁻ possess lower endurance capacity than wild type mice (WT, however the underlying mechanism is poorly understood. The aim of the present work was to examine whether reduced endurance running capacity in IL-6⁻/⁻ mice is linked to impaired maximal oxygen uptake (V'O(₂max, decreased glucose tolerance, endothelial dysfunction or other mechanisms. Maximal running velocity during incremental running to exhaustion was significantly lower in IL-6⁻/⁻ mice than in WT mice (13.00±0.97 m·min⁻¹ vs. 16.89±1.15 m·min⁻¹, P<0.02, respectively. Moreover, the time to exhaustion during running at 12 m·min⁻¹ in IL-6⁻/⁻ mice was significantly shorter (P<0.05 than in WT mice. V'O(₂max in IL-6⁻/⁻ (n = 20 amounting to 108.3±2.8 ml·kg⁻¹·min⁻¹ was similar as in WT mice (n = 22 amounting to 113.0±1.8 ml·kg⁻¹·min⁻¹, (P = 0.16. No difference in maximal COX activity between the IL-6⁻/⁻ and WT mice in m. soleus and m. gastrocnemius was found. Moreover, no impairment of peripheral endothelial function or glucose tolerance was found in IL-6⁻/⁻ mice. Surprisingly, plasma lactate concentration during running at 8 m·min⁻¹ as well at maximal running velocity in IL-6⁻/⁻ mice was significantly lower (P<0.01 than in WT mice. Interestingly, IL-6⁻/⁻ mice displayed important adaptive mechanisms including significantly lower oxygen cost of running at a given speed accompanied by lower expression of sarcoplasmic reticulum Ca²⁺-ATPase and lower plasma lactate concentrations during running at submaximal and maximal running velocities. In conclusion, impaired endurance running capacity in IL-6⁻/⁻ mice could not be explained by reduced V'O(₂max, endothelial dysfunction or impaired muscle oxidative capacity. Therefore, our results indicate that IL-6 cannot be regarded as a major regulator of exercise capacity but rather as a modulator of endurance

Running performance at high running velocities is impaired but V'O(₂max) and peripheral endothelial function are preserved in IL-6⁻/⁻ mice.

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Wojewoda, Marta; Kmiecik, Katarzyna; Ventura-Clapier, Renée; Fortin, Dominique; Onopiuk, Marta; Jakubczyk, Justyna; Sitek, Barbara; Fedorowicz, Andrzej; Majerczak, Joanna; Kaminski, Karol; Chlopicki, Stefan; Zoladz, Jerzy Andrzej

2014-01-01

It has been reported that IL-6 knockout mice (IL-6⁻/⁻) possess lower endurance capacity than wild type mice (WT), however the underlying mechanism is poorly understood. The aim of the present work was to examine whether reduced endurance running capacity in IL-6⁻/⁻ mice is linked to impaired maximal oxygen uptake (V'O(₂max)), decreased glucose tolerance, endothelial dysfunction or other mechanisms. Maximal running velocity during incremental running to exhaustion was significantly lower in IL-6⁻/⁻ mice than in WT mice (13.00±0.97 m·min⁻¹ vs. 16.89±1.15 m·min⁻¹, P<0.02, respectively). Moreover, the time to exhaustion during running at 12 m·min⁻¹ in IL-6⁻/⁻ mice was significantly shorter (P<0.05) than in WT mice. V'O(₂max) in IL-6⁻/⁻ (n = 20) amounting to 108.3±2.8 ml·kg⁻¹·min⁻¹ was similar as in WT mice (n = 22) amounting to 113.0±1.8 ml·kg⁻¹·min⁻¹, (P = 0.16). No difference in maximal COX activity between the IL-6⁻/⁻ and WT mice in m. soleus and m. gastrocnemius was found. Moreover, no impairment of peripheral endothelial function or glucose tolerance was found in IL-6⁻/⁻ mice. Surprisingly, plasma lactate concentration during running at 8 m·min⁻¹ as well at maximal running velocity in IL-6⁻/⁻ mice was significantly lower (P<0.01) than in WT mice. Interestingly, IL-6⁻/⁻ mice displayed important adaptive mechanisms including significantly lower oxygen cost of running at a given speed accompanied by lower expression of sarcoplasmic reticulum Ca²⁺-ATPase and lower plasma lactate concentrations during running at submaximal and maximal running velocities. In conclusion, impaired endurance running capacity in IL-6⁻/⁻ mice could not be explained by reduced V'O(₂max), endothelial dysfunction or impaired muscle oxidative capacity. Therefore, our results indicate that IL-6 cannot be regarded as a major regulator of exercise capacity but rather as a modulator of endurance

Running Performance at High Running Velocities Is Impaired but V′O2max and Peripheral Endothelial Function Are Preserved in IL-6−/− Mice

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Wojewoda, Marta; Kmiecik, Katarzyna; Ventura-Clapier, Renée; Fortin, Dominique; Onopiuk, Marta; Jakubczyk, Justyna; Sitek, Barbara; Fedorowicz, Andrzej; Majerczak, Joanna; Kaminski, Karol; Chlopicki, Stefan; Zoladz, Jerzy Andrzej

2014-01-01

It has been reported that IL-6 knockout mice (IL-6−/−) possess lower endurance capacity than wild type mice (WT), however the underlying mechanism is poorly understood. The aim of the present work was to examine whether reduced endurance running capacity in IL-6−/− mice is linked to impaired maximal oxygen uptake (V′O2max), decreased glucose tolerance, endothelial dysfunction or other mechanisms. Maximal running velocity during incremental running to exhaustion was significantly lower in IL-6−/− mice than in WT mice (13.00±0.97 m.min−1 vs. 16.89±1.15 m.min−1, P<0.02, respectively). Moreover, the time to exhaustion during running at 12 m.min−1 in IL-6−/− mice was significantly shorter (P<0.05) than in WT mice. V′O2max in IL-6−/− (n = 20) amounting to 108.3±2.8 ml.kg−1.min−1 was similar as in WT mice (n = 22) amounting to 113.0±1.8 ml.kg−1.min−1, (P = 0.16). No difference in maximal COX activity between the IL-6−/− and WT mice in m. soleus and m. gastrocnemius was found. Moreover, no impairment of peripheral endothelial function or glucose tolerance was found in IL-6−/− mice. Surprisingly, plasma lactate concentration during running at 8 m.min−1 as well at maximal running velocity in IL-6−/− mice was significantly lower (P<0.01) than in WT mice. Interestingly, IL-6−/− mice displayed important adaptive mechanisms including significantly lower oxygen cost of running at a given speed accompanied by lower expression of sarcoplasmic reticulum Ca2+-ATPase and lower plasma lactate concentrations during running at submaximal and maximal running velocities. In conclusion, impaired endurance running capacity in IL-6−/− mice could not be explained by reduced V′O2max, endothelial dysfunction or impaired muscle oxidative capacity. Therefore, our results indicate that IL-6 cannot be regarded as a major regulator of exercise capacity but rather as a modulator of endurance performance. Furthermore, we

Exercise Training Reverses Extrapulmonary Impairments in Smoke-exposed Mice.

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Bowen, T Scott; Aakerøy, Lars; Eisenkolb, Sophia; Kunth, Patricia; Bakkerud, Fredrik; Wohlwend, Martin; Ormbostad, Anne Marie; Fischer, Tina; Wisloff, Ulrik; Schuler, Gerhard; Steinshamn, Sigurd; Adams, Volker; Bronstad, Eivind

2017-05-01

Cigarette smoking is the main risk factor for chronic obstructive pulmonary disease and emphysema. However, evidence on the extrapulmonary effects of smoke exposure that precede lung impairments remains unclear at present, as are data on nonpharmacological treatments such as exercise training. Three groups of mice, including control (n = 10), smoking (n = 10), and smoking with 6 wk of high-intensity interval treadmill running (n = 11), were exposed to 20 wk of fresh air or whole-body cigarette smoke. Exercise capacity (peak oxygen uptake) and lung destruction (histology) were subsequently measured, whereas the heart, peripheral endothelium (aorta), and respiratory (diaphragm) and limb (extensor digitorum longus and soleus) skeletal muscles were assessed for in vivo and in vitro function, in situ mitochondrial respiration, and molecular alterations. Smoking reduced body weight by 26% (P 0.05). Smoking impaired exercise capacity by 15% while inducing right ventricular dysfunction by ~20%, endothelial dysfunction by ~20%, and diaphragm muscle weakness by ~15% (all P exercise training (P smoking mice had normal limb muscle and mitochondrial function (cardiac and skeletal muscle fibers); however, diaphragm measures of oxidative stress and protein degradation were increased by 111% and 65%, respectively (P exercise training (P smoking reduced exercise capacity concomitant with functional impairments to the heart, peripheral endothelium, and respiratory muscle that preceded the development of overt emphysema. However, high-intensity exercise training was able to reverse these smoke-induced extrapulmonary impairments.

Mice deficient in phosphodiesterase-4A display anxiogenic-like behavior.

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Hansen, Rolf T; Conti, Marco; Zhang, Han-Ting

2014-08-01

Phosphodiesterases (PDEs) are a super family of enzymes responsible for the halting of intracellular cyclic nucleotide signaling and may represent novel therapeutic targets for treatment of cognitive disorders. PDE4 is of considerable interest to cognitive research because it is highly expressed in the brain, particularly in the cognition-related brain regions. Recently, the functional role of PDE4B and PDE4D, two of the four PDE4 subtypes (PDE4A, B, C, and D), in behavior has begun to be identified; however, the role of PDE4A in the regulation of behavior is still unknown. The purpose of this study was to characterize the functional role of PDE4A in behavior. The role of PDE4A in behavior was evaluated through a battery of behavioral tests using PDE4A knockout (KO) mice; urine corticosterone levels were also measured. PDE4A KO mice exhibited improved memory in the step-through-passive-avoidance test. They also displayed anxiogenic-like behavior in elevated-plus maze, holeboard, light-dark transition, and novelty suppressed feeding tests. Consistent with the anxiety profile, PDE4A KO mice had elevated corticosterone levels compared with wild-type controls post-stress. Interestingly, PDE4A KO mice displayed no change in object recognition, Morris water maze, forced swim, tail suspension, and duration of anesthesia induced by co-administration of xylazine and ketamine (suggesting that PDE4A KO may not be emetic). These results suggest that PDE4A may be important in the regulation of emotional memory and anxiety-like behavior, but not emesis. PDE4A could possibly represent a novel therapeutic target in the future for anxiety or disorders affecting memory.

Deletion of PEA-15 in mice is associated with specific impairments of spatial learning abilities

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Hale Gregory

2009-11-01

Full Text Available Abstract Background PEA-15 is a phosphoprotein that binds and regulates ERK MAP kinase and RSK2 and is highly expressed throughout the brain. PEA-15 alters c-Fos and CREB-mediated transcription as a result of these interactions. To determine if PEA-15 contributes to the function of the nervous system we tested mice lacking PEA-15 in a series of experiments designed to measure learning, sensory/motor function, and stress reactivity. Results We report that PEA-15 null mice exhibited impaired learning in three distinct spatial tasks, while they exhibited normal fear conditioning, passive avoidance, egocentric navigation, and odor discrimination. PEA-15 null mice also had deficient forepaw strength and in limited instances, heightened stress reactivity and/or anxiety. However, these non-cognitive variables did not appear to account for the observed spatial learning impairments. The null mice maintained normal weight, pain sensitivity, and coordination when compared to wild type controls. Conclusion We found that PEA-15 null mice have spatial learning disabilities that are similar to those of mice where ERK or RSK2 function is impaired. We suggest PEA-15 may be an essential regulator of ERK-dependent spatial learning.

Impaired neuronal maturation of hippocampal neural progenitor cells in mice lacking CRAF.

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Pfeiffer, Verena; Götz, Rudolf; Camarero, Guadelupe; Heinsen, Helmut; Blum, Robert; Rapp, Ulf Rüdiger

2018-01-01

RAF kinases are major constituents of the mitogen activated signaling pathway, regulating cell proliferation, differentiation and cell survival of many cell types, including neurons. In mammals, the family of RAF proteins consists of three members, ARAF, BRAF, and CRAF. Ablation of CRAF kinase in inbred mouse strains causes major developmental defects during fetal growth and embryonic or perinatal lethality. Heterozygous germline mutations in CRAF result in Noonan syndrome, which is characterized by neurocognitive impairment that may involve hippocampal physiology. The role of CRAF signaling during hippocampal development and generation of new postnatal hippocampal granule neurons has not been examined and may provide novel insight into the cause of hippocampal dysfunction in Noonan syndrome. In this study, by crossing CRAF-deficiency to CD-1 outbred mice, a CRAF mouse model was established which enabled us to investigate the interplay of neural progenitor proliferation and postmitotic differentiation during adult neurogenesis in the hippocampus. Albeit the general morphology of the hippocampus was unchanged, CRAF-deficient mice displayed smaller granule cell layer (GCL) volume at postnatal day 30 (P30). In CRAF-deficient mice a substantial number of abnormal, chromophilic, fast dividing cells were found in the subgranular zone (SGZ) and hilus of the dentate gyrus (DG), indicating that CRAF signaling contributes to hippocampal neural progenitor proliferation. CRAF-deficient neural progenitor cells showed an increased cell death rate and reduced neuronal maturation. These results indicate that CRAF function affects postmitotic neural cell differentiation and points to a critical role of CRAF-dependent growth factor signaling pathway in the postmitotic development of adult-born neurons.

Neuroprotective effect of curcumin on okadaic acid induced memory impairment in mice.

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Rajasekar, N; Dwivedi, Subhash; Tota, Santosh Kumar; Kamat, Pradeep Kumar; Hanif, Kashif; Nath, Chandishwar; Shukla, Rakesh

2013-09-05

Okadaic acid (OKA) has been observed to cause memory impairment in human subjects having seafood contaminated with dinoflagellate (Helicondria okadai). OKA induces tau hyperphosphorylation and oxidative stress leading to memory impairment as our previous study has shown. Curcumin a natural antioxidant has demonstrated neuroprotection in various models of neurodegeneration. However, the effect of curcumin has not been explored in OKA induced memory impairment. Therefore, present study evaluated the effect of curcumin on OKA (100ng, intracerebrally) induced memory impairment in male Swiss albino mice as evaluated in Morris water maze (MWM) and passive avoidance tests (PAT). OKA administration resulted in memory impairment with a decreased cerebral blood flow (CBF) (measured by laser doppler flowmetry), ATP level and increased mitochondrial (Ca(2+))i, neuroinflammation (increased TNF-α, IL-1β, COX-2 and GFAP), oxidative-nitrosative stress, increased Caspase-9 and cholinergic dysfunction (decreased AChE activity/expression and α7 nicotinic acetylcholine receptor expression) in cerebral cortex and hippocampus of mice brain. Oral administration of curcumin (50mg/kg) for 13 days significantly improved memory function in both MWM and PAT along with brain energy metabolism, CBF and cholinergic function. It decreased mitochondrial (Ca(2+))i, and ameliorated neuroinflammation and oxidative-nitrostative stress in different brain regions of OKA treated mice. Curcumin also inhibited astrocyte activation as evidenced by decreased GFAP expression. This neuroprotective effect of curcumin is due to its potent anti-oxidant action thus confirming previous studies. Therefore, use of curcumin should be encouraged in people consuming sea food (contaminated with dinoflagellates) to prevent cognitive impairment. © 2013 Elsevier B.V. All rights reserved.

Deletion of Lkb1 in Pro-Opiomelanocortin Neurons Impairs Peripheral Glucose Homeostasis in Mice

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Claret, Marc; Smith, Mark A.; Knauf, Claude; Al-Qassab, Hind; Woods, Angela; Heslegrave, Amanda; Piipari, Kaisa; Emmanuel, Julian J.; Colom, André; Valet, Philippe; Cani, Patrice D.; Begum, Ghazala; White, Anne; Mucket, Phillip; Peters, Marco; Mizuno, Keiko; Batterham, Rachel L.; Giese, K. Peter; Ashworth, Alan; Burcelin, Remy; Ashford, Michael L.; Carling, David; Withers, Dominic J.

2011-01-01

OBJECTIVE AMP-activated protein kinase (AMPK) signaling acts as a sensor of nutrients and hormones in the hypothalamus, thereby regulating whole-body energy homeostasis. Deletion of Ampkα2 in pro-opiomelanocortin (POMC) neurons causes obesity and defective neuronal glucose sensing. LKB1, the Peutz-Jeghers syndrome gene product, and Ca2+-calmodulin–dependent protein kinase kinase β (CaMKKβ) are key upstream activators of AMPK. This study aimed to determine their role in POMC neurons upon energy and glucose homeostasis regulation. RESEARCH DESIGN AND METHODS Mice lacking either Camkkβ or Lkb1 in POMC neurons were generated, and physiological, electrophysiological, and molecular biology studies were performed. RESULTS Deletion of Camkkβ in POMC neurons does not alter energy homeostasis or glucose metabolism. In contrast, female mice lacking Lkb1 in POMC neurons (PomcLkb1KO) display glucose intolerance, insulin resistance, impaired suppression of hepatic glucose production, and altered expression of hepatic metabolic genes. The underlying cellular defect in PomcLkb1KO mice involves a reduction in melanocortin tone caused by decreased α-melanocyte–stimulating hormone secretion. However, Lkb1-deficient POMC neurons showed normal glucose sensing, and body weight was unchanged in PomcLkb1KO mice. CONCLUSIONS Our findings demonstrate that LKB1 in hypothalamic POMC neurons plays a key role in the central regulation of peripheral glucose metabolism but not body-weight control. This phenotype contrasts with that seen in mice lacking AMPK in POMC neurons with defects in body-weight regulation but not glucose homeostasis, which suggests that LKB1 plays additional functions distinct from activating AMPK in POMC neurons. PMID:21266325

Synaptic plasticity in the hippocampus of a APP/PS1 mouse model of Alzheimer's disease is impaired in old but not young mice.

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Simon Gengler

Full Text Available BACKGROUND: Alzheimer disease (AD is a neurodegenerative disorder for which there is no cure. We have investigated synaptic plasticity in area CA1 in a novel AD mouse model (APPPS1-21 which expresses the Swedish mutation of APP and the L166P mutation of human PS-1. This model shows initial plaque formation at 2 months in the neocortex and 4 months in the hippocampus and displays beta-amyloid-associated pathologies and learning impairments. METHODOLOGY/PRINCIPAL FINDINGS: We tested long-term potentiation (LTP and short term potentiation (paired-pulse facilitation, PPF of synaptic transmission in vivo in area CA1 of the hippocampus. There was no difference in LTP or PPF at 4-5 months of age in APPPS1-21 mice compared to littermate controls. At 6 months of age there was also no difference in LTP but APPPS1-21 mice showed slightly increased PPF (p<0.03. In 8 months old mice, LTP was greatly impaired in APPPS-21 animals (p<0.0001 while PPF was not changed. At 15 months of age, APPPS1-21 mice showed again impaired LTP compared to littermate controls (p<0.005, and PPF was also significantly reduced at 80 ms (p<0.005 and 160 ms (p<0.01 interstimulus interval. Immunohistological analysis showed only modest amyloid deposition in the hippocampus at 4 and 6 months with a robust increase up to 15 months of age. CONCLUSIONS: Our results suggest that increased formation and aggregation of beta amyloid with aging is responsible for the impaired LTP with aging in this mouse model, while the transient increase of PPF at 6 months of age is caused by some other mechanism.

Chronic exposure to low frequency noise at moderate levels causes impaired balance in mice.

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Haruka Tamura

Full Text Available We are routinely exposed to low frequency noise (LFN; below 0.5 kHz at moderate levels of 60-70 dB sound pressure level (SPL generated from various sources in occupational and daily environments. LFN has been reported to affect balance in humans. However, there is limited information about the influence of chronic exposure to LFN at moderate levels for balance. In this study, we investigated whether chronic exposure to LFN at a moderate level of 70 dB SPL affects the vestibule, which is one of the organs responsible for balance in mice. Wild-type ICR mice were exposed for 1 month to LFN (0.1 kHz and high frequency noise (HFN; 16 kHz at 70 dB SPL at a distance of approximately 10-20 cm. Behavior analyses including rotarod, beam-crossing and footprint analyses showed impairments of balance in LFN-exposed mice but not in non-exposed mice or HFN-exposed mice. Immunohistochemical analysis showed a decreased number of vestibular hair cells and increased levels of oxidative stress in LFN-exposed mice compared to those in non-exposed mice. Our results suggest that chronic exposure to LFN at moderate levels causes impaired balance involving morphological impairments of the vestibule with enhanced levels of oxidative stress. Thus, the results of this study indicate the importance of considering the risk of chronic exposure to LFN at a moderate level for imbalance.

Cordyceps militaris extract attenuates D-galactose-induced memory impairment in mice.

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Li, Zaixin; Zhang, Zhi; Zhang, Jinshan; Jia, Jing; Ding, Jie; Luo, Rongzhen; Liu, Zhangqin

2012-12-01

Memory impairment is one of main clinical symptoms of brain senescence. To address the effects of Cordyceps militaris Link extract (CE) on memory impairment, a D-galactose (D-Gal)-induced aging mouse model was employed. Mice injected with D-Gal showed a significant learning and memory impairment that was rescued by CE treatment. The mechanism was further investigated by analyzing the protein level and activity of oxidant and antioxidant molecules, including malondialdehyde (MDA), monoamine oxidase (MAO), total super-oxide dismutase (T-SOD), total antioxidant capacity (T-AOC), glutathione (GSH), and glutathione peroxidase (GSH-px), which played critical roles in the development of brain senescence. The results showed that CE treatment resulted in a significant decrease in the oxidative activity of MAO and the level of MDA, and significantly increased the antioxidant activities of T-SOD and T-AOC in the cerebral cortices. Moreover, the level of GSH and the activity of antioxidant enzymes GSH-px in serum were significantly upregulated after CE treatment. Taken together, our results suggest that Cordyceps militaris extract could ameliorate experimental memory impairment in mice with D-Gal-induced aging through its potent antioxidant activities.

Loss of CDKL5 in Glutamatergic Neurons Disrupts Hippocampal Microcircuitry and Leads to Memory Impairment in Mice.

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Tang, Sheng; Wang, I-Ting Judy; Yue, Cuiyong; Takano, Hajime; Terzic, Barbara; Pance, Katarina; Lee, Jun Y; Cui, Yue; Coulter, Douglas A; Zhou, Zhaolan

2017-08-02

Cyclin-dependent kinase-like 5 (CDKL5) deficiency is a neurodevelopmental disorder characterized by epileptic seizures, severe intellectual disability, and autistic features. Mice lacking CDKL5 display multiple behavioral abnormalities reminiscent of the disorder, but the cellular origins of these phenotypes remain unclear. Here, we find that ablating CDKL5 expression specifically from forebrain glutamatergic neurons impairs hippocampal-dependent memory in male conditional knock-out mice. Hippocampal pyramidal neurons lacking CDKL5 show decreased dendritic complexity but a trend toward increased spine density. This morphological change is accompanied by an increase in the frequency of spontaneous miniature EPSCs and interestingly, miniature IPSCs. Using voltage-sensitive dye imaging to interrogate the evoked response of the CA1 microcircuit, we find that CA1 pyramidal neurons lacking CDKL5 show hyperexcitability in their dendritic domain that is constrained by elevated inhibition in a spatially and temporally distinct manner. These results suggest a novel role for CDKL5 in the regulation of synaptic function and uncover an intriguing microcircuit mechanism underlying impaired learning and memory. SIGNIFICANCE STATEMENT Cyclin-dependent kinase-like 5 (CDKL5) deficiency is a severe neurodevelopmental disorder caused by mutations in the CDKL5 gene. Although Cdkl5 constitutive knock-out mice have recapitulated key aspects of human symptomatology, the cellular origins of CDKL5 deficiency-related phenotypes are unknown. Here, using conditional knock-out mice, we show that hippocampal-dependent learning and memory deficits in CDKL5 deficiency have origins in glutamatergic neurons of the forebrain and that loss of CDKL5 results in the enhancement of synaptic transmission and disruptions in neural circuit dynamics in a spatially and temporally specific manner. Our findings demonstrate that CDKL5 is an important regulator of synaptic function in glutamatergic neurons and

Anesthesia and Surgery Impair Blood–Brain Barrier and Cognitive Function in Mice

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Yang, Siming; Gu, Changping; Mandeville, Emiri T.; Dong, Yuanlin; Esposito, Elga; Zhang, Yiying; Yang, Guang; Shen, Yuan; Fu, Xiaobing; Lo, Eng H.; Xie, Zhongcong

2017-01-01

Blood–brain barrier (BBB) dysfunction, e.g., increase in BBB permeability, has been reported to contribute to cognitive impairment. However, the effects of anesthesia and surgery on BBB permeability, the underlying mechanisms, and associated cognitive function remain largely to be determined. Here, we assessed the effects of surgery (laparotomy) under 1.4% isoflurane anesthesia (anesthesia/surgery) for 2 h on BBB permeability, levels of junction proteins and cognitive function in both 9- and 18-month-old wild-type mice and 9-month-old interleukin (IL)-6 knockout mice. BBB permeability was determined by dextran tracer (immunohistochemistry imaging and spectrophotometric quantification), and protein levels were measured by Western blot and cognitive function was assessed by using both Morris water maze and Barnes maze. We found that the anesthesia/surgery increased mouse BBB permeability to 10-kDa dextran, but not to 70-kDa dextran, in an IL-6-dependent and age-associated manner. In addition, the anesthesia/surgery induced an age-associated increase in blood IL-6 level. Cognitive impairment was detected in 18-month-old, but not 9-month-old, mice after the anesthesia/surgery. Finally, the anesthesia/surgery decreased the levels of β-catenin and tight junction protein claudin, occludin and ZO-1, but not adherent junction protein VE-cadherin, E-cadherin, and p120-catenin. These data demonstrate that we have established a system to study the effects of perioperative factors, including anesthesia and surgery, on BBB and cognitive function. The results suggest that the anesthesia/surgery might induce an age-associated BBB dysfunction and cognitive impairment in mice. These findings would promote mechanistic studies of postoperative cognitive impairment, including postoperative delirium. PMID:28848542

Anesthesia and Surgery Impair Blood–Brain Barrier and Cognitive Function in Mice

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Siming Yang

2017-08-01

Full Text Available Blood–brain barrier (BBB dysfunction, e.g., increase in BBB permeability, has been reported to contribute to cognitive impairment. However, the effects of anesthesia and surgery on BBB permeability, the underlying mechanisms, and associated cognitive function remain largely to be determined. Here, we assessed the effects of surgery (laparotomy under 1.4% isoflurane anesthesia (anesthesia/surgery for 2 h on BBB permeability, levels of junction proteins and cognitive function in both 9- and 18-month-old wild-type mice and 9-month-old interleukin (IL-6 knockout mice. BBB permeability was determined by dextran tracer (immunohistochemistry imaging and spectrophotometric quantification, and protein levels were measured by Western blot and cognitive function was assessed by using both Morris water maze and Barnes maze. We found that the anesthesia/surgery increased mouse BBB permeability to 10-kDa dextran, but not to 70-kDa dextran, in an IL-6-dependent and age-associated manner. In addition, the anesthesia/surgery induced an age-associated increase in blood IL-6 level. Cognitive impairment was detected in 18-month-old, but not 9-month-old, mice after the anesthesia/surgery. Finally, the anesthesia/surgery decreased the levels of β-catenin and tight junction protein claudin, occludin and ZO-1, but not adherent junction protein VE-cadherin, E-cadherin, and p120-catenin. These data demonstrate that we have established a system to study the effects of perioperative factors, including anesthesia and surgery, on BBB and cognitive function. The results suggest that the anesthesia/surgery might induce an age-associated BBB dysfunction and cognitive impairment in mice. These findings would promote mechanistic studies of postoperative cognitive impairment, including postoperative delirium.

D-Aspartate drinking solution alleviates pain and cognitive impairment in neuropathic mice.

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Palazzo, Enza; Luongo, Livio; Guida, Francesca; Marabese, Ida; Romano, Rosaria; Iannotta, Monica; Rossi, Francesca; D'Aniello, Antimo; Stella, Luigi; Marmo, Federica; Usiello, Alessandro; de Bartolomeis, Andrea; Maione, Sabatino; de Novellis, Vito

2016-07-01

D-Aspartate (D-Asp) is a free D-amino acid detected in multiple brain regions and putative precursor of endogenous N-methyl-D-aspartate (NMDA) acting as agonist at NMDA receptors. In this study, we investigated whether D-Asp (20 mM) in drinking solution for 1 month affects pain responses and pain-related emotional, and cognitive behaviour in a model of neuropathic pain induced by the spared nerve injury (SNI) of the sciatic nerve in mice. SNI mice developed mechanical allodynia and motor coordination impairment 30 days after SNI surgery. SNI mice showed cognitive impairment, anxiety and depression-like behaviour, reduced sociability in the three chamber sociability paradigm, increased expression of NR2B subunit of NMDA receptor and Homer 1a in the medial prefrontal cortex (mPFC). The expression of (post synaptic density) PSD-95 and Shank 1was instead unaffected in the mPFC of the SNI mice. Treatment with D-Asp drinking solution, started right after the SNI (day 0), alleviated mechanical allodynia, improved cognition and motor coordination and increased social interaction. D-Asp also restored the levels of extracellular D-Asp, Homer 1a and NR2B subunit of the NMDA receptor to physiological levels and reduced Shank1 and PSD-95 protein levels in the mPFC. Amitriptyline, a tricyclic antidepressant used also to alleviate neuropathic pain in humans, reverted mechanical allodynia and cognitive impairment, and unlike D-Asp, was effective in reducing depression and anxiety-like behaviour in the SNI mice and increased PSD protein level. Altogether these findings demonstrate that D-Asp improves sensorial, motor and cognitive-like symptoms related to chronic pain possibly through glutamate neurotransmission normalization in neuropathic mice.

Host-microbiota interaction induces bi-phasic inflammation and glucose intolerance in mice

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Molinaro, Antonio; Caesar, Robert; Holm, Louise Mannerås

2017-01-01

expansion and inflammation. Importantly, re-colonization of antibiotic treated mice displays only the delayed phase of glucose impairment and adiposity, suggesting that the early phase may be unique to colonization of the immature GF mice gut. CONCLUSIONS: Our results provide new insights on host...

Akt2/LDLr double knockout mice display impaired glucose tolerance and develop more complex atherosclerotic plaques than LDLr knockout mice

NARCIS (Netherlands)

Rensing, Katrijn L.; de Jager, Saskia C. A.; Stroes, Erik S.; Vos, Mariska; Twickler, Marcel Th B.; Dallinga-Thie, Geesje M.; de Vries, Carlie J. M.; Kuiper, Johan; Bot, Ilze; von der Thüsen, Jan H.

2014-01-01

To characterize the phenotype of Akt2/low-density-lipoprotein receptor double knockout (dKO) (Akt2/LDLr dKO) mice with respect to insulin resistance and features of atherosclerotic plaque progression. Metabolic profile and atherosclerotic plaque progression were compared between LDLr KO mice and

Insulin signaling displayed a differential tissue-specific response to low-dose dihydrotestosterone in female mice.

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Andrisse, Stanley; Billings, Katelyn; Xue, Ping; Wu, Sheng

2018-04-01

Hyperandrogenemia and hyperinsulinemia are believed to play prominent roles in polycystic ovarian syndrome (PCOS). We explored the effects of low-dose dihydrotestosterone (DHT), a model of PCOS, on insulin signaling in metabolic and reproductive tissues in a female mouse model. Insulin resistance in the energy storage tissues is associated with type 2 diabetes. Insulin signaling in the ovaries and pituitary either directly or indirectly stimulates androgen production. Energy storage and reproductive tissues were isolated and molecular assays were performed. Livers and white adipose tissue (WAT) from DHT mice displayed lower mRNA and protein expression of insulin signaling intermediates. However, ovaries and pituitaries of DHT mice exhibited higher expression levels of insulin signaling genes/proteins. Insulin-stimulated p-AKT levels were blunted in the livers and WAT of the DHT mice but increased or remained the same in the ovaries and pituitaries compared with controls. Glucose uptake decreased in liver and WAT but was unchanged in pituitary and ovary of DHT mice. Plasma membrane GLUTs were decreased in liver and WAT but increased in ovary and pituitary of DHT mice. Skeletal muscle insulin-signaling genes were not lowered in DHT mice compared with control. DHT mice did not display skeletal muscle insulin resistance. Insulin-stimulated glucose transport increased in skeletal muscles of DHT mice compared with controls. DHT mice were hyperinsulinemic. However, the differential mRNA and protein expression pattern was independent of hyperinsulinemia in cultured hepatocytes and pituitary cells. These findings demonstrate a differential effect of DHT on the insulin-signaling pathway in energy storage vs. reproductive tissues independent of hyperinsulinemia.

Lactobacillus salivarius reverse diabetes-induced intestinal defense impairment in mice through non-defensin protein.

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Chung, Pei-Hsuan; Wu, Ying-Ying; Chen, Pei-Hsuan; Fung, Chang-Phone; Hsu, Ching-Mei; Chen, Lee-Wei

2016-09-01

Altered intestinal microbiota and subsequent endotoxemia play pathogenic roles in diabetes. We aimed to study the mechanisms of intestinal defense impairment in type 1 diabetes and the effects of Lactobacillus salivarius as well as fructooligosaccharides (FOS) supplementation on diabetes-induced bacterial translocation. Alterations in the enteric microbiome, expression of mucosal antibacterial proteins and bacteria-killing activity of the intestinal mucosa in streptozotocin (STZ)-induced diabetic mice and Ins2(Akita) mice were investigated. The effects of dead L. salivarius (2×10(8)CFU/ml) and FOS (250 mg per day) supplementation for 1 week on endotoxin levels and Klebsiella pneumoniae translocation were also examined. Finally, germ-free mice were cohoused with wild-type or Ins2(Akita) mice for 2 weeks to examine the contribution of microbiota on the antibacterial protein expression. STZ-induced diabetic mice developed intestinal defense impairment as demonstrated by decreased mucosal bacteria-killing activity; reduction of non-defensin family proteins, such as Reg3β, Reg3γ, CRP-ductin and RELMβ, but not the defensin family proteins; and increased bacterial translocation. Intestinal bacteria overgrowth, enteric dysbiosis and increased intestinal bacterial translocation, particularly pathogenic K. pneumoniae in STZ-induced diabetic mice and Ins2(Akita) mice, were noted. Treating diabetic mice with dead L. salivarius or FOS reversed enteric dysbiosis, restored mucosal antibacterial protein and lessened endotoxin levels as well as K. pneumoniae translocation. Moreover, germ-free mice cohoused with wild-type mice demonstrated more intestinal Reg3β and RELMβ expression than those cohoused with Ins2(Akita) mice. These results indicate that hyperglycemia induces enteric dysbiosis, reduction of non-defensin proteins as well as bacteria-killing activity of the intestinal mucosa and intestinal defense impairment. Reversal of enteric dysbiosis with dead L. salivarius or

Impaired Sperm Maturation in Rnase9 Knockout Mice1

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Westmuckett, Andrew D.; Nguyen, Edward B.; Herlea-Pana, Oana M.; Alvau, Antonio; Salicioni, Ana M.; Moore, Kevin L.

2014-01-01

ABSTRACT Ribonuclease, RNase A family, 9 (RNASE9) is a ribonuclease A superfamily member that is expressed only in the epididymis. It is a small, secreted polypeptide, it lacks ribonuclease activity, and its function(s) is unknown. However, epididymis-specific expression suggests a role in sperm maturation. We generated Rnase9−/− mice to study RNASE9 function in vivo. We confirm that RNASE9 expression is restricted to the epididymis. Within the epididymis, RNASE9 is first detected in midcaput, persists through the distal caput and corpus, and wanes in the cauda. Rnase9−/− mice are born at the expected Mendelian ratio, have normal postnatal growth and development, and have no outwardly apparent phenotype. Spermatogenesis is normal, and Rnase9-null sperm are morphologically normal. Rnase9−/− males have normal fertility in unrestricted mating trials, and fertilization rates in in vitro fertilization assays are indistinguishable from wild-type mice. Visual observations coupled with analyses of sperm velocities shortly after swim out from the corpus shows that motility of Rnase9-null sperm is significantly impaired. However, no differences between wild-type and Rnase9-null sperm are detected by computer-assisted sperm analysis 10–90 min after sperm isolation from the corpus or cauda. Assessment of capacitation-dependent signaling pathways in Rnase9-null sperm showed that, while levels of tyrosine phosphorylation of sperm proteins were normal, there was decreased phosphorylation of protein kinase A substrates upon capacitation compared to wild-type mice. In conclusion, RNASE9 is dispensable for fertility, but the absence of RNASE9 during epididymal transit results in impaired sperm maturation. PMID:24719258

Moringa oleifera Seed Extract Alleviates Scopolamine-Induced Learning and Memory Impairment in Mice

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Juan Zhou

2018-04-01

Full Text Available The extract of Moringa oleifera seeds has been shown to possess various pharmacological properties. In the present study, we assessed the neuropharmacological effects of 70% ethanolic M. oleifera seed extract (MSE on cognitive impairment caused by scopolamine injection in mice using the passive avoidance and Morris water maze (MWM tests. MSE (250 or 500 mg/kg was administered to mice by oral gavage for 7 or 14 days, and cognitive impairment was induced by intraperitoneal injection of scopolamine (4 mg/kg for 1 or 6 days. Mice that received scopolamine alone showed impaired learning and memory retention and considerably decreased cholinergic system reactivity and neurogenesis in the hippocampus. MSE pretreatment significantly ameliorated scopolamine-induced cognitive impairment and enhanced cholinergic system reactivity and neurogenesis in the hippocampus. Additionally, the protein expressions of phosphorylated Akt, ERK1/2, and CREB in the hippocampus were significantly decreased by scopolamine, but these decreases were reversed by MSE treatment. These results suggest that MSE-induced ameliorative cognitive effects are mediated by enhancement of the cholinergic neurotransmission system and neurogenesis via activation of the Akt, ERK1/2, and CREB signaling pathways. These findings suggest that MSE could be a potent neuropharmacological drug against amnesia, and its mechanism might be modulation of cholinergic activity via the Akt, ERK1/2, and CREB signaling pathways.

Mice with deleted multimerin 1 and alpha-synuclein genes have impaired platelet adhesion and impaired thrombus formation that is corrected by multimerin 1.

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Reheman, Adili; Tasneem, Subia; Ni, Heyu; Hayward, Catherine P M

2010-05-01

Multimerin 1 is a stored platelet and endothelial cell adhesive protein that shows significant conservation. In vitro, multimerin 1 supports platelet adhesion and it also binds to collagen and enhances von Willebrand factor-dependent platelet adhesion to collagen. As selective, multimerin 1 deficient mice have not been generated, we investigated multimerin 1 effects on platelet adhesion using a subpopulation of C57BL/6J mice with tandem deletion of the genes for multimerin 1 and alpha-synuclein, a protein that inhibits alpha-granule release in vitro. We postulated that multimerin 1/alpha-synuclein deficient mice might show impaired platelet adhesive function from multimerin 1 deficiency and increased alpha-granule release from alpha-synuclein deficiency. Platelet function was assessed by intravital microscopy, after ferric chloride injury, using untreated and human multimerin 1-transfused multimerin 1/alpha-synuclein deficient mice, and by in vitro assays of adhesion, aggregation and thrombin-induced P-selectin release. Multimerin 1/alpha-synuclein deficient mice showed impaired platelet adhesion and their defective thrombus formation at sites of vessel injury improved with multimerin 1 transfusion. Although multimerin 1/alpha-synuclein deficient platelets showed increased P-selectin release at low thrombin concentrations, they also showed impaired adhesion to collagen, and attenuated aggregation with thrombin, that improved with added multimerin 1. Our data suggest that multimerin 1 supports platelet adhesive functions and thrombus formation, which will be important to verify by generating and testing selective multimerin 1 deficient mice. Copyright (c) 2010. Published by Elsevier Ltd.

Tetrahydropalmatine protects against methamphetamine-induced spatial learning and memory impairment in mice

Institute of Scientific and Technical Information of China (English)

Yan-Jiong Chen; Teng Chen; Yan-Ling Liu; Qing Zhong; Yan-Fang Yu; Hong-Liang Su; Haroldo A.Toque; Yong-Hui Dang; Feng Chen; Ming Xu

2012-01-01

[Objective] The purpose of this study was to investigate the effect of methamphetamine (MA) on spatial learning and memory and the role of tetrahydropalmatine (THP) in MA-induced changes in these phenomena in mice.[Methods]Male C57BL/6 mice were randomly divided into eight groups,according to different doses of MA,different doses of THP,treatment with both MA and THP,and saline controls.Spatial learning and memory were assessed using the Morris water maze.Western blot was used to detect the expression of extracellular signal-regulated protein kinase (ERK) in the mouse prefrontal cortex (PFC) and hippocampus.[Results] Repeated MA treatment significantly increased the escape latency in the learning phase and decreased the number of platform site crossings in the memory-test phase.ERK1/2 expression was decreased in the PFC but not in the hippocampus of the MA-treated mice.Repeated THP treatment alone did not affect the escape latency,the number of platform site crossings or the total ERK1/2 expression in the brain.Statistically significantly shorter escape latencies and more platform site crossings occurred in MA+THP-trcatcd mice than in MA-treated mice.[Conclusion]Repeated MA administration impairs spatial learning and memory in mice,and its co-administration with THP prevents this impairment,which is probably attributable to changed ERK1/2 expression in the PFC.This study contributes to uncovering the mechanism underlying MA abuse,and to exploring potential therapies.

Visual impairment in FOXG1-mutated individuals and mice.

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Boggio, E M; Pancrazi, L; Gennaro, M; Lo Rizzo, C; Mari, F; Meloni, I; Ariani, F; Panighini, A; Novelli, E; Biagioni, M; Strettoi, E; Hayek, J; Rufa, A; Pizzorusso, T; Renieri, A; Costa, M

2016-06-02

The Forkead Box G1 (FOXG1 in humans, Foxg1 in mice) gene encodes for a DNA-binding transcription factor, essential for the development of the telencephalon in mammalian forebrain. Mutations in FOXG1 have been reported to be involved in the onset of Rett Syndrome, for which sequence alterations of MECP2 and CDKL5 are known. While visual alterations are not classical hallmarks of Rett syndrome, an increasing body of evidence shows visual impairment in patients and in MeCP2 and CDKL5 animal models. Herein we focused on the functional role of FOXG1 in the visual system of animal models (Foxg1(+/Cre) mice) and of a cohort of subjects carrying FOXG1 mutations or deletions. Visual physiology of Foxg1(+/Cre) mice was assessed by visually evoked potentials, which revealed a significant reduction in response amplitude and visual acuity with respect to wild-type littermates. Morphological investigation showed abnormalities in the organization of excitatory/inhibitory circuits in the visual cortex. No alterations were observed in retinal structure. By examining a cohort of FOXG1-mutated individuals with a panel of neuro-ophthalmological assessments, we found that all of them exhibited visual alterations compatible with high-level visual dysfunctions. In conclusion our data show that Foxg1 haploinsufficiency results in an impairment of mouse and human visual cortical function. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Impaired angiogenesis during fracture healing in GPCR kinase 2 interacting protein-1 (GIT1 knock out mice.

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Guoyong Yin

Full Text Available G protein coupled receptor kinase 2 (GRK2 interacting protein-1 (GIT1, is a scaffold protein that plays an important role in angiogenesis and osteoclast activity. We have previously demonstrated that GIT1 knockout (GIT1 KO mice have impaired angiogenesis and dysregulated osteoclast podosome formation leading to a reduction in the bone resorbing ability of these cells. Since both angiogenesis and osteoclast-mediated bone remodeling are involved in the fracture healing process, we hypothesized that GIT1 participates in the normal progression of repair following bone injury. In the present study, comparison of fracture healing in wild type (WT and GIT1 KO mice revealed altered healing in mice with loss of GIT1 function. Alcian blue staining of fracture callus indicated a persistence of cartilagenous matrix in day 21 callus samples from GIT1 KO mice which was temporally correlated with increased type 2 collagen immunostaining. GIT1 KO mice also showed a decrease in chondrocyte proliferation and apoptosis at days 7 and 14, as determined by PCNA and TUNEL staining. Vascular microcomputed tomography analysis of callus samples at days 7, 14 and 21 revealed decreased blood vessel volume, number, and connection density in GIT1 KO mice compared to WT controls. Correlating with this, VEGF-A, phospho-VEGFR2 and PECAM1 (CD31 were decreased in GIT1 KO mice, indicating reduced angiogenesis with loss of GIT1. Finally, calluses from GIT1 KO mice displayed a reduced number of tartrate resistant acid phosphatase-positive osteoclasts at days 14 and 21. Collectively, these results indicate that GIT1 is an important signaling participant in fracture healing, with gene ablation leading to reduced callus vascularity and reduced osteoclast number in the healing callus.

Behavioral phenotyping of Parkin-deficient mice: looking for early preclinical features of Parkinson's disease.

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Daniel Rial

Full Text Available There is considerable evidence showing that the neurodegenerative processes that lead to sporadic Parkinson's disease (PD begin many years before the appearance of the characteristic motor symptoms. Neuropsychiatric, sensorial and cognitive deficits are recognized as early non-motor manifestations of PD, and are not attenuated by the current anti-parkinsonian therapy. Although loss-of-function mutations in the parkin gene cause early-onset familial PD, Parkin-deficient mice do not display spontaneous degeneration of the nigrostriatal pathway or enhanced vulnerability to dopaminergic neurotoxins such as 6-OHDA and MPTP. Here, we employed adult homozygous C57BL/6 mice with parkin gene deletion on exon 3 (parkin-/- to further investigate the relevance of Parkin in the regulation of non-motor features, namely olfactory, emotional, cognitive and hippocampal synaptic plasticity. Parkin-/- mice displayed normal performance on behavioral tests evaluating olfaction (olfactory discrimination, anxiety (elevated plus-maze, depressive-like behavior (forced swimming and tail suspension and motor function (rotarod, grasping strength and pole. However, parkin-/- mice displayed a poor performance in the open field habituation, object location and modified Y-maze tasks suggestive of procedural and short-term spatial memory deficits. These behavioral impairments were accompanied by impaired hippocampal long-term potentiation (LTP. These findings indicate that the genetic deletion of parkin causes deficiencies in hippocampal synaptic plasticity, resulting in memory deficits with no major olfactory, emotional or motor impairments. Therefore, parkin-/- mice may represent a promising animal model to study the early stages of PD and for testing new therapeutic strategies to restore learning and memory and synaptic plasticity impairments in PD.

Zinc deficiency with reduced mastication impairs spatial memory in young adult mice.

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Kida, Kumiko; Tsuji, Tadataka; Tanaka, Susumu; Kogo, Mikihiko

2015-12-01

Sufficient oral microelements such as zinc and fully chewing of foods are required to maintain cognitive function despite aging. No knowledge exists about the combination of factors such as zinc deficiency and reduced mastication on learning and memory. Here we show that tooth extraction only in 8-week-old mice did not change the density of glial fibrillary acidic protein-labeled astrocytes in the hippocampus or spatial memory parameters. However, tooth extraction followed by zinc deprivation strongly impaired spatial memory and led to an increase in astrocytic density in the hippocampal CA1 region. The impaired spatial performance in the zinc-deficient only (ZD) mice also coincided well with the increase in the astrocytic density in the hippocampal CA1 region. After switching both zinc-deficient groups to a normal diet with sufficient zinc, spatial memory recovered, and more time was spent in the quadrant with the goal in the probe test in the mice with tooth extraction followed by zinc deprivation (EZD) compared to the ZD mice. Interestingly, we found no differences in astrocytic density in the CA1 region among all groups at 22 weeks of age. Furthermore, the escape latency in a visible probe test at all times was longer in zinc-deficient groups than the others and demonstrated a negative correlation with body weight. No significant differences in escape latency were observed in the visible probe test among the ZD, EZD, and normal-fed control at 4 weeks (CT4w) groups in which body weight was standardized to that of the EZD group, or in the daily reduction in latency between the normal-fed control and CT4w groups. Our data showed that zinc-deficient feeding during a young age impairs spatial memory performance and leads to an increase in astrocytic density in the hippocampal CA1 region and that zinc-sufficient feeding is followed by recovery of the impaired spatial memory along with changes in astrocytic density. The combination of the two factors, zinc deficiency

Impaired memory of eyeblink conditioning in CaMKIV KO mice.

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Lee, Ka Hung; Chatila, Talal A; Ram, Rana A; Thompson, Richard F

2009-04-01

The calcium/calmodulin-dependent protein kinase type IV (CaMKIV) is highly expressed in cerebellar cortical granule cells and deep nuclear neurons in the cerebellum. It mediates the phosphorylation and activation of the cAMP-dependent response element binding protein (CREB). In several paradigms CREB-dependent transcription is required for cellular events underlying long-term memory processes. Also, CaMKIV deficiency results in impaired long-term depression (LTD) induction in cerebellar cortex. To investigate the function of CaMKIV in the cerebellum, Wild-type (WT) and CaMKIV KO mice were tested with delay eyeblink conditioning. KO and WT mice did not differ in acquisition, but the KO mice showed a significantly lower conditioned response (CR) percentage than the WT mice in the retention testing and retraining period. The CR peak latencies for the two groups did not differ in acquisition but were shorter for the KO mice in the testing period. No significant differences were found between KO and WT mice in spontaneous eyeblink activity, auditory brainstem response (ABR) amplitudes, and tail-flick latency. The results suggest an important role for CaMKIV in long-term memory in the cerebellum. (c) 2009 APA, all rights reserved.

High Insulin Levels in KK-Ay Diabetic Mice Cause Increased Cortical Bone Mass and Impaired Trabecular Micro-Structure

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Cen Fu

2015-04-01

Full Text Available Type 2 diabetes mellitus (T2DM is a chronic disease characterized by hyperglycemia, hyperinsulinemia and complications, including obesity and osteoporosis. Rodents have been widely used to model human T2DM and investigate its effect on the skeleton. We aimed to investigate skeletal alterations in Yellow Kuo Kondo (KK-Ay diabetic mice displaying high insulin and glucose levels. Bone mineral density (BMD, micro-architecture and bone metabolism-related genes were analyzed. The total femoral areal BMD (aBMD, cortical volumetric BMD (vBMD and thickness were significantly increased in KK-Ay mice, while the trabecular vBMD and mineralized bone volume/tissue volume (BV/TV, trabecular thickness and number were decreased compared to C57BL mice. The expression of both osteoblast-related genes, such as osteocalcin (OC, bone sialoprotein, Type I Collagen, osteonectin, RUNX2 and OSX, and osteoclast-related genes, such as TRAP and TCIRG, were up-regulated in KK-Ay mice. Correlation analyses showed that serum insulin levels were positively associated with aBMD, cortical vBMD and thickness and negatively associated with trabecular vBMD and micro-architecture. In addition, serum insulin levels were positively related to osteoblast-related and osteoclast-related gene expression. Our data suggest that high insulin levels in KK-Ay diabetic mice may increase cortical bone mass and impair trabecular micro-structure by up-regulating osteoblast-and osteoclast-related gene expression.

Cognitive-Enhancing Effect of Dianthus superbus var. Longicalycinus on Scopolamine-Induced Memory Impairment in Mice.

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Weon, Jin Bae; Jung, Youn Sik; Ma, Choong Je

2016-05-01

Dianthus superbus (D. superbus) is a traditional crude drug used for the treatment of urethritis, carbuncles and carcinomas. The objective of this study was to confirm the cognitive enhancing effect of D. superbus in memory impairment induced mice and to elucidate the possible potential mechanism. Effect of D. superbus on scopolamine induced memory impairment on mice was evaluated using the Morris water maze and passive avoidance tests. We also investigated acetylcholinesterase (AChE) activity and brain-derived neurotropic factor (BDNF) expression in scopolamine-induced mice. HPLC-DAD analysis was performed to identify active compounds in D. superbus. The results revealed that D. superbus attenuated the learning and memory impairment induced by scopolamine. D. superbus also inhibited AChE levels in the hippocampi of the scopolamine-injected mice. Moreover, D. superbus increased BDNF expression in the hippocampus. Eight compounds were identified using HPLC-DAD analysis. The content of 4-hydroxyphenyl acetic acid was higher than contents of other compounds. These results indicated that D. superbus improved memory functioning accompanied by inhibition of AChE and upregulation of BDNF, suggesting that D. superbus may be a useful therapeutic agent for the prevention or treatment of Alzheimer's disease.

Intranasal siRNA administration reveals IGF2 deficiency contributes to impaired cognition in Fragile X syndrome mice.

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Pardo, Marta; Cheng, Yuyan; Velmeshev, Dmitry; Magistri, Marco; Eldar-Finkelman, Hagit; Martinez, Ana; Faghihi, Mohammad A; Jope, Richard S; Beurel, Eleonore

2017-03-23

Molecular mechanisms underlying learning and memory remain imprecisely understood, and restorative interventions are lacking. We report that intranasal administration of siRNAs can be used to identify targets important in cognitive processes and to improve genetically impaired learning and memory. In mice modeling the intellectual deficiency of Fragile X syndrome, intranasally administered siRNA targeting glycogen synthase kinase-3β (GSK3β), histone deacetylase-1 (HDAC1), HDAC2, or HDAC3 diminished cognitive impairments. In WT mice, intranasally administered brain-derived neurotrophic factor (BDNF) siRNA or HDAC4 siRNA impaired learning and memory, which was partially due to reduced insulin-like growth factor-2 (IGF2) levels because the BDNF siRNA- or HDAC4 siRNA-induced cognitive impairments were ameliorated by intranasal IGF2 administration. In Fmr1 -/- mice, hippocampal IGF2 was deficient, and learning and memory impairments were ameliorated by IGF2 intranasal administration. Therefore intranasal siRNA administration is an effective means to identify mechanisms regulating cognition and to modulate therapeutic targets.

Adenovirus Particles that Display the Plasmodium falciparum Circumsporozoite Protein NANP Repeat Induce Sporozoite-Neutralizing Antibodies in Mice

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Palma, Christopher; Overstreet, Michael G.; Guedon, Jean-Marc; Hoiczyk, Egbert; Ward, Cameron; Karen, Kasey A.; Zavala, Fidel; Ketner, Gary

2011-01-01

Adenovirus particles can be engineered to display exogenous peptides on their surfaces by modification of viral capsid proteins, and particles that display pathogen-derived peptides can induce protective immunity. We constructed viable recombinant adenoviruses that display B-cell epitopes from the Plasmodium falciparum circumsporozoite protein (PfCSP) in the major adenovirus capsid protein, hexon. Recombinants induced high-titer antibodies against CSP when injected intraperitoneally into mice. Serum obtained from immunized mice recognized both recombinant PfCSP protein and P. falciparum sporozoites, and neutralized P. falciparum sporozoites in vitro. Replicating adenovirus vaccines have provided economical protection against adenovirus disease for over three decades. The recombinants described here may provide a path to an affordable malaria vaccine in the developing world. PMID:21199707

Constitutive activation of Gli2 impairs bone formation in postnatal growing mice.

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Kyu Sang Joeng

Full Text Available Indian hedgehog (Ihh signaling is indispensable for osteoblast differentiation during endochondral bone development in the mouse embryo. We have previously shown that the Gli2 transcription activator critically mediates Ihh function in osteoblastogenesis. To explore the possibility that activation of Hedgehog (Hh signaling may enhance bone formation, we generated mice that expressed a constitutively active form of Gli2 in the Osx-lineage cells. Unexpectedly, these mice exhibited severe osteopenia due to a marked decrease in osteoblast number and function, although bone resorption was not affected. Quantitative analyses of the molecular markers indicated that osteoblast differentiation was impaired in the mutant mouse. However, the osteoblast-lineage cells isolated from these mice exhibited more robust osteoblast differentiation than normal in vitro. Similarly, pharmacological stimulation of Hh signaling enhanced osteoblast differentiation from Osx-expressing cells isolated from the wild-type mouse. Thus, even though Hh signaling directly promotes osteoblast differentiation in vitro, constitutive activation of this pathway impairs bone formation in vivo, perhaps through an indirect mechanism.

Dual specificity phosphatase 6 deficiency is associated with impaired systemic glucose tolerance and reversible weight retardation in mice.

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Katrin Pfuhlmann

Full Text Available Here, we aimed to investigate the potential role of DUSP6, a dual specificity phosphatase, that specifically inactivates extracellular signal-regulated kinase (ERK, for the regulation of body weight and glucose homeostasis. We further assessed whether metabolic challenges affect Dusp6 expression in selected brain areas or white adipose tissue. Hypothalamic Dusp6 mRNA levels remained unchanged in chow-fed lean vs. high fat diet (HFD fed obese C57Bl/6J mice, and in C57Bl/6J mice undergoing prolonged fasting or refeeding with fat free diet (FFD or HFD. Similarly, Dusp6 expression levels were unchanged in selected brain regions of Lepob mice treated with 1 mg/kg of leptin for 6 days, compared to pair-fed or saline-treated Lepob controls. Dusp6 expression levels remained unaltered in vitro in primary adipocytes undergoing differentiation, but were increased in eWAT of HFD-fed obese C57Bl/6J mice, compared to chow-fed lean controls. Global chow-fed DUSP6 KO mice displayed reduced body weight and lean mass and slightly increased fat mass at a young age, which is indicative for early-age weight retardation. Subsequent exposure to HFD led to a significant increase in lean mass and body weight in DUSP6 deficient mice, compared to WT controls. Nevertheless, after 26 weeks of high-fat diet exposure, we observed comparable body weight, fat and lean mass in DUSP6 WT and KO mice, suggesting overall normal susceptibility to develop obesity. In line with the increased weight gain to compensate for early-age weight retardation, HFD-fed DUSP6 KO displayed increased expression levels of anabolic genes involved in lipid and cholesterol metabolism in the epididymal white adipose tissue (eWAT, compared to WT controls. Glucose tolerance was perturbed in both chow-fed lean or HFD-fed obese DUSP6 KO, compared to their respective WT controls. Overall, our data indicate that DUSP6 deficiency has limited impact on the regulation of energy metabolism, but impairs systemic

Impaired mastication reduced newly generated neurons at the accessory olfactory bulb and pheromonal responses in mice.

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Utsugi, Chizuru; Miyazono, Sadaharu; Osada, Kazumi; Matsuda, Mitsuyoshi; Kashiwayanagi, Makoto

2014-12-01

A large number of neurons are generated at the subventricular zone (SVZ) even during adulthood. In a previous study, we have shown that a reduced mastication impairs both neurogenesis in the SVZ and olfactory functions. Pheromonal signals, which are received by the vomeronasal organ, provide information about reproductive and social states. Vomeronasal sensory neurons project to the accessory olfactory bulb (AOB) located on the dorso-caudal surface of the main olfactory bulb. Newly generated neurons at the SVZ migrate to the AOB and differentiate into granule cells and periglomerular cells. This study aimed to explore the effects of changes in mastication on newly generated neurons and pheromonal responses. Bromodeoxyuridine-immunoreactive (BrdU-ir; a marker of DNA synthesis) and Fos-ir (a marker of neurons excited) structures in sagittal sections of the AOB after exposure to urinary odours were compared between the mice fed soft and hard diets. The density of BrdU-ir cells in the AOB in the soft-diet-fed mice after 1 month was essentially similar to that of the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 3 or 6 months than in the hard-diet-fed mice. The density of Fos-ir cells in the soft-diet-fed mice after 2 months was essentially similar to that in the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 4 months than in the hard-diet-fed mice. The present results suggest that impaired mastication reduces newly generated neurons at the AOB, which in turn impairs olfactory function at the AOB. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ameliorating Effects of Ethanol Extract of Fructus mume on Scopolamine-Induced Memory Impairment in Mice

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Min-Soo Kim

2015-01-01

Full Text Available We previously reported that Fructus mume (F. mume extract shows protective effects on memory impairments and anti-inflammatory effects induced by chronic cerebral hypoperfusion. Neurodegeneration of basal cholinergic neurons is also observed in the brain with chronic cerebral hypoperfusion. Therefore, the present study was conducted to examine whether F. mume extracts enhance cognitive function via the action of cholinergic neuron using a scopolamine-induced animal model of memory impairments. F. mume (50, 100, or 200 mg/kg was administered to C57BL/6 mice for 14 days (days 1–14 and memory impairment was induced by scopolamine (1 mg/kg, a muscarinic receptor antagonist for 7 days (days 8–14. Spatial memory was assessed using Morris water maze and hippocampal level of acetylcholinesterase (AChE and choline acetyltransferase (ChAT was examined by ELISA and immunoblotting. Mice that received scopolamine alone showed impairments in acquisition and retention in Morris water maze task and increased activity of AChE in the hippocampus. Mice that received F. mume and scopolamine showed no scopolamine-induced memory impairment and increased activity of AChE. In addition, treatments of F. mume increased ChAT expression in the hippocampus. These results indicated that F. mume might enhance cognitive function via action of cholinergic neurons.

Role of insulin signaling impairment, adiponectin and dyslipidemia in peripheral and central neuropathy in mice

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Nicholas J. Anderson

2014-06-01

Full Text Available One of the tissues or organs affected by diabetes is the nervous system, predominantly the peripheral system (peripheral polyneuropathy and/or painful peripheral neuropathy but also the central system with impaired learning, memory and mental flexibility. The aim of this study was to test the hypothesis that the pre-diabetic or diabetic condition caused by a high-fat diet (HFD can damage both the peripheral and central nervous systems. Groups of C57BL6 and Swiss Webster mice were fed a diet containing 60% fat for 8 months and compared to control and streptozotocin (STZ-induced diabetic groups that were fed a standard diet containing 10% fat. Aspects of peripheral nerve function (conduction velocity, thermal sensitivity and central nervous system function (learning ability, memory were measured at assorted times during the study. Both strains of mice on HFD developed impaired glucose tolerance, indicative of insulin resistance, but only the C57BL6 mice showed statistically significant hyperglycemia. STZ-diabetic C57BL6 mice developed learning deficits in the Barnes maze after 8 weeks of diabetes, whereas neither C57BL6 nor Swiss Webster mice fed a HFD showed signs of defects at that time point. By 6 months on HFD, Swiss Webster mice developed learning and memory deficits in the Barnes maze test, whereas their peripheral nervous system remained normal. In contrast, C57BL6 mice fed the HFD developed peripheral nerve dysfunction, as indicated by nerve conduction slowing and thermal hyperalgesia, but showed normal learning and memory functions. Our data indicate that STZ-induced diabetes or a HFD can damage both peripheral and central nervous systems, but learning deficits develop more rapidly in insulin-deficient than in insulin-resistant conditions and only in Swiss Webster mice. In addition to insulin impairment, dyslipidemia or adiponectinemia might determine the neuropathy phenotype.

Working Memory Deficits, Increased Anxiety-Like Traits, and Seizure Susceptibility in BDNF Overexpressing Mice

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Papaleo, Francesco; Silverman, Jill L.; Aney, Jordan; Tian, Qingjun; Barkan, Charlotte L.; Chadman, Kathryn K.; Crawley, Jacqueline N.

2011-01-01

BDNF regulates components of cognitive processes and has been implicated in psychiatric disorders. Here we report that genetic overexpression of the BDNF mature isoform (BDNF-tg) in female mice impaired working memory functions while sparing components of fear conditioning. BDNF-tg mice also displayed reduced breeding efficiency, higher…

Amyloid β Is Not the Major Factor Accounting for Impaired Adult Hippocampal Neurogenesis in Mice Overexpressing Amyloid Precursor Protein

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Hongyu Pan

2016-10-01

Full Text Available Adult hippocampal neurogenesis was impaired in several Alzheimer's disease models overexpressing mutant human amyloid precursor protein (hAPP. However, the effects of wild-type hAPP on adult neurogenesis and whether the impaired adult hippocampal neurogenesis was caused by amyloid β (Aβ or APP remained unclear. Here, we found that neurogenesis was impaired in the dentate gyrus (DG of adult mice overexpressing wild-type hAPP (hAPP-I5 compared with controls. However, the adult hippocampal neurogenesis was more severely impaired in hAPP-I5 than that in hAPP-J20 mice, which express similar levels of hAPP mRNA but much higher levels of Aβ. Furthermore, reducing Aβ levels did not affect the number of doublecortin-positive cells in the DG of hAPP-J20 mice. Our results suggested that hAPP was more likely an important factor inhibiting adult neurogenesis, and Aβ was not the major factor affecting neurogenesis in the adult hippocampus of hAPP mice.

Ursodeoxycholic acid impairs atherogenesis and promotes plaque regression by cholesterol crystal dissolution in mice.

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Bode, Niklas; Grebe, Alena; Kerksiek, Anja; Lütjohann, Dieter; Werner, Nikos; Nickenig, Georg; Latz, Eicke; Zimmer, Sebastian

2016-09-09

Atherosclerosis is a chronic inflammatory disease driven primarily by a continuous retention of cholesterol within the subendothelial space where it precipitates to form cholesterol crystals (CC). These CC trigger a complex inflammatory response through activation of the NLRP3 inflammasome and promote lesion development. Here we examined whether increasing cholesterol solubility with ursodeoxycholic acid (UDCA) affects vascular CC formation and ultimately atherosclerotic lesion development. UDCA mediated intracellular CC dissolution in macrophages and reduced IL-1β production. In ApoE(-/-) mice, UDCA treatment not only impaired atherosclerotic plaque development but also mediated regression of established vascular lesions. Importantly, mice treated with UDCA had decreased CC-depositions in atherosclerotic plaques compared to controls. Together, our data demonstrate that UDCA impaired CC and NLRP3 dependent inflammation by increasing cholesterol solubility and diminished atherosclerosis in mice. Copyright © 2016 Elsevier Inc. All rights reserved.

Adenovirus Particles that Display the Plasmodium falciparum Circumsporozoite Protein NANP Repeat Induce Sporozoite-Neutralizing Antibodies in Mice

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Palma, Christopher; Overstreet, Michael G.; Guedon, Jean-Marc; Hoiczyk, Egbert; Ward, Cameron; Karen, Kasey A.; Zavala, Fidel; Ketner, Gary

2011-01-01

Adenovirus particles can be engineered to display exogenous peptides on their surfaces by modification of viral capsid proteins, and particles that display pathogen-derived peptides can induce protective immunity. We constructed viable recombinant adenoviruses that display B-cell epitopes from the Plasmodium falciparum circumsporozoite protein (PfCSP) in the major adenovirus capsid protein, hexon. Recombinants induced high-titer antibodies against CSP when injected intraperitoneally into mice...

Adult Gli2+/-;Gli3Δ699/+ Male and Female Mice Display a Spectrum of Genital Malformation.

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Fei He

Full Text Available Disorders of sexual development (DSD encompass a broad spectrum of urogenital malformations and are amongst the most common congenital birth defects. Although key genetic factors such as the hedgehog (Hh family have been identified, a unifying postnatally viable model displaying the spectrum of male and female urogenital malformations has not yet been reported. Since human cases are diagnosed and treated at various stages postnatally, equivalent mouse models enabling analysis at similar stages are of significant interest. Additionally, all non-Hh based genetic models investigating DSD display normal females, leaving female urogenital development largely unknown. Here, we generated compound mutant mice, Gli2+/-;Gli3Δ699/+, which exhibit a spectrum of urogenital malformations in both males and females upon birth, and also carried them well into adulthood. Analysis of embryonic day (E18.5 and adult mice revealed shortened anogenital distance (AGD, open ventral urethral groove, incomplete fusion of scrotal sac, abnormal penile size and structure, and incomplete testicular descent with hypoplasia in male mice, whereas female mutant mice displayed reduced AGD, urinary incontinence, and a number of uterine anomalies such as vaginal duplication. Male and female fertility was also investigated via breeding cages, and it was identified that male mice were infertile while females were unable to deliver despite becoming impregnated. We propose that Gli2+/-;Gli3Δ699/+ mice can serve as a genetic mouse model for common DSD such as cryptorchidism, hypospadias, and incomplete fusion of the scrotal sac in males, and a spectrum of uterine and vaginal abnormalities along with urinary incontinence in females, which could prove essential in revealing new insights into their equivalent diseases in humans.

Muscle wasting and impaired myogenesis in tumor bearing mice are prevented by ERK inhibition.

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Fabio Penna

Full Text Available BACKGROUND: The onset of cachexia is a frequent feature in cancer patients. Prominent characteristic of this syndrome is the loss of body and muscle weight, this latter being mainly supported by increased protein breakdown rates. While the signaling pathways dependent on IGF-1 or myostatin were causally involved in muscle atrophy, the role of the Mitogen-Activated-Protein-Kinases is still largely debated. The present study investigated this point on mice bearing the C26 colon adenocarcinoma. METHODOLOGY/PRINCIPAL FINDINGS: C26-bearing mice display a marked loss of body weight and muscle mass, this latter associated with increased phosphorylated (p-ERK. Administration of the ERK inhibitor PD98059 to tumor bearers attenuates muscle depletion and weakness, while restoring normal atrogin-1 expression. In C26 hosts, muscle wasting is also associated with increased Pax7 expression and reduced myogenin levels. Such pattern, suggestive of impaired myogenesis, is reversed by PD98059. Increased p-ERK and reduced myosin heavy chain content can be observed in TNFα-treated C2C12 myotubes, while decreased myogenin and MyoD levels occur in differentiating myoblasts exposed to the cytokine. All these changes are prevented by PD98059. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that ERK is involved in the pathogenesis of muscle wasting in cancer cachexia and could thus be proposed as a therapeutic target.

Elevation of endogenous anandamide impairs LTP, learning, and memory through CB1 receptor signaling in mice.

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Basavarajappa, Balapal S; Nagre, Nagaraja N; Xie, Shan; Subbanna, Shivakumar

2014-07-01

In rodents, many exogenous and endogenous cannabinoids, such as anandamide (AEA) and 2-arachidonyl glycerol (2-AG), have been shown to play an important role in certain hippocampal memory processes. However, the mechanisms by which endogenous AEA regulate this processes are not well understood. Here the effects of AEA on long-term potentiation (LTP), hippocampal-dependent learning and memory tasks, pERK1/2, pCaMKIV, and pCREB signaling events in both cannabinoid receptor type 1 (CB1R) wild-type (WT) and knockout (KO) mice were assessed following administration of URB597, an inhibitor of the fatty acid amide hydrolase (FAAH). Acute administration of URB597 enhanced AEA levels without affecting the levels of 2-AG or CB1R in the hippocampus and neocortex as compared to vehicle. In hippocampal slices, URB597 impaired LTP in CB1R WT but not in KO littermates. URB597 impaired object recognition, spontaneous alternation and spatial memory in the Y-maze test in CB1R WT mice but not in KO mice. Furthermore, URB597 enhanced ERK phosphorylation in WT without affecting total ERK levels in WT or KO mice. URB597 impaired CaMKIV and CREB phosphorylation in WT but not in KO mice. CB1R KO mice have a lower pCaMKIV/CaMKIV ratio and higher pCREB/CREB ratio as compared to WT littermates. Our results indicate that pharmacologically elevated AEA impair LTP, learning and memory and inhibit CaMKIV and CREB phosphorylation, via the activation of CB1Rs. Collectively, these findings also suggest that pharmacological elevation of AEA beyond normal concentrations is also detrimental for the underlying physiological responses. © 2014 Wiley Periodicals, Inc.

Prevention of vision loss protects against age-related impairment in learning and memory performance in DBA/2J mice

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Aimee eWong

2013-09-01

Full Text Available The DBA/2J mouse is a model of pigmentary glaucoma in humans as it shows age‐related increases in intraocular pressure, retinal ganglion cell death and visual impairment. Previously, we showed that visual ability declines from 9 ‐12 months of age and visual impairment is correlated with poor learning and memory performance in visuo‐spatial tasks but not in tasks that do not depend on visual cues. To test the sensory impairment hypothesis of aging, which postulates that sensory impaired individuals are disadvantaged in their performance on psychometric tests as a direct result of difficulties in sensory perception, we treated DBA/2J mice with a conventional glaucoma medication used in humans (Timoptic‐XE, 0.00, 0.25 or 0.50% daily from 9 weeks to 12 months of age to determine whether prevention of vision loss prevented the decline in visuo-spatial learning and memory performance. At all ages tested (3, 6, 9 and 12 months of age, mice treated with Timoptic-XE (0.25 and 0.50% maintained a high level of performance, while 12 month old control mice (0.00% exhibited impaired performance in visually‐dependent, but not non‐visual tasks. These results demonstrate that when sensory function is preserved, cognitive performance is normalized. Thus, as in many aging humans, DBA/2J mice show age-related decrements in performance on visually presented cognitive tests, not because of cognitive impairment but as a direct consequence of poor visual ability. Our results demonstrate that age-related impairment in performance in visuo-spatial tasks in DBA/2J mice can be prevented by the preservation of visual ability.

Prevention of vision loss protects against age-related impairment in learning and memory performance in DBA/2J mice.

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Wong, Aimée A; Brown, Richard E

2013-01-01

The DBA/2J mouse is a model of pigmentary glaucoma in humans as it shows age-related increases in intraocular pressure (IOP), retinal ganglion cell death and visual impairment. Previously, we showed that visual ability declines from 9 to 12 months of age and visual impairment is correlated with poor learning and memory performance in visuo-spatial tasks but not in tasks that do not depend on visual cues. To test the "sensory impairment" hypothesis of aging, which postulates that sensory impaired individuals are disadvantaged in their performance on psychometric tests as a direct result of difficulties in sensory perception, we treated DBA/2J mice with a conventional glaucoma medication used in humans (Timoptic-XE, 0.00, 0.25, or 0.50%) daily from 9 weeks to 12 months of age to determine whether prevention of vision loss prevented the decline in visuo-spatial learning and memory performance. At all ages tested (3, 6, 9, and 12 months of age), mice treated with Timoptic-XE (0.25 and 0.50%) maintained a high level of performance, while 12 month old control mice (0.00%) exhibited impaired performance in visually-dependent, but not non-visual tasks. These results demonstrate that when sensory function is preserved, cognitive performance is normalized. Thus, as in many aging humans, DBA/2J mice show age-related decrements in performance on visually presented cognitive tests, not because of cognitive impairment but as a direct consequence of poor visual ability. Our results demonstrate that age-related impairment in performance in visuo-spatial tasks in DBA/2J mice can be prevented by the preservation of visual ability.

In Vivo Measurements in Mice in the Bion-M 1 Mission

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Andreev-Andrievskiy, Alexander; Custaud, Marc-Antoine; Popova, Anfisa; Borovik, Anatoliy; Dolgov, Oleg; Anokhin, Konstantin; Tsvirkun, Daria; Vinogradova, Olga

The main aim of BION-M 1 mission was to reveal morphological, biochemical and molecular mechanisms of adaptation to prolonged exposure in microgravity. Besides that functional state and behavior were assessed in vivo using test battery, home cage observations and implantable telemetry in space-flown mice (SF), control mice from the ground replica of the flight experiment (GC) and in mice kept in vivarium (SFV and GCV). Blood pressure and heart rate were monitored continuously in a subgroup of mice using implantable telemetry throughout the flight as well as before and after it. After 30-days flight aboard BION-M 1 biosatellite SF mice have gained more weight than GC, SFV or GCV mice (11%). SF mice displayed pronounced motor impairment upon examination shortly after landing. 1 day after the flight mice were less active and more anxious in the open-field test, less coordinated in the Rotarod and aerial drop test and had less grip force compared to both control and pre-flight values. Exercise performance was greatly reduced after 30-days flight and recovered by day 7 post-flight. Before the flight mice were trained to perform a simple task using positively reinforced free operant conditioning approach. After the flight performance in the same task was preserved, however learning ability was impaired. Mice displayed drastic reduction of heart rate during launch and reentry acceleration periods. Heart rate (by 8-10%) and, to a lesser extent blood pressure (by 5%) were elevated during the 30-days flight. After return heart rate in SF mice remained elevated throughout the 7-days observation period with no apparent recovery. In summary, mice display pronounced disadaptation to 1g after 30-days exposure in microgravity with different physiological systems having different recovery dynamics. Of particular interest, hemodynamic reactions in mice closely resemble reactions in larger organisms, implying that factors that govern the cardiovascular system adaptation to

Pridopidine Reverses Phencyclidine-Induced Memory Impairment.

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Sahlholm, Kristoffer; Valle-León, Marta; Fernández-Dueñas, Víctor; Ciruela, Francisco

2018-01-01

Pridopidine is in clinical trials for Huntington's disease treatment. Originally developed as a dopamine D 2 receptor (D 2 R) ligand, pridopidine displays about 100-fold higher affinity for the sigma-1 receptor (sigma-1R). Interestingly, pridopidine slows disease progression and improves motor function in Huntington's disease model mice and, in preliminarily reports, Huntington's disease patients. The present study examined the anti-amnesic potential of pridopidine. Thus, memory impairment was produced in mice by administration of phencyclidine (PCP, 10 mg/kg/day) for 10 days, followed by 14 days' treatment with pridopidine (6 mg/kg/day), or saline. Finally, novel object recognition performance was assessed in the animals. Mice receiving PCP and saline exhibited deficits in novel object recognition, as expected, while pridopidine treatment counteracted PCP-induced memory impairment. The effect of pridopidine was attenuated by co-administration of the sigma receptor antagonist, NE-100 (10 mg/kg). Our results suggest that pridopidine exerts anti-amnesic and potentially neuroprotective actions. These data provide new insights into the therapeutic potential of pridopidine as a pro-cognitive drug.

Macrophage dysfunction impairs resolution of inflammation in the wounds of diabetic mice.

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Savita Khanna

2010-03-01

Full Text Available Chronic inflammation is a characteristic feature of diabetic cutaneous wounds. We sought to delineate novel mechanisms involved in the impairment of resolution of inflammation in diabetic cutaneous wounds. At the wound-site, efficient dead cell clearance (efferocytosis is a pre-requisite for the timely resolution of inflammation and successful healing.Macrophages isolated from wounds of diabetic mice showed significant impairment in efferocytosis. Impaired efferocytosis was associated with significantly higher burden of apoptotic cells in wound tissue as well as higher expression of pro-inflammatory and lower expression of anti-inflammatory cytokines. Observations related to apoptotic cell load at the wound site in mice were validated in the wound tissue of diabetic and non-diabetic patients. Forced Fas ligand driven elevation of apoptotic cell burden at the wound site augmented pro-inflammatory and attenuated anti-inflammatory cytokine response. Furthermore, successful efferocytosis switched wound macrophages from pro-inflammatory to an anti-inflammatory mode.Taken together, this study presents first evidence demonstrating that diabetic wounds suffer from dysfunctional macrophage efferocytosis resulting in increased apoptotic cell burden at the wound site. This burden, in turn, prolongs the inflammatory phase and complicates wound healing.

Impaired macrophage and satellite cell infiltration occurs in a muscle-specific fashion following injury in diabetic skeletal muscle.

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Matthew P Krause

Full Text Available Systemic elevations in PAI-1 suppress the fibrinolytic pathway leading to poor collagen remodelling and delayed regeneration of tibialis anterior (TA muscles in type-1 diabetic Akita mice. However, how impaired collagen remodelling was specifically attenuating regeneration in Akita mice remained unknown. Furthermore, given intrinsic differences between muscle groups, it was unclear if the reparative responses between muscle groups were different.Here we reveal that diabetic Akita muscles display differential regenerative responses with the TA and gastrocnemius muscles exhibiting reduced regenerating myofiber area compared to wild-type mice, while soleus muscles displayed no difference between animal groups following injury. Collagen levels in TA and gastrocnemius, but not soleus, were significantly increased post-injury versus controls. At 5 days post-injury, when degenerating/necrotic regions were present in both animal groups, Akita TA and gastrocnemius muscles displayed reduced macrophage and satellite cell infiltration and poor myofiber formation. By 10 days post-injury, necrotic regions were absent in wild-type TA but persisted in Akita TA. In contrast, Akita soleus exhibited no impairment in any of these measures compared to wild-type soleus. In an effort to define how impaired collagen turnover was attenuating regeneration in Akita TA, a PAI-1 inhibitor (PAI-039 was orally administered to Akita mice following cardiotoxin injury. PAI-039 administration promoted macrophage and satellite cell infiltration into necrotic areas of the TA and gastrocnemius. Importantly, soleus muscles exhibit the highest inducible expression of MMP-9 following injury, providing a mechanism for normative collagen degradation and injury recovery in this muscle despite systemically elevated PAI-1.Our findings suggest the mechanism underlying how impaired collagen remodelling in type-1 diabetes results in delayed regeneration is an impairment in macrophage

Transgenic mice display hair loss and regrowth overexpressing mutant Hr gene.

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Zhu, Kuicheng; Xu, Cunshuan; Zhang, Jintao; Chen, Yingying; Liu, Mengduan

2017-10-30

Mutations in the hairless (Hr) gene in both mice and humans have been implicated in the development of congenital atrichia, but the role of Hr in skin and hair follicle (HF) biology remains unknown. Here, we established transgenic mice (TG) overexpressing mutant Hr to investigate its specific role in the development of HF. Three transgenic lines were successfully constructed, and two of them (TG3 and TG8) displayed a pattern of hair loss and regrowth with alternation in the expression of HR protein. The mutant Hr gene inhibited the expression of the endogenous gene in transgenic individuals, which led to the development of alopecia. Interestingly, the hair regrew with the increase in the endogenous expression levels resulting from decreased mutant Hr expression. The findings of our study indicate that the changes in the expression of Hr result in hair loss or regrowth.

Role of insulin signaling impairment, adiponectin and dyslipidemia in peripheral and central neuropathy in mice.

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Anderson, Nicholas J; King, Matthew R; Delbruck, Lina; Jolivalt, Corinne G

2014-06-01

One of the tissues or organs affected by diabetes is the nervous system, predominantly the peripheral system (peripheral polyneuropathy and/or painful peripheral neuropathy) but also the central system with impaired learning, memory and mental flexibility. The aim of this study was to test the hypothesis that the pre-diabetic or diabetic condition caused by a high-fat diet (HFD) can damage both the peripheral and central nervous systems. Groups of C57BL6 and Swiss Webster mice were fed a diet containing 60% fat for 8 months and compared to control and streptozotocin (STZ)-induced diabetic groups that were fed a standard diet containing 10% fat. Aspects of peripheral nerve function (conduction velocity, thermal sensitivity) and central nervous system function (learning ability, memory) were measured at assorted times during the study. Both strains of mice on HFD developed impaired glucose tolerance, indicative of insulin resistance, but only the C57BL6 mice showed statistically significant hyperglycemia. STZ-diabetic C57BL6 mice developed learning deficits in the Barnes maze after 8 weeks of diabetes, whereas neither C57BL6 nor Swiss Webster mice fed a HFD showed signs of defects at that time point. By 6 months on HFD, Swiss Webster mice developed learning and memory deficits in the Barnes maze test, whereas their peripheral nervous system remained normal. In contrast, C57BL6 mice fed the HFD developed peripheral nerve dysfunction, as indicated by nerve conduction slowing and thermal hyperalgesia, but showed normal learning and memory functions. Our data indicate that STZ-induced diabetes or a HFD can damage both peripheral and central nervous systems, but learning deficits develop more rapidly in insulin-deficient than in insulin-resistant conditions and only in Swiss Webster mice. In addition to insulin impairment, dyslipidemia or adiponectinemia might determine the neuropathy phenotype. © 2014. Published by The Company of Biologists Ltd.

Aqueous extracts from asparagus stems prevent memory impairments in scopolamine-treated mice.

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Sui, Zifang; Qi, Ce; Huang, Yunxiang; Ma, Shufeng; Wang, Xinguo; Le, Guowei; Sun, Jin

2017-04-19

Aqueous extracts from Asparagus officinalis L. stems (AEAS) are rich in polysaccharides, gamma-amino butyric acid (GABA), and steroidal saponin. This study was designed to investigate the effects of AEAS on learning, memory, and acetylcholinesterase-related activity in a scopolamine-induced model of amnesia. Sixty ICR mice were randomly divided into 6 groups (n = 10) including the control group (CT), scopolamine group (SC), donepezil group (DON), low, medium, and high dose groups of AEAS (LS, MS, HS; 1.6 mL kg -1 , 8 mL kg -1 , 16 mL kg -1 ). The results showed that 8 mL kg -1 of AEAS used in this study significantly reversed scopolamine-induced cognitive impairments in mice in the novel object recognition test (P < 0.05) and the Y-maze test (P < 0.05), and also improved the latency to escape in the Morris water maze test (P < 0.05). Moreover, it significantly increased acetylcholine and inhibited acetylcholinesterase activity in the hippocampus, which was directly related to the reduction in learning and memory impairments. It also reversed scopolamine-induced reduction in the hippocampal brain-derived neurotrophic factor (BDNF) and the cAMP response element-binding protein (CREB) mRNA expression. AEAS protected against scopolamine-induced memory deficits. In conclusion, AEAS protected learning and memory function in mice by enhancing the activity of the cholinergic nervous system, and increasing BDNF and CREB expression. This suggests that AEAS has the potential to prevent cognitive impairments in age-related diseases, such as Alzheimer's disease.

Sildenafil citrate (Viagra) impairs fertilization and early embryo development in mice.

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Glenn, David R J; McClure, Neil; Cosby, S Louise; Stevenson, Michael; Lewis, Sheena E M

2009-03-01

To determine the effects of sildenafil citrate, a cyclic monophosphate-specific type 5 phosphodiesterase inhibitor known to affect sperm function, on fertilization and early embryo cleavage. This acute mammal study included male and female mice assigned randomly, the females sacrificed after mating and their oocytes/embryos evaluated at four time periods after treatment. Academic research environment. Male and female CBAB(6) mice. Female mice were injected intraperitoneally with 5 IU gonadotropin (hCG) to stimulate follicular growth and induce ovulation. They were each caged with a male that had been gavaged with sildenafil citrate (0.06 mg/0.05 mL) and allowed to mate. After 12, 36, 60, and 84 h, females were killed, their oviducts were dissected out, and retrieved embryos were assessed for blastomere number and quality. Fertilization rates and numbers of embryos were evaluated after treatment. Fertilization rates (day 1) were markedly reduced (-33%) in matings where the male had taken sildenafil citrate. Over days 2-4, the numbers of embryos developing in the treated group were significantly fewer than in the control group. There was also a trend for impaired cleavage rates within those embryos, although this did not reach significance. The impairments to fertility caused by sildenafil citrate have important implications for infertility centers and for couples who are using this drug precoitally while attempting to conceive.

Excessive Sensory Stimulation during Development Alters Neural Plasticity and Vulnerability to Cocaine in Mice.

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Ravinder, Shilpa; Donckels, Elizabeth A; Ramirez, Julian S B; Christakis, Dimitri A; Ramirez, Jan-Marino; Ferguson, Susan M

2016-01-01

Early life experiences affect the formation of neuronal networks, which can have a profound impact on brain function and behavior later in life. Previous work has shown that mice exposed to excessive sensory stimulation during development are hyperactive and novelty seeking, and display impaired cognition compared with controls. In this study, we addressed the issue of whether excessive sensory stimulation during development could alter behaviors related to addiction and underlying circuitry in CD-1 mice. We found that the reinforcing properties of cocaine were significantly enhanced in mice exposed to excessive sensory stimulation. Moreover, although these mice displayed hyperactivity that became more pronounced over time, they showed impaired persistence of cocaine-induced locomotor sensitization. These behavioral effects were associated with alterations in glutamatergic transmission in the nucleus accumbens and amygdala. Together, these findings suggest that excessive sensory stimulation in early life significantly alters drug reward and the neural circuits that regulate addiction and attention deficit hyperactivity. These observations highlight the consequences of early life experiences and may have important implications for children growing up in today's complex technological environment.

MicroRNA-Mediated Rescue of Fear Extinction Memory by miR-144-3p in Extinction-Impaired Mice.

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Murphy, Conor P; Li, Xiang; Maurer, Verena; Oberhauser, Michael; Gstir, Ronald; Wearick-Silva, Luis Eduardo; Viola, Thiago Wendt; Schafferer, Simon; Grassi-Oliveira, Rodrigo; Whittle, Nigel; Hüttenhofer, Alexander; Bredy, Timothy W; Singewald, Nicolas

2017-06-15

MicroRNA (miRNA)-mediated control of gene expression suggests that miRNAs are interesting targets and/or biomarkers in the treatment of anxiety- and trauma-related disorders, where often memory-associated gene expression is adversely affected. The role of miRNAs in the rescue of impaired fear extinction was assessed using the 129S1/SvlmJ (S1) mouse model of impaired fear extinction. miRNA microarray analysis, reverse transcription polymerase chain reaction, fluorescent in situ hybridization, lentiviral overexpression, and Luciferase reporter assays were used to gain insight into the mechanisms underlying miRNA-mediated normalization of deficient fear extinction. Rescuing impaired fear extinction via dietary zinc restriction was associated with differential expression of miRNAs in the amygdala. One candidate, miR-144-3p, robustly expressed in the basolateral amygdala, showed specific extinction-induced, but not fear-induced, increased expression in both extinction-rescued S1 mice and extinction-intact C57BL/6 (BL6) mice. miR-144-3p upregulation and effects on subsequent behavioral adaption was assessed in S1 and BL6 mice. miR-144-3p overexpression in the basolateral amygdala rescued impaired fear extinction in S1 mice, led to enhanced fear extinction acquisition in BL6 mice, and furthermore protected against fear renewal in BL6 mice. miR-144-3p targets a number of genes implicated in the control of plasticity-associated signaling cascades, including Pten, Spred1, and Notch1. In functional interaction studies, we revealed that the miR-144-3p target, PTEN, colocalized with miR-144-3p in the basolateral amygdala and showed functional downregulation following successful fear extinction in S1 mice. These findings identify a fundamental role of miR-144-3p in the rescue of impaired fear extinction and suggest this miRNA as a viable target in developing novel treatments for posttraumatic stress disorder and related disorders. Copyright © 2017 Society of Biological

Natural amyloid-β oligomers acutely impair the formation of a contextual fear memory in mice.

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Kittelberger, Kara A; Piazza, Fabrizio; Tesco, Giuseppina; Reijmers, Leon G

2012-01-01

Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD). It has been proposed that soluble amyloid-beta (Abeta) oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss.

Natural Amyloid-Beta Oligomers Acutely Impair the Formation of a Contextual Fear Memory in Mice

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Kittelberger, Kara A.; Piazza, Fabrizio; Tesco, Giuseppina; Reijmers, Leon G.

2012-01-01

Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD). It has been proposed that soluble amyloid-beta (Abeta) oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss. PMID:22238679

Transgenic mice expressing constitutive active MAPKAPK5 display gender-dependent differences in exploration and activity

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Moens Ugo

2007-11-01

Full Text Available Abstract Background The mitogen-activated protein kinases, MAPKs for short, constitute cascades of signalling pathways involved in the regulation of several cellular processes that include cell proliferation, differentiation and motility. They also intervene in neurological processes like fear conditioning and memory. Since little remains known about the MAPK-Activated Protein Kinase, MAPKAPK5, we constructed the first MAPKAPK knockin mouse model, using a constitutive active variant of MAPKAPK5 and analyzed the resulting mice for changes in anxiety-related behaviour. Methods We performed primary SHIRPA observations during background breeding into the C57BL/6 background and assessed the behaviour of the background-bred animals on the elevated plus maze and in the light-dark test. Our results were analyzed using Chi-square tests and homo- and heteroscedatic T-tests. Results Female transgenic mice displayed increased amounts of head dips and open arm time on the maze, compared to littermate controls. In addition, they also explored further into the open arm on the elevated plus maze and were less active in the closed arm compared to littermate controls. Male transgenic mice displayed no differences in anxiety, but their locomotor activity increased compared to non-transgenic littermates. Conclusion Our results revealed anxiety-related traits and locomotor differences between transgenic mice expressing constitutive active MAPKAPK5 and control littermates.

Conditional expression of constitutively active estrogen receptor α in chondrocytes impairs longitudinal bone growth in mice

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Ikeda, Kazuhiro; Tsukui, Tohru; Imazawa, Yukiko; Horie-Inoue, Kuniko; Inoue, Satoshi

2012-01-01

Highlights: ► Conditional transgenic mice expressing constitutively active estrogen receptor α (caERα) in chondrocytes were developed. ► Expression of caERα in chondrocytes impaired longitudinal bone growth in mice. ► caERα affects chondrocyte proliferation and differentiation. ► This mouse model is useful for understanding the physiological role of ERαin vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caERα ColII , expressing constitutively active mutant estrogen receptor (ER) α in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caERα ColII mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caERα ColII mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caERα ColII mice. These results suggest that ERα is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.

Vitamin D deficiency in mice impairs colonic antibacterial activity and predisposes to colitis.

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Lagishetty, Venu; Misharin, Alexander V; Liu, Nancy Q; Lisse, Thomas S; Chun, Rene F; Ouyang, Yi; McLachlan, Sandra M; Adams, John S; Hewison, Martin

2010-06-01

Vitamin D insufficiency is a global health issue. Although classically associated with rickets, low vitamin D levels have also been linked to aberrant immune function and associated health problems such as inflammatory bowel disease (IBD). To test the hypothesis that impaired vitamin D status predisposes to IBD, 8-wk-old C57BL/6 mice were raised from weaning on vitamin D-deficient or vitamin D-sufficient diets and then treated with dextran sodium sulphate (DSS) to induce colitis. Vitamin D-deficient mice showed decreased serum levels of precursor 25-hydroxyvitamin D(3) (2.5 +/- 0.1 vs. 24.4 +/- 1.8 ng/ml) and active 1,25-dihydroxyvitamin D(3) (28.8 +/- 3.1 vs. 45.6 +/- 4.2 pg/ml), greater DSS-induced weight loss (9 vs. 5%), increased colitis (4.71 +/- 0.85 vs. 1.57 +/- 0.18), and splenomegaly relative to mice on vitamin D-sufficient chow. DNA array analysis of colon tissue (n = 4 mice) identified 27 genes consistently (P < 0.05) up-regulated or down-regulated more than 2-fold in vitamin D-deficient vs. vitamin D-sufficient mice, in the absence of DSS-induced colitis. This included angiogenin-4, an antimicrobial protein involved in host containment of enteric bacteria. Immunohistochemistry confirmed that colonic angiogenin-4 protein was significantly decreased in vitamin D-deficient mice even in the absence of colitis. Moreover, the same animals showed elevated levels (50-fold) of bacteria in colonic tissue. These data show for the first time that simple vitamin D deficiency predisposes mice to colitis via dysregulated colonic antimicrobial activity and impaired homeostasis of enteric bacteria. This may be a pivotal mechanism linking vitamin D status with IBD in humans.

Enzyme-treated Asparagus officinalis extract shows neuroprotective effects and attenuates cognitive impairment in senescence-accelerated mice.

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Sakurai, Takuya; Ito, Tomohiro; Wakame, Koji; Kitadate, Kentaro; Arai, Takashi; Ogasawara, Junetsu; Kizaki, Takako; Sato, Shogo; Ishibashi, Yoshinaga; Fujiwara, Tomonori; Akagawa, Kimio; Ishida, Hitoshi; Ohno, Hideki

2014-01-01

Increases in the number of patients with dementia involving Alzheimer's disease (AD) are seen as a grave public health problem. In neurodegenerative disorders involving AD, biological stresses, such as oxidative and inflammatory stress, induce neural cell damage. Asparagus (Asparagus officinalis) is a popular vegetable, and an extract prepared from this reportedly possesses various beneficial biological activities. In the present study, we investigated the effects of enzyme-treated asparagus extract (ETAS) on neuronal cells and early cognitive impairment of senescence-accelerated mouse prone 8 (SAMP8) mice. The expression of mRNAs for factors that exert cytoprotective and anti-apoptotic functions, such as heat-shock protein 70 and heme oxygenase-1, was upregulated in NG108-15 neuronal cells by treatment with ETAS. Moreover, when release of lactate dehydrogenase from damaged NG108-15 cells was increased for cells cultured in medium containing either the nitric oxide donor sodium nitroprusside or the hypoxia mimic reagent cobalt chloride, ETAS significantly attenuated this cell damage. Also, when contextual fear memory, which is considered to be a hippocampus-dependent memory, was significantly impaired in SAMP8 mice, ETAS attenuated the cognitive impairment. These results suggest that ETAS produces cytoprotective effects in neuronal cells and attenuates the effects on the cognitive impairment of SAMP8 mice.

Oxidative stress with tau hyperphosphorylation in memory impaired 1,2-diacetylbenzene-treated mice.

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Kang, Sin-Woo; Kim, Sung Jin; Kim, Min-Sun

2017-09-05

Long-term exposure to organic solvent may be related to the incidence of neuronal diseases, such as, Alzheimer's disease, depression, multiple sclerosis, dementia, Parkinson's disease. Previously, the authors reported 1,2-diacetylbenzene (DAB; a neurotoxic metabolite of 1,2-diethylbenzene) causes central and peripheral neuropathies that lead to motor neuronal deficits. Furthermore, it is known DAB increases oxidative stress and protein adduct levels and impairs hippocampal neurogenesis in mice. The authors examined the relevance of oxidative stress and tau hyperphosphorylation in the hippocampus. Five-week-old male C57BL/6 mice were treated with 1 or 5mg/kg/day DAB for 2weeks. Neither overall body weight increases nor behavioral differences were observed after treatment, but kidney and liver weights decreased. Increased ROS production, activated glycogen synthase kinase-3β (GSK-3β) and tau hyperphosphorylation were observed in hippocampal homogenates. To assess memory impairment, the Morris Water Maze was used. Animals in the DAB-treated groups took longer to reach the platform. Movement patterns of DAB treated mice were more complicated and their swimming speeds were lower than those of controls. When SHSY5Y neuroblastoma cells were pretreated with NAC (an antioxidant) or a GSK-3β inhibitor, the expression of active GSK-3β and tau hyperphosphorylation were reduced. These results suggest ROS produced by DAB causes tau hyperphosphorylation via GSK-3β phosphorylation and it might be related to impaired memory deficit. Copyright © 2017 Elsevier B.V. All rights reserved.

Impaired Albumin Uptake and Processing Promote Albuminuria in OVE26 Diabetic Mice

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Long, Y. S.; Zheng, S.; Kralik, P. M.; Benz, F. W.

2016-01-01

The importance of proximal tubules dysfunction to diabetic albuminuria is uncertain. OVE26 mice have the most severe albuminuria of all diabetic mouse models but it is not known if impaired tubule uptake and processing are contributing factors. In the current study fluorescent albumin was used to follow the fate of albumin in OVE26 and normal mice. Compared to normal urine, OVE26 urine contained at least 23 times more intact fluorescent albumin but only 3-fold more 70 kD fluorescent dextran. This indicated that a function other than size selective glomerular sieving contributed to OVE26 albuminuria. Imaging of albumin was similar in normal and diabetic tubules for 3 hrs after injection. However 3 days after injection a subset of OVE26 tubules retained strong albumin fluorescence, which was never observed in normal mice. OVE26 tubules with prolonged retention of injected albumin lost the capacity to take up albumin and there was a significant correlation between tubules unable to eliminate fluorescent albumin and total albuminuria. TUNEL staining revealed a 76-fold increase in cell death in OVE26 tubules that retained fluorescent albumin. These results indicate that failure to process and dispose of internalized albumin leads to impaired albumin uptake, increased albuminuria, and tubule cell apoptosis. PMID:27822483

Flos Puerariae Extract Ameliorates Cognitive Impairment in Streptozotocin-Induced Diabetic Mice

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Zhong-he Liu

2015-01-01

Full Text Available Objective. The effects of Flos Puerariae extract (FPE on cognitive impairment associated with diabetes were assessed in C57BL/6J mice. Methods. Experimental diabetic mice model was induced by one injection of 50 mg/kg streptozotocin (STZ for 5 days consecutively. FPE was orally administrated at the dosages of 50, 100, or 200 mg/kg/day, respectively. The learning and memory ability was assessed by Morris water maze test. Body weight, blood glucose, free fatty acid (FFA and total cholesterol (TCH in serum, malondialdehyde (MDA, superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GSH-Px, and acetylcholinesterase (AChE activities in cerebral cortex and hippocampus were also measured. Results. Oral administration of FPE significantly improved cognitive deficits in STZ-induced diabetic mice. FPE treatment also maintained body weight and ameliorated hyperglycemia and dyslipidemia in diabetic mice. Additionally, decreased MDA level, enhanced CAT, and GSH-Px activities in cerebral cortex or hippocampus, as well as alleviated AChE activity in cerebral cortex, were found in diabetic mice supplemented with FPE. Conclusion. This study suggests that FPE ameliorates memory deficits in experimental diabetic mice, at least partly through the normalization of metabolic abnormalities, ameliorated oxidative stress, and AChE activity in brain.

Memory-impairing effects of local anesthetics in an elevated plus-maze test in mice

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S.L. Blatt

1998-04-01

Full Text Available Post-training intracerebroventricular administration of procaine (20 µg/µl and dimethocaine (10 or 20 µg/µl, local anesthetics of the ester class, prolonged the latency (s in the retention test of male and female 3-month-old Swiss albino mice (25-35 g body weight; N = 140 in the elevated plus-maze (mean ± SEM for 10 male mice: control = 41.2 ± 8.1; procaine = 78.5 ± 10.3; 10 µg/µl dimethocaine = 58.7 ± 12.3; 20 µg/µl dimethocaine = 109.6 ± 5.73; for 10 female mice: control = 34.8 ± 5.8; procaine = 55.3 ± 13.4; 10 µg/µl dimethocaine = 59.9 ± 12.3 and 20 µg/µl dimethocaine = 61.3 ± 11.1. However, lidocaine (10 or 20 µg/µl, an amide class type of local anesthetic, failed to influence this parameter. Local anesthetics at the dose range used did not affect the motor coordination of mice exposed to the rota-rod test. These results suggest that procaine and dimethocaine impair some memory process(es in the plus-maze test. These findings are interpreted in terms of non-anesthetic mechanisms of action of these drugs on memory impairment and also confirm the validity of the elevated plus-maze for the evaluation of drugs affecting learning and memory in mice

Mice Deficient in lysophosphatidic acid acyltransferase delta (Lpaatδ)/acylglycerophosphate acyltransferase 4 (Agpat4) Have Impaired Learning and Memory.

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Bradley, Ryan M; Mardian, Emily B; Bloemberg, Darin; Aristizabal Henao, Juan J; Mitchell, Andrew S; Marvyn, Phillip M; Moes, Katherine A; Stark, Ken D; Quadrilatero, Joe; Duncan, Robin E

2017-11-15

We previously characterized LPAATδ/AGPAT4 as a mitochondrial lysophosphatidic acid acyltransferase that regulates brain levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI). Here, we report that Lpaat δ -/- mice display impaired spatial learning and memory compared to wild-type littermates in the Morris water maze and our investigation of potential mechanisms associated with brain phospholipid changes. Marker protein immunoblotting suggested that the relative brain content of neurons, glia, and oligodendrocytes was unchanged. Relative abundance of the important brain fatty acid docosahexaenoic acid was also unchanged in phosphatidylserine, phosphatidylglycerol, and cardiolipin, in agreement with prior data on PC, PE and PI. In phosphatidic acid, it was increased. Specific decreases in ethanolamine-containing phospholipids were detected in mitochondrial lipids, but the function of brain mitochondria in Lpaat δ -/- mice was unchanged. Importantly, we found that Lpaat δ -/- mice have a significantly and drastically lower brain content of the N -methyl-d-asparate (NMDA) receptor subunits NR1, NR2A, and NR2B, as well as the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluR1, compared to wild-type mice. However, general dysregulation of PI-mediated signaling is not likely responsible, since phospho-AKT and phospho-mTOR pathway regulation was unaffected. Our findings indicate that Lpaat δ deficiency causes deficits in learning and memory associated with reduced NMDA and AMPA receptors. Copyright © 2017 American Society for Microbiology.

XBP1 (X-Box-Binding Protein-1)-Dependent O-GlcNAcylation Is Neuroprotective in Ischemic Stroke in Young Mice and Its Impairment in Aged Mice Is Rescued by Thiamet-G.

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Jiang, Meng; Yu, Shu; Yu, Zhui; Sheng, Huaxin; Li, Ying; Liu, Shuai; Warner, David S; Paschen, Wulf; Yang, Wei

2017-06-01

Impaired protein homeostasis induced by endoplasmic reticulum dysfunction is a key feature of a variety of age-related brain diseases including stroke. To restore endoplasmic reticulum function impaired by stress, the unfolded protein response is activated. A key unfolded protein response prosurvival pathway is controlled by the endoplasmic reticulum stress sensor (inositol-requiring enzyme-1), XBP1 (downstream X-box-binding protein-1), and O-GlcNAc (O-linked β-N-acetylglucosamine) modification of proteins (O-GlcNAcylation). Stroke impairs endoplasmic reticulum function, which activates unfolded protein response. The rationale of this study was to explore the potentials of the IRE1/XBP1/O-GlcNAc axis as a target for neuroprotection in ischemic stroke. Mice with Xbp1 loss and gain of function in neurons were generated. Stroke was induced by transient or permanent occlusion of the middle cerebral artery in young and aged mice. Thiamet-G was used to increase O-GlcNAcylation. Deletion of Xbp1 worsened outcome after transient and permanent middle cerebral artery occlusion. After stroke, O-GlcNAcylation was activated in neurons of the stroke penumbra in young mice, which was largely Xbp1 dependent. This activation of O-GlcNAcylation was impaired in aged mice. Pharmacological increase of O-GlcNAcylation before or after stroke improved outcome in both young and aged mice. Our study indicates a critical role for the IRE1/XBP1 unfolded protein response branch in stroke outcome. O-GlcNAcylation is a prosurvival pathway that is activated in the stroke penumbra in young mice but impaired in aged mice. Boosting prosurvival pathways to counterbalance the age-related decline in the brain's self-healing capacity could be a promising strategy to improve ischemic stroke outcome in aged brains. © 2017 American Heart Association, Inc.

Impaired Leptomeningeal Collateral Flow Contributes to the Poor Outcome following Experimental Stroke in the Type 2 Diabetic Mice

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Akamatsu, Yosuke; Nishijima, Yasuo; Lee, Chih Cheng; Yang, Shih Yen; Shi, Lei; An, Lin; Wang, Ruikang K.; Tominaga, Teiji

2015-01-01

Collateral status is an independent predictor of stroke outcome. However, the spatiotemporal manner in which collateral flow maintains cerebral perfusion during cerebral ischemia is poorly understood. Diabetes exacerbates ischemic brain damage, although the impact of diabetes on collateral dynamics remains to be established. Using Doppler optical coherent tomography, a robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, and it continued to grow over the course of 1 week. In contrast, an impairment of collateral recruitment was evident in the Type 2 diabetic db/db mice, which coincided with a worse stroke outcome compared with their normoglycemic counterpart db/+, despite their equally well-collateralized leptomeningeal anastomoses. Similar to the wild-type mice, both db/+ and db/db mice underwent collateral growth 7 d after MCA stroke, although db/db mice still exhibited significantly reduced retrograde flow into the MCA territory chronically. Acutely induced hyperglycemia in the db/+ mice did not impair collateral flow after stroke, suggesting that the state of hyperglycemia alone was not sufficient to impact collateral flow. Human albumin was efficacious in improving collateral flow and outcome after stroke in the db/db mice, enabling perfusion to proximal MCA territory that was usually not reached by retrograde flow from anterior cerebral artery without treatment. Our results suggest that the impaired collateral status contributes to the exacerbated ischemic injury in mice with Type 2 diabetes, and modulation of collateral flow has beneficial effects on stroke outcome among these subjects. PMID:25740515

Quercetin Affects Erythropoiesis and Heart Mitochondrial Function in Mice

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Lina M. Ruiz

2015-01-01

Full Text Available Quercetin, a dietary flavonoid used as a food supplement, showed powerful antioxidant effects in different cellular models. However, recent in vitro and in vivo studies in mammals have suggested a prooxidant effect of quercetin and described an interaction with mitochondria causing an increase in O2∙- production, a decrease in ATP levels, and impairment of respiratory chain in liver tissue. Therefore, because of its dual actions, we studied the effect of quercetin in vivo to analyze heart mitochondrial function and erythropoiesis. Mice were injected with 50 mg/kg of quercetin for 15 days. Treatment with quercetin decreased body weight, serum insulin, and ceruloplasmin levels as compared with untreated mice. Along with an impaired antioxidant capacity in plasma, quercetin-treated mice showed a significant delay on erythropoiesis progression. Heart mitochondrial function was also impaired displaying more protein oxidation and less activity for IV, respectively, than no-treated mice. In addition, a significant reduction in the protein expression levels of Mitofusin 2 and Voltage-Dependent Anion Carrier was observed. All these results suggest that quercetin affects erythropoiesis and mitochondrial function and then its potential use as a dietary supplement should be reexamined.

Impaired IL-13-mediated functions of macrophages in STAT6-deficient mice.

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Takeda, K; Kamanaka, M; Tanaka, T; Kishimoto, T; Akira, S

1996-10-15

IL-13 shares many biologic responses with IL-4. In contrast to well-characterized IL-4 signaling pathways, which utilize STAT6 and 4PS/IRS2, IL-13 signaling pathways are poorly understood. Recent studies performed with STAT6-deficient mice have demonstrated that STAT6 plays an essential role in IL-4 signaling. In this study, the functions of peritoneal macrophages of STAT6-deficient mice in response to IL-13 were analyzed. In STAT6-deficient mice, neither morphologic changes nor augmentation of MHC class II expression in response to IL-13 was observed. In addition, IL-13 did not decrease the nitric oxide production by activated macrophages. Taken together, these results suggest that the macrophage functions in response to IL-13 were impaired in STAT6-deficient mice, indicating that IL-13 and IL-4 share the signaling pathway via STAT6.

IGF-1 deficiency impairs neurovascular coupling in mice: implications for cerebromicrovascular aging.

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Toth, Peter; Tarantini, Stefano; Ashpole, Nicole M; Tucsek, Zsuzsanna; Milne, Ginger L; Valcarcel-Ares, Noa M; Menyhart, Akos; Farkas, Eszter; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

2015-12-01

Aging is associated with marked deficiency in circulating IGF-1, which has been shown to contribute to age-related cognitive decline. Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of age-related cognitive impairment. To establish the link between IGF-1 deficiency and cerebromicrovascular impairment, neurovascular coupling mechanisms were studied in a novel mouse model of IGF-1 deficiency (Igf1(f/f) -TBG-Cre-AAV8) and accelerated vascular aging. We found that IGF-1-deficient mice exhibit neurovascular uncoupling and show a deficit in hippocampal-dependent spatial memory test, mimicking the aging phenotype. IGF-1 deficiency significantly impaired cerebromicrovascular endothelial function decreasing NO mediation of neurovascular coupling. IGF-1 deficiency also impaired glutamate-mediated CBF responses, likely due to dysregulation of astrocytic expression of metabotropic glutamate receptors and impairing mediation of CBF responses by eicosanoid gliotransmitters. Collectively, we demonstrate that IGF-1 deficiency promotes cerebromicrovascular dysfunction and neurovascular uncoupling mimicking the aging phenotype, which are likely to contribute to cognitive impairment. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Natural amyloid-β oligomers acutely impair the formation of a contextual fear memory in mice.

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Kara A Kittelberger

Full Text Available Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD. It has been proposed that soluble amyloid-beta (Abeta oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss.

Mice Lacking EGR1 Have Impaired Clock Gene (BMAL1) Oscillation, Locomotor Activity, and Body Temperature.

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Riedel, Casper Schwartz; Georg, Birgitte; Jørgensen, Henrik L; Hannibal, Jens; Fahrenkrug, Jan

2018-01-01

Early growth response transcription factor 1 (EGR1) is expressed in the suprachiasmatic nucleus (SCN) after light stimulation. We used EGR1-deficient mice to address the role of EGR1 in the clock function and light-induced resetting of the clock. The diurnal rhythms of expression of the clock genes BMAL1 and PER1 in the SCN were evaluated by semi-quantitative in situ hybridization. We found no difference in the expression of PER1 mRNA between wildtype and EGR1-deficient mice; however, the daily rhythm of BMAL1 mRNA was completely abolished in the EGR1-deficient mice. In addition, we evaluated the circadian running wheel activity, telemetric locomotor activity, and core body temperature of the mice. Loss of EGR1 neither altered light-induced phase shifts at subjective night nor affected negative masking. Overall, circadian light entrainment was found in EGR1-deficient mice but they displayed a reduced locomotor activity and an altered temperature regulation compared to wild type mice. When placed in running wheels, a subpopulation of EGR1-deficient mice displayed a more disrupted activity rhythm with no measurable endogenous period length (tau). In conclusion, the present study provides the first evidence that the circadian clock in the SCN is disturbed in mice deficient of EGR1.

Baculovirus virions displaying Plasmodium berghei circumsporozoite protein protect mice against malaria sporozoite infection

International Nuclear Information System (INIS)

Yoshida, Shigeto; Kondoh, Daisuke; Arai, Eriko; Matsuoka, Hiroyuki; Seki, Chisato; Tanaka, Takao; Okada, Masaji; Ishii, Akira

2003-01-01

The display of foreign proteins on the surface of baculovirus virions has provided a tool for the analysis of protein-protein interactions and for cell-specific targeting in gene transfer applications. To evaluate the baculovirus display system as a vaccine vehicle, we have generated a recombinant baculovirus (AcNPV-CSPsurf) that displays rodent malaria Plasmodium berghei circumsporozoite protein (PbCSP) on the virion surface as a fusion protein with the major baculovirus envelope glycoprotein gp64. The PbCSP-gp64 fusion protein was incorporated and oligomerized on the virion surface and led to a 12-fold increase in the binding activity of AcNPV-CSPsurf virions to HepG2 cells. Immunization with adjuvant-free AcNPV-CSPsurf virions induced high levels of antibodies and gamma interferon-secreting cells against PbCSP and protected 60% of mice against sporozoite challenge. These data demonstrate that AcNPV-CSPsurf displays sporozoite-like PbCSP on the virion surface and possesses dual potentials as a malaria vaccine candidate and a liver-directed gene delivery vehicle

Akita spontaneously type 1 diabetic mice exhibit elevated vascular arginase and impaired vascular endothelial and nitrergic function.

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Toque, Haroldo A; Nunes, Kenia P; Yao, Lin; Xu, Zhimin; Kondrikov, Dmitry; Su, Yunchao; Webb, R Clinton; Caldwell, Ruth B; Caldwell, R William

2013-01-01

Elevated arginase (Arg) activity is reported to be involved in diabetes-induced vascular endothelial dysfunction. It can reduce L-arginine availability to nitric oxide (NO) synthase (NOS) and NO production. Akita mice, a genetic non-obese type 1 diabetes model, recapitulate human diabetes. We determined the role of Arg in a time-course of diabetes-associated endothelial dysfunction in aorta and corpora cavernosa (CC) from Akita mice. Endothelium-dependent relaxation, Arg and NOS activity, and protein expression levels of Arg and constitutive NOS were assessed in aortas and CC from Akita and non-diabetic wild type (WT) mice at 4, 12 and 24 wks of age. Systolic blood pressure (SBP) was assessed by tail cuff. In aorta and CC, Akita mice exhibited a progressive impairment of vascular endothelial and nitrergic function increased Arg activity and expression (Arg1 in aorta and both Arg1 and Arg2 in CC) compared with that of age-matched WT mice. Treatment of aorta and CC from Akita mice with an Arg inhibitor (BEC or ABH) reduced diabetes-induced elevation of Arg activity and restored endothelial and nitrergic function. Reduced levels of phospho-eNOS at Ser(1177) (in aorta and CC) and nNOS expression (in CC) were observed in Akita mice at 12 and 24 wks. Akita mice also had decreased NOS activity in aorta and CC at 12 and 24 wks that was restored by BEC treatment. Further, Akita mice exhibited moderately increased SBP at 24 wks and increased sensitivity to PE-induced contractions in aorta and sympathetic nerve stimulation in CC at 12 and 24 wks. Over 24 wks of diabetes in Akita mice, both aortic and cavernosal tissues exhibited increased Arg activity/expression, contributing to impaired endothelial and nitrergic function and reduced NO production. Our findings demonstrate involvement of Arg activity in diabetes-induced impairment of vascular function in Akita mouse.

Akita spontaneously type 1 diabetic mice exhibit elevated vascular arginase and impaired vascular endothelial and nitrergic function.

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Haroldo A Toque

Full Text Available Elevated arginase (Arg activity is reported to be involved in diabetes-induced vascular endothelial dysfunction. It can reduce L-arginine availability to nitric oxide (NO synthase (NOS and NO production. Akita mice, a genetic non-obese type 1 diabetes model, recapitulate human diabetes. We determined the role of Arg in a time-course of diabetes-associated endothelial dysfunction in aorta and corpora cavernosa (CC from Akita mice.Endothelium-dependent relaxation, Arg and NOS activity, and protein expression levels of Arg and constitutive NOS were assessed in aortas and CC from Akita and non-diabetic wild type (WT mice at 4, 12 and 24 wks of age. Systolic blood pressure (SBP was assessed by tail cuff. In aorta and CC, Akita mice exhibited a progressive impairment of vascular endothelial and nitrergic function increased Arg activity and expression (Arg1 in aorta and both Arg1 and Arg2 in CC compared with that of age-matched WT mice. Treatment of aorta and CC from Akita mice with an Arg inhibitor (BEC or ABH reduced diabetes-induced elevation of Arg activity and restored endothelial and nitrergic function. Reduced levels of phospho-eNOS at Ser(1177 (in aorta and CC and nNOS expression (in CC were observed in Akita mice at 12 and 24 wks. Akita mice also had decreased NOS activity in aorta and CC at 12 and 24 wks that was restored by BEC treatment. Further, Akita mice exhibited moderately increased SBP at 24 wks and increased sensitivity to PE-induced contractions in aorta and sympathetic nerve stimulation in CC at 12 and 24 wks.Over 24 wks of diabetes in Akita mice, both aortic and cavernosal tissues exhibited increased Arg activity/expression, contributing to impaired endothelial and nitrergic function and reduced NO production. Our findings demonstrate involvement of Arg activity in diabetes-induced impairment of vascular function in Akita mouse.

Age- and gender-dependent impairments of neurobehaviors in mice whose mothers were exposed to lipopolysaccharide during pregnancy.

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Wang, Hua; Meng, Xiu-Hong; Ning, Huan; Zhao, Xian-Feng; Wang, Qun; Liu, Ping; Zhang, Heng; Zhang, Cheng; Chen, Gui-Hai; Xu, De-Xiang

2010-02-01

Lipopolysaccharide (LPS)-induced intrauterine infection has been associated with neurodevelopmental injury in rodents. The purpose of the present study was to analyze the dynamic changes of neurobehaviors in mice whose mothers were exposed to LPS during pregnancy. The pregnant mice were intraperitoneally (i.p.) injected with LPS (8 microg/kg) daily from gestational day (gd) 8 to gd 15. A battery of neurobehavioral tasks was performed in mice at postnatal day (PND) 70, 200, 400 and 600. Results showed that the spatial learning and memory ability, determined by radial six-arm water maze (RAWM), were obviously impaired in two hundred-day-old female mice and four hundred-day-old male mice whose mothers were exposed to LPS during pregnancy. Open field test showed that the number of squares crossed and peripheral time, a marker of anxiety and exploration activity, were markedly increased in two hundred-day-old female mice following prenatal LPS exposure. In addition, prenatal LPS exposure significantly shortened the latency to the first grid crossing in six hundred-day-old female offspring. Moreover, sensorimotor impairment in the beam walking was observed in two hundred-day-old female mice whose mothers were exposed to LPS during pregnancy. Species-typical behavior examination showed that prenatal LPS exposure markedly increased weight burrowed in seventy-day-old male offspring and six hundred-day-old female offspring. Correspondingly, prenatal LPS exposure significantly reduced weight hoarded in two hundred-day-old female offspring. Taken together, these results suggest that prenatal LPS exposure induces neurobehavioral impairments at adulthood in an age- and gender-dependent manner. 2009 Elsevier Ireland Ltd. All rights reserved.

Mice lacking prostaglandin E receptor subtype 4 manifest disrupted lipid metabolism attributable to impaired triglyceride clearance.

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Cai, Yin; Ying, Fan; Song, Erfei; Wang, Yu; Xu, Aimin; Vanhoutte, Paul M; Tang, Eva Hoi-Ching

2015-12-01

Upon high-fat feeding, prostaglandin E receptor subtype 4 (EP4)-knockout mice gain less body weight than their EP4(+/+) littermates. We investigated the cause of the lean phenotype. The mice showed a 68.8% reduction in weight gain with diminished fat mass that was not attributable to reduced food intake, fat malabsorption, or increased energy expenditure. Plasma triglycerides in the mice were elevated by 244.9%. The increase in plasma triglycerides was independent of changes in hepatic very low density lipoprotein (VLDL)-triglyceride production or intestinal chylomicron-triglyceride synthesis. However, VLDL-triglyceride clearance was drastically impaired in the EP4-knockout mice. The absence of EP4 in mice compromised the activation of lipoprotein lipase (LPL), the key enzyme responsible for trafficking of plasma triglycerides into peripheral tissues. Deficiency in EP4 reduced hepatic mRNA expression of the transcriptional factor cAMP response element binding protein H (by 36.8%) and LPL activators, including apolipoprotein (Apo)a5 (by 40.2%) and Apoc2 (by 61.3%). In summary, the lean phenotype of EP4-deficient mice resulted from reduction in adipose tissue and accretion of other peripheral organs caused by impaired triglyceride clearance. The findings identify a new metabolic dimension in the physiologic role played by endogenous EP4. © FASEB.

Puerarin attenuates learning and memory impairments and inhibits oxidative stress in STZ-induced SAD mice.

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Zhao, Shan-shan; Yang, Wei-na; Jin, Hui; Ma, Kai-ge; Feng, Gai-feng

2015-12-01

Puerarin (PUE), an isoflavone purified from the root of Pueraria lobata (Chinese herb), has been reported to attenuate learning and memory impairments in the transgenic mouse model of Alzheimer's disease (AD). In the present study, we tested PUE in a sporadic AD (SAD) mouse model which was induced by the intracerebroventricular injection of streptozotocin (STZ). The mice were administrated PUE (25, 50, or 100mg/kg/d) for 28 days. Learning and memory abilities were assessed by the Morris water maze test. After behavioral test, the biochemical parameters of oxidative stress (glutathione peroxidase (GSH-Px), superoxide dismutases (SOD), and malondialdehyde (MDA)) were measured in the cerebral cortex and hippocampus. The SAD mice exhibited significantly decreased learning and memory ability, while PUE attenuated these impairments. The activities of GSH-Px and SOD were decreased while MDA was increased in the SAD animals. After PUE treatment, the activities of GSH-Px and SOD were elevated, and the level of MDA was decreased. The middle dose PUE was more effective than others. These results indicate that PUE attenuates learning and memory impairments and inhibits oxidative stress in STZ-induced SAD mice. PUE may be a promising therapeutic agent for SAD. Copyright © 2015 Elsevier Inc. All rights reserved.

Disruption of BCAA metabolism in mice impairs exercise metabolism and endurance.

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She, Pengxiang; Zhou, Yingsheng; Zhang, Zhiyou; Griffin, Kathleen; Gowda, Kavitha; Lynch, Christopher J

2010-04-01

Exercise enhances branched-chain amino acid (BCAA) catabolism, and BCAA supplementation influences exercise metabolism. However, it remains controversial whether BCAA supplementation improves exercise endurance, and unknown whether the exercise endurance effect of BCAA supplementation requires catabolism of these amino acids. Therefore, we examined exercise capacity and intermediary metabolism in skeletal muscle of knockout (KO) mice of mitochondrial branched-chain aminotransferase (BCATm), which catalyzes the first step of BCAA catabolism. We found that BCATm KO mice were exercise intolerant with markedly decreased endurance to exhaustion. Their plasma lactate and lactate-to-pyruvate ratio in skeletal muscle during exercise and lactate release from hindlimb perfused with high concentrations of insulin and glucose were significantly higher in KO than wild-type (WT) mice. Plasma and muscle ammonia concentrations were also markedly higher in KO than WT mice during a brief bout of exercise. BCATm KO mice exhibited 43-79% declines in the muscle concentration of alanine, glutamine, aspartate, and glutamate at rest and during exercise. In response to exercise, the increments in muscle malate and alpha-ketoglutarate were greater in KO than WT mice. While muscle ATP concentration tended to be lower, muscle IMP concentration was sevenfold higher in KO compared with WT mice after a brief bout of exercise, suggesting elevated ammonia in KO is derived from the purine nucleotide cycle. These data suggest that disruption of BCAA transamination causes impaired malate/aspartate shuttle, thereby resulting in decreased alanine and glutamine formation, as well as increases in lactate-to-pyruvate ratio and ammonia in skeletal muscle. Thus BCAA metabolism may regulate exercise capacity in mice.

Autism-related behavioral abnormalities in synapsin knockout mice.

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Greco, Barbara; Managò, Francesca; Tucci, Valter; Kao, Hung-Teh; Valtorta, Flavia; Benfenati, Fabio

2013-08-15

Several synaptic genes predisposing to autism-spectrum disorder (ASD) have been identified. Nonsense and missense mutations in the SYN1 gene encoding for Synapsin I have been identified in families segregating for idiopathic epilepsy and ASD and genetic mapping analyses have identified variations in the SYN2 gene as significantly contributing to epilepsy predisposition. Synapsins (Syn I/II/III) are a multigene family of synaptic vesicle-associated phosphoproteins playing multiple roles in synaptic development, transmission and plasticity. Lack of SynI and/or SynII triggers a strong epileptic phenotype in mice associated with mild cognitive impairments that are also present in the non-epileptic SynIII(-/-) mice. SynII(-/-) and SynIII(-/-) mice also display schizophrenia-like traits, suggesting that Syns could be involved in the regulation of social behavior. Here, we studied social interaction and novelty, social recognition and social dominance, social transmission of food preference and social memory in groups of male SynI(-/-), SynII(-/-) and SynIII(-/-) mice before and after the appearance of the epileptic phenotype and compared their performances with control mice. We found that deletion of Syn isoforms widely impairs social behaviors and repetitive behaviors, resulting in ASD-related phenotypes. SynI or SynIII deletion altered social behavior, whereas SynII deletion extensively impaired various aspects of social behavior and memory, altered exploration of a novel environment and increased self-grooming. Social impairments of SynI(-/-) and SynII(-/-) mice were evident also before the onset of seizures. The results demonstrate an involvement of Syns in generation of the behavioral traits of ASD and identify Syn knockout mice as a useful experimental model of ASD and epilepsy. Copyright © 2013 Elsevier B.V. All rights reserved.

Mutation of Dcdc2 in mice leads to impairments in auditory processing and memory ability.

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Truong, D T; Che, A; Rendall, A R; Szalkowski, C E; LoTurco, J J; Galaburda, A M; Holly Fitch, R

2014-11-01

Dyslexia is a complex neurodevelopmental disorder characterized by impaired reading ability despite normal intellect, and is associated with specific difficulties in phonological and rapid auditory processing (RAP), visual attention and working memory. Genetic variants in Doublecortin domain-containing protein 2 (DCDC2) have been associated with dyslexia, impairments in phonological processing and in short-term/working memory. The purpose of this study was to determine whether sensory and behavioral impairments can result directly from mutation of the Dcdc2 gene in mice. Several behavioral tasks, including a modified pre-pulse inhibition paradigm (to examine auditory processing), a 4/8 radial arm maze (to assess/dissociate working vs. reference memory) and rotarod (to examine sensorimotor ability and motor learning), were used to assess the effects of Dcdc2 mutation. Behavioral results revealed deficits in RAP, working memory and reference memory in Dcdc2(del2/del2) mice when compared with matched wild types. Current findings parallel clinical research linking genetic variants of DCDC2 with specific impairments of phonological processing and memory ability. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Dextran sulfate sodium-induced acute colitis impairs dermal lymphatic function in mice.

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Agollah, Germaine D; Wu, Grace; Peng, Ho-Lan; Kwon, Sunkuk

2015-12-07

To investigate whether dermal lymphatic function and architecture are systemically altered in dextran sulfate sodium (DSS)-induced acute colitis. Balb/c mice were administered 4% DSS in lieu of drinking water ad libitum for 7 d and monitored to assess disease activity including body weight, diarrhea severity, and fecal bleeding. Control mice received standard drinking water with no DSS. Changes in mesenteric lymphatics were assessed following oral administration of a fluorescently-labelled fatty acid analogue, while dermal lymphatic function and architecture was longitudinally characterized using dynamic near-infrared fluorescence (NIRF) imaging following intradermal injection of indocyanine green (ICG) at the base of the tail or to the dorsal aspect of the left paw prior to, 4, and 7 d after DSS administration. We also measured dye clearance rate after injection of Alexa680-bovine serum albumin (BSA). NIRF imaging data was analyzed to reveal lymphatic contractile activity after selecting fixed regions of interest (ROIs) of the same size in fluorescent lymphatic vessels on fluorescence images. The averaged fluorescence intensity within the ROI of each fluorescence image was plotted as a function of imaging time and the lymphatic contraction frequency was computed by assessing the number of fluorescent pulses arriving at a ROI. Mice treated with DSS developed acute inflammation with clinical symptoms of loss of body weight, loose feces/watery diarrhea, and fecal blood, all of which were aggravated as disease progressed to 7 d. Histological examination of colons of DSS-treated mice confirmed acute inflammation, characterized by segmental to complete loss of colonic mucosa with an associated chronic inflammatory cell infiltrate that extended into the deeper layers of the wall of the colon, compared to control mice. In situ intravital imaging revealed that mice with acute colitis showed significantly fewer fluorescent mesenteric lymphatic vessels, indicating impaired

Conditional expression of constitutively active estrogen receptor {alpha} in chondrocytes impairs longitudinal bone growth in mice

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Ikeda, Kazuhiro [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Tsukui, Tohru [Experimental Animal Laboratory, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Imazawa, Yukiko; Horie-Inoue, Kuniko [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Inoue, Satoshi, E-mail: INOUE-GER@h.u-tokyo.ac.jp [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan); Department of Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan)

2012-09-07

Highlights: Black-Right-Pointing-Pointer Conditional transgenic mice expressing constitutively active estrogen receptor {alpha} (caER{alpha}) in chondrocytes were developed. Black-Right-Pointing-Pointer Expression of caER{alpha} in chondrocytes impaired longitudinal bone growth in mice. Black-Right-Pointing-Pointer caER{alpha} affects chondrocyte proliferation and differentiation. Black-Right-Pointing-Pointer This mouse model is useful for understanding the physiological role of ER{alpha}in vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caER{alpha}{sup ColII}, expressing constitutively active mutant estrogen receptor (ER) {alpha} in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caER{alpha}{sup ColII} mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caER{alpha}{sup ColII} mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caER{alpha}{sup ColII} mice. These results suggest that ER{alpha} is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.

Citalopram Ameliorates Impairments in Spatial Memory and Synaptic Plasticity in Female 3xTgAD Mice

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Zhang Wei

2017-01-01

Full Text Available Alzheimer’s disease (AD is the primary cause of dementia. There is no effective treatment. Amyloid-β peptide (Aβ plays an important role in the pathogenesis and thus strategies suppressing Aβ production and accumulation seem promising. Citalopram is an antidepressant drug and can decrease Aβ production and amyloid plaques in transgenic mice of AD and humans. Whether citalopram can ameliorate memory deficit was not known yet. We tested the effects of citalopram on behavioral performance and synaptic plasticity in female 3xTgAD mice, a well-characterized model of AD. Mice were treated with citalopram or water from 5 months of age for 3 months. Citalopram treatment at approximately 10 mg/kg/day significantly improved spatial memory in the Morris water maze (MWM test, while not affecting anxiety-like and depression-like behavior in 3xTgAD mice. Further, hippocampal long-term potentiation (LTP impairment in 3xTgAD mice was reversed by citalopram treatment. Citalopram treatment also significantly decreased the levels of insoluble Aβ40 in hippocampal and cortical tissues in 3xTgAD mice, accompanied with a reduced amyloid precursor protein (APP. Together, citalopram treatment may be a promising strategy for AD and further clinical trials should be conducted to verify the effect of citalopram on cognition in patients with AD or mild cognitive impairment.

ENU-mutagenesis mice with a non-synonymous mutation in Grin1 exhibit abnormal anxiety-like behaviors, impaired fear memory, and decreased acoustic startle response

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2013-01-01

Background The Grin1 (glutamate receptor, ionotropic, NMDA1) gene expresses a subunit of N-methyl-D-aspartate (NMDA) receptors that is considered to play an important role in excitatory neurotransmission, synaptic plasticity, and brain development. Grin1 is a candidate susceptibility gene for neuropsychiatric disorders, including schizophrenia, bipolar disorder, and attention deficit/hyperactivity disorder (ADHD). In our previous study, we examined an N-ethyl-N-nitrosourea (ENU)-generated mutant mouse strain (Grin1Rgsc174/Grin1+) that has a non-synonymous mutation in Grin1. These mutant mice showed hyperactivity, increased novelty-seeking to objects, and abnormal social interactions. Therefore, Grin1Rgsc174/Grin1+ mice may serve as a potential animal model of neuropsychiatric disorders. However, other behavioral characteristics related to these disorders, such as working memory function and sensorimotor gating, have not been fully explored in these mutant mice. In this study, to further investigate the behavioral phenotypes of Grin1Rgsc174/Grin1+ mice, we subjected them to a comprehensive battery of behavioral tests. Results There was no significant difference in nociception between Grin1Rgsc174/Grin1+ and wild-type mice. The mutants did not display any abnormalities in the Porsolt forced swim and tail suspension tests. We confirmed the previous observations that the locomotor activity of these mutant mice increased in the open field and home cage activity tests. They displayed abnormal anxiety-like behaviors in the light/dark transition and the elevated plus maze tests. Both contextual and cued fear memory were severely deficient in the fear conditioning test. The mutant mice exhibited slightly impaired working memory in the eight-arm radial maze test. The startle amplitude was markedly decreased in Grin1Rgsc174/Grin1+ mice, whereas no significant differences between genotypes were detected in the prepulse inhibition (PPI) test. The mutant mice showed no obvious

Cadmium Exposure Impairs Cognition and Olfactory Memory in Male C57BL/6 Mice.

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Wang, Hao; Zhang, Liang; Abel, Glen M; Storm, Daniel R; Xia, Zhengui

2018-01-01

Cadmium (Cd) is a heavy metal of high interest to the superfund initiative. Recent epidemiology studies have suggested a possible association between Cd exposure and cognitive as well as olfactory impairments in humans. However, studies in animal models are needed to establish a direct causal relationship between Cd exposure and impairments in cognition and olfaction. This study aims to investigate the toxic effect of Cd on cognition and olfactory function in mice. One group of 8-week-old C57BL/6 male mice was exposed to 3 mg/l Cd (in the form of CdCl2) through drinking water for 20 weeks for behavior tests and final blood Cd concentration analysis. The behavior tests were conducted before, during, and after Cd exposure to analyze the effects of Cd on cognition and olfactory function. Upon completion of behavior tests, blood was collected to measure final blood Cd concentration. Two additional groups of mice were similarly exposed to Cd for 5 or 13 weeks for peak blood Cd concentration measurement. The peak blood Cd concentration was 2.125-2.25 μg/l whereas the final blood Cd concentration was 0.18 μg/l. At this exposure level, Cd impaired hippocampus-dependent learning and memory in novel object location test, T-maze test, and contextual fear memory test. It also caused deficits in short-term olfactory memory and odor-cued olfactory learning and memory. Results in this study demonstrate a direct relationship between Cd exposure and cognitive as well as olfactory impairments in an animal model. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Impaired spatial and contextual memory formation in galectin-1 deficient mice

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Sakaguchi Masanori

2011-09-01

Full Text Available Abstract Galectins are a 15 member family of carbohydrate-binding proteins that have been implicated in cancer, immunity, inflammation and development. While galectins are expressed in the central nervous system, little is known about their function in the adult brain. Previously we have shown that galectin-1 (gal-1 is expressed in the adult hippocampus, and, in particular, in putative neural stem cells in the subgranular zone. To evaluate how gal-1 might contribute to hippocampal memory function here we studied galectin-1 null mutant (gal-1-/- mice. Compared to their wildtype littermate controls, gal-1-/- mice exhibited impaired spatial learning in the water maze and contextual fear learning. Interestingly, tone fear conditioning was normal in gal-1-/- mice suggesting that loss of gal-1 might especially impact hippocampal learning and memory. Furthermore, gal-1-/- mice exhibited normal motor function, emotion and sensory processing in a battery of other behavioral tests, suggesting that non-mnemonic performance deficits are unlikely to account for the spatial and contextual learning deficits. Together, these data reveal a role for galectin-carbohydrate signalling in hippocampal memory function.

Adenosine A(2A) receptors are necessary and sufficient to trigger memory impairment in adult mice.

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Pagnussat, N; Almeida, A S; Marques, D M; Nunes, F; Chenet, G C; Botton, P H S; Mioranzza, S; Loss, C M; Cunha, R A; Porciúncula, L O

2015-08-01

Caffeine (a non-selective adenosine receptor antagonist) prevents memory deficits in aging and Alzheimer's disease, an effect mimicked by adenosine A2 A receptor, but not A1 receptor, antagonists. Hence, we investigated the effects of adenosine receptor agonists and antagonists on memory performance and scopolamine-induced memory impairment in mice. We determined whether A2 A receptors are necessary for the emergence of memory impairments induced by scopolamine and whether A2 A receptor activation triggers memory deficits in naïve mice, using three tests to assess short-term memory, namely the object recognition task, inhibitory avoidance and modified Y-maze. Scopolamine (1.0 mg·kg(-1) , i.p.) impaired short-term memory performance in all three tests and this scopolamine-induced amnesia was prevented by the A2 A receptor antagonist (SCH 58261, 0.1-1.0 mg·kg(-1) , i.p.) and by the A1 receptor antagonist (DPCPX, 0.2-5.0 mg·kg(-1) , i.p.), except in the modified Y-maze where only SCH58261 was effective. Both antagonists were devoid of effects on memory or locomotion in naïve rats. Notably, the activation of A2 A receptors with CGS 21680 (0.1-0.5 mg·kg(-1) , i.p.) before the training session was sufficient to trigger memory impairment in the three tests in naïve mice, and this effect was prevented by SCH 58261 (1.0 mg·kg(-1) , i.p.). Furthermore, i.c.v. administration of CGS 21680 (50 nmol) also impaired recognition memory in the object recognition task. These results show that A2 A receptors are necessary and sufficient to trigger memory impairment and further suggest that A1 receptors might also be selectively engaged to control the cholinergic-driven memory impairment. © 2015 The British Pharmacological Society.

Dietary long chain n-3 polyunsaturated fatty acids prevent impaired social behaviour and normalize brain dopamine levels in food allergic mice.

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de Theije, Caroline G M; van den Elsen, Lieke W J; Willemsen, Linette E M; Milosevic, Vanja; Korte-Bouws, Gerdien A H; Lopes da Silva, Sofia; Broersen, Laus M; Korte, S Mechiel; Olivier, Berend; Garssen, Johan; Kraneveld, Aletta D

2015-03-01

Allergy is suggested to exacerbate impaired behaviour in children with neurodevelopmental disorders. We have previously shown that food allergy impaired social behaviour in mice. Dietary fatty acid composition may affect both the immune and nervous system. The aim of this study was to assess the effect of n-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) on food allergy-induced impaired social behaviour and associated deficits in prefrontal dopamine (DA) in mice. Mice were fed either control or n-3 LCPUFA-enriched diet before and during sensitization with whey. Social behaviour, acute allergic skin response and serum immunoglobulins were assessed. Monoamine levels were measured in brain and intestine and fatty acid content in brain. N-3 LCPUFA prevented impaired social behaviour of allergic mice. Moreover, n-3 LCPUFA supplementation increased docosahexaenoic acid (DHA) incorporation into the brain and restored reduced levels of prefrontal DA and its metabolites 3,4-dihydroxyphenylacetic acid, 3-methoxytyramine and homovanillic acid in allergic mice. In addition to these brain effects, n-3 LCPUFA supplementation reduced the allergic skin response and restored decreased intestinal levels of serotonin metabolite 5-hydroxyindoleacetic acid in allergic mice. N-3 LCPUFA may have beneficial effects on food allergy-induced deficits in social behaviour, either indirectly by reducing the allergic response and restoring intestinal 5-HT signalling, or directly by DHA incorporation into neuronal membranes, affecting the DA system. Therefore, it is of interest to further investigate the relevance of food allergy-enhanced impairments in social behaviour in humans and the potential benefits of dietary n-3 LCPUFA supplementation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Abnormal neural activation patterns underlying working memory impairment in chronic phencyclidine-treated mice.

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Yosefu Arime

Full Text Available Working memory impairment is a hallmark feature of schizophrenia and is thought be caused by dysfunctions in the prefrontal cortex (PFC and associated brain regions. However, the neural circuit anomalies underlying this impairment are poorly understood. The aim of this study is to assess working memory performance in the chronic phencyclidine (PCP mouse model of schizophrenia, and to identify the neural substrates of working memory. To address this issue, we conducted the following experiments for mice after withdrawal from chronic administration (14 days of either saline or PCP (10 mg/kg: (1 a discrete paired-trial variable-delay task in T-maze to assess working memory, and (2 brain-wide c-Fos mapping to identify activated brain regions relevant to this task performance either 90 min or 0 min after the completion of the task, with each time point examined under working memory effort and basal conditions. Correct responses in the test phase of the task were significantly reduced across delays (5, 15, and 30 s in chronic PCP-treated mice compared with chronic saline-treated controls, suggesting delay-independent impairments in working memory in the PCP group. In layer 2-3 of the prelimbic cortex, the number of working memory effort-elicited c-Fos+ cells was significantly higher in the chronic PCP group than in the chronic saline group. The main effect of working memory effort relative to basal conditions was to induce significantly increased c-Fos+ cells in the other layers of prelimbic cortex and the anterior cingulate and infralimbic cortex regardless of the different chronic regimens. Conversely, this working memory effort had a negative effect (fewer c-Fos+ cells in the ventral hippocampus. These results shed light on some putative neural networks relevant to working memory impairments in mice chronically treated with PCP, and emphasize the importance of the layer 2-3 of the prelimbic cortex of the PFC.

Peripheral surgical wounding may induce cognitive impairment through interlukin-6-dependent mechanisms in aged mice

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Dong, Yuanlin; Xu, Zhipeng; Huang, Lining; Zhang, Yiying; Xie, Zhongcong

2016-01-01

Post-operative cognitive dysfunction (POCD) is associated with morbidity, mortality and increased cost of medical care. However, the neuropathogenesis and targeted interventions of POCD remain largely to be determined. We have found that the peripheral surgical wounding induces an age-dependent A? accumulation, neuroinflammation and cognitive impairment in aged mice. Pro-inflammatory cytokine interlukin-6 (IL-6) has been reported to be associated with cognitive impairment in rodents and human...

Delay-dependent working memory impairment in young-adult and aged 5-HT1BKO mice as assessed in a radial-arm water maze.

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Wolff, Mathieu; Benhassine, Narimane; Costet, Pierre; Hen, Rene; Segu, Louis; Buhot, Marie-Christine

2003-01-01

Serotonin (5-HT) plays a modulatory role in mnemonic functions, especially by interacting with the cholinergic system. The 5-HT1B receptor is a key target of this interaction. The 5-HT1B receptor knockout mice were found previously to exhibit a facilitation in hippocampal-dependent spatial reference memory learning. In the present study, we submitted mice to a delayed spatial working memory task, allowing the introduction of various delays between an exposure trial and a test trial. The 5-HT1BKO and wild-type mice learned the task in a radial-arm water maze (returning to the most recent presented arm containing the escape platform), and exhibited a high level of performance at delays of 0 and 5 min. However, at the delay of 60 min, only 5-HT1BKO mice exhibited an impairment. At a delay of 90 min, all mice were impaired. Treatment by scopolamine (0.8 mg/kg) induced the same pattern of performance in wild type as did the mutation for short (5 min, no impairment) and long (60 min, impairment) delays. The 22-month-old wild-type and knockout mice exhibited an impairment at short delays (5 and 15 min). The effect of the mutation affected both young-adult and aged mice at delays of 15, 30, and 60 min. Neurobiological data show that stimulation of the 5-HT1B receptor inhibits the release of acetylcholine in the hippocampus, but stimulates this in the frontal cortex. This dual function might, at least in part, explain the opposite effect of the mutation on reference memory (facilitation) and delay-dependent working memory (impairment). These results support the idea that cholinergic-serotonergic interactions play an important role in memory processes.

Mice deficient in transmembrane prostatic acid phosphatase display increased GABAergic transmission and neurological alterations.

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Heidi O Nousiainen

Full Text Available Prostatic acid phosphatase (PAP, the first diagnostic marker and present therapeutic target for prostate cancer, modulates nociception at the dorsal root ganglia (DRG, but its function in the central nervous system has remained unknown. We studied expression and function of TMPAP (the transmembrane isoform of PAP in the brain by utilizing mice deficient in TMPAP (PAP-/- mice. Here we report that TMPAP is expressed in a subpopulation of cerebral GABAergic neurons, and mice deficient in TMPAP show multiple behavioral and neurochemical features linked to hyperdopaminergic dysregulation and altered GABAergic transmission. In addition to increased anxiety, disturbed prepulse inhibition, increased synthesis of striatal dopamine, and augmented response to amphetamine, PAP-deficient mice have enlarged lateral ventricles, reduced diazepam-induced loss of righting reflex, and increased GABAergic tone in the hippocampus. TMPAP in the mouse brain is localized presynaptically, and colocalized with SNARE-associated protein snapin, a protein involved in synaptic vesicle docking and fusion, and PAP-deficient mice display altered subcellular distribution of snapin. We have previously shown TMPAP to reside in prostatic exosomes and we propose that TMPAP is involved in the control of GABAergic tone in the brain also through exocytosis, and that PAP deficiency produces a distinct neurological phenotype.

A beam-walking apparatus to assess behavioural impairments in MPTP-treated mice: pharmacological validation with R-(-)-deprenyl.

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Quinn, Leann P; Perren, Marion J; Brackenborough, Kim T; Woodhams, Peter L; Vidgeon-Hart, Martin; Chapman, Helen; Pangalos, Menelas N; Upton, Neil; Virley, David J

2007-08-15

A beam-walking apparatus has been evaluated for its ability to detect motor impairments in mice acutely treated with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg, s.c., single or double administration). Mice subjected to MPTP lesioning showed deficits in motor performance on the beam-walking task, for up to 6 days post-MPTP administration, as compared to saline-treated controls. In addition, MPTP-treated mice were detected to have a marked depletion in striatal dopamine levels and a concomitant reduction in substantia nigra (SN) tyrosine hydroxylase (TH) immunoreactivity, at 7 days post-MPTP administration, indicative of dopaminergic neuronal loss. Pre-administration of the potent MAO-B inhibitor R-(-)-deprenyl at 3 or 10 mg/kg, 30 min, s.c, significantly inhibited the MPTP-induced reduction in SN TH-immunoreactivity, striatal dopamine depletions and impairments in mouse motor function. The data described in the present study provides further evidence that functional deficits following an acute MPTP dosing schedule in mice can be quantified and are related to nigro-striatal dopamine function.

Umbilical Cord Blood-Derived Stem Cells Improve Heat Tolerance and Hypothalamic Damage in Heat Stressed Mice

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Ling-Shu Tseng

2014-01-01

Full Text Available Heatstroke is characterized by excessive hyperthermia associated with systemic inflammatory responses, which leads to multiple organ failure, in which brain disorders predominate. This definition can be almost fulfilled by a mouse model of heatstroke used in the present study. Unanesthetized mice were exposed to whole body heating (41.2°C for 1 hour and then returned to room temperature (26°C for recovery. Immediately after termination of whole body heating, heated mice displayed excessive hyperthermia (body core temperature ~42.5°C. Four hours after termination of heat stress, heated mice displayed (i systemic inflammation; (ii ischemic, hypoxic, and oxidative damage to the hypothalamus; (iii hypothalamo-pituitary-adrenocortical axis impairment (reflected by plasma levels of both adrenocorticotrophic-hormone and corticosterone; (iv decreased fractional survival; and (v thermoregulatory deficits (e.g., they became hypothermia when they were exposed to room temperature. These heatstroke reactions can be significantly attenuated by human umbilical cord blood-derived CD34+ cells therapy. Our data suggest that human umbilical cord blood-derived stem cells therapy may improve outcomes of heatstroke in mice by reducing systemic inflammation as well as hypothalamo-pituitary-adrenocortical axis impairment.

Impaired sense of smell and altered olfactory system in RAG-1-/- immunodeficient mice

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Lorenza eRattazzi

2015-09-01

Full Text Available Immune deficiencies are often associated with a number of physical manifestations including loss of sense of smell and an increased level of anxiety. We have previously shown that T and B cell-deficient recombinase activating gene (RAG-1-/- knockout mice have an increased level of anxiety-like behavior and altered gene expression involved in olfaction. In this study, we expanded these findings by testing the structure and functional development of the olfactory system in RAG-1-/- mice. Our results show that these mice have a reduced engagement in different types of odors and this phenotype is associated with disorganized architecture of glomerular tissue and atrophy of the main olfactory epithelium. Most intriguingly this defect manifests specifically in adult age and is not due to impairment in the patterning of the olfactory neuron staining at the embryo stage. Together these findings provide a formerly unreported biological evidence for an altered function of the olfactory system in RAG-1-/- mice.

Impaired hippocampal acetylcholine release parallels spatial memory deficits in Tg2576 mice subjected to basal forebrain cholinergic degeneration

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Laursen, Bettina; Mørk, Arne; Plath, Niels

2013-01-01

(BFCD) in 3 months old male Tg2576 mice to co-express cholinergic degeneration with Aβ overexpression as these characteristics constitutes key hallmarks of AD. At 9 months, SAP lesioned Tg2576 mice were cognitively impaired in two spatial paradigms addressing working memory and mid to long-term memory...

Hormone-sensitive lipase null mice exhibit signs of impaired insulin sensitivity whereas insulin secretion is intact

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Mulder, Hindrik; Sörhede-Winzell, Maria; Contreras, Juan Antonio

2003-01-01

of increased amounts of insulin. Impaired insulin sensitivity was further indicated by retarded glucose disposal during an insulin tolerance test. A euglycemic hyperinsulinemic clamp revealed that hepatic glucose production was insufficiently blocked by insulin in HSL null mice. In vitro, insulin......-stimulated glucose uptake into soleus muscle, and lipogenesis in adipocytes were moderately reduced, suggesting additional sites of insulin resistance. Morphometric analysis of pancreatic islets revealed a doubling of beta-cell mass in HSL null mice, which is consistent with an adaptation to insulin resistance....... Insulin secretion in vitro, examined by perifusion of isolated islets, was not impacted by HSL deficiency. Thus, HSL deficiency results in a moderate impairment of insulin sensitivity in multiple target tissues of the hormone but is compensated by hyperinsulinemia....

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

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Kaidanovich-Beilin Oksana

2009-11-01

Full Text Available Abstract 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.

A high-sugar and high-fat diet impairs cardiac systolic and diastolic function in mice.

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Carbone, Salvatore; Mauro, Adolfo G; Mezzaroma, Eleonora; Kraskauskas, Donatas; Marchetti, Carlo; Buzzetti, Raffaella; Van Tassell, Benjamin W; Abbate, Antonio; Toldo, Stefano

2015-11-01

Heart failure (HF) is a clinical syndrome characterized by dyspnea, fatigue, exercise intolerance and cardiac dysfunction. Unhealthy diet has been associated with increased risk of obesity and heart disease, but whether it directly affects cardiac function, and promotes the development and progression of HF is unknown. We fed 8-week old male or female CD-1 mice with a standard diet (SD) or a diet rich in saturated fat and sugar, resembling a "Western" diet (WD). Cardiac systolic and diastolic function was measured at baseline and 4 and 8 weeks by Doppler echocardiography, and left ventricular (LV) end-diastolic pressure (EDP) by cardiac catheterization prior to sacrifice. An additional group of mice received WD for 4 weeks followed by SD (wash-out) for 8 weeks. WD-fed mice experienced a significant decreased in LV ejection fraction (LVEF), reflecting impaired systolic function, and a significant increase in isovolumetric relaxation time (IRT), myocardial performance index (MPI), and LVEDP, showing impaired diastolic function, without any sex-related differences. Switching to a SD after 4 weeks of WD partially reversed the cardiac systolic and diastolic dysfunction. A diet rich in saturated fat and sugars (WD) impairs cardiac systolic and diastolic function in the mouse. Further studies are required to define the mechanism through which diet affects cardiac function, and whether dietary interventions can be used in patients with, or at risk for, HF. Published by Elsevier Ireland Ltd.

Generation and characterization of mice carrying a conditional allele of the Wwox tumor suppressor gene.

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John H Ludes-Meyers

2009-11-01

Full Text Available WWOX, the gene that spans the second most common human chromosomal fragile site, FRA16D, is inactivated in multiple human cancers and behaves as a suppressor of tumor growth. Since we are interested in understanding WWOX function in both normal and cancer tissues we generated mice harboring a conditional Wwox allele by flanking Exon 1 of the Wwox gene with LoxP sites. Wwox knockout (KO mice were developed by breeding with transgenic mice carrying the Cre-recombinase gene under the control of the adenovirus EIIA promoter. We found that Wwox KO mice suffered from severe metabolic defect(s resulting in growth retardation and all mice died by 3 wk of age. All Wwox KO mice displayed significant hypocapnia suggesting a state of metabolic acidosis. This finding and the known high expression of Wwox in kidney tubules suggest a role for Wwox in acid/base balance. Importantly, Wwox KO mice displayed histopathological and hematological signs of impaired hematopoiesis, leukopenia, and splenic atrophy. Impaired hematopoiesis can also be a contributing factor to metabolic acidosis and death. Hypoglycemia and hypocalcemia was also observed affecting the KO mice. In addition, bone metabolic defects were evident in Wwox KO mice. Bones were smaller and thinner having reduced bone volume as a consequence of a defect in mineralization. No evidence of spontaneous neoplasia was observed in Wwox KO mice. We have generated a new mouse model to inactivate the Wwox tumor suppressor gene conditionally. This will greatly facilitate the functional analysis of Wwox in adult mice and will allow investigating neoplastic transformation in specific target tissues.

Compound danshen tablet ameliorated aβ25-35-induced spatial memory impairment in mice via rescuing imbalance between cytokines and neurotrophins.

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Teng, Yan; Zhang, Meng-Qi; Wang, Wen; Liu, Li-Tao; Zhou, Li-Ming; Miao, Shi-Kun; Wan, Li-Hong

2014-01-14

Compound Danshen Tablet (CDT), a Traditional Chinese Medicine, has recently been reported to improve spatial cognition in a rat model of Alzheimer's disease. However, in vivo neuroprotective mechanism of the CDT in models of spatial memory impairment is not yet evaluated. The present study is aimed to elucidate the cellular mechanism of CDT on Aβ25-35-induced cognitive impairment in mice. Mice were randomly divided into 5 groups: the control group (sham operated), the Aβ25-35 treated group, the positive drug group, and large and small dosage of the CDT groups, respectively. CDT was administered at a dose of 0.81 g/kg and 0.405 g/kg for 3 weeks. The mice in the positive drug group were treated with 0.4 mg/kg of Huperzine A, whereas the mice of the control and Aβ25-35 treated groups were administrated orally with equivalent saline. After 7 days of preventive treatment, mice were subjected to lateral ventricle injection of Aβ25-35 to establish the mice model of Alzheimer's disease. Spatial memory impairment was evaluated by Morris water maze test. Choline acetyltransferase (ChAT) contents in hippocampus and cortex were quantified by ELISA. The levels of cytokines, receptor of activated protein kinase C1 (RACK1) and brain-derived neurotrophic factor (BDNF) in hippocampus were measured by RT-PCR and ELISA. The results showed that Aβ25-35 caused spatial memory impairment as demonstrated by performance in the Morris water maze test. CDT was able to confer a significant improvement in spatial memory, and protect mice from Aβ25-35-induced neurotoxicity. Additionally, CDT also inhibited the increase of TNF-α and IL-6 level, and increased the expression of choline acetyltransferase (ChAT), receptor of activated protein kinase C1 (RACK1) and brain-derived neurotrophic factor (BDNF) in brain as compared to model mice. These findings strongly implicate that CDT may be a useful treatment against learning and memory deficits in mice by rescuing imbalance between cytokines

Differential Effects of Olanzapine and Haloperidol on MK-801-induced Memory Impairment in Mice

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Song, Jae Chun; Seo, Mi Kyoung; Park, Sung Woo; Lee, Jung Goo; Kim, Young Hoon

2016-01-01

Objective We investigated the differential effects of the antipsychotic drugs olanzapine and haloperidol on MK-801-induced memory impairment and neurogenesis in mice. Methods MK-801 (0.1 mg/kg) was administered 20 minutes prior to behavioral testing over 9 days. Beginning on the sixth day of MK-801 treatment, either olanzapine (0.05 mg/kg) or haloperidol (0.05 mg/kg) was administered 40 minutes prior to MK-801 for the final 4 days. Spatial memory performance was measured using a Morris water maze (MWM) test for 9 days (four trials/day). Immunohistochemistry with bromodeoxyuridine (BrdU) was used to identify newborn cells labeled in tissue sections from the dentate gyrus of the hippocampus. Results MK-801 administration over 9 days significantly impaired memory performance in the MWM test compared to untreated controls (p801 also resulted in a decrease in the number of BrdU-labeled cells in the dentate gyrus (28.6%; p801 in mice via the stimulating effects of neurogenesis. PMID:27489382

Impairment in extinction of cued fear memory in syntenin-1 knockout mice.

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Talukdar, Gourango; Inoue, Ran; Yoshida, Tomoyuki; Mori, Hisashi

2018-03-01

Syntenin-1 is a PDZ domain-containing intracellular scaffold protein involved in exosome production, synapse formation, and synaptic plasticity. We tested whether syntenin-1 can regulate learning and memory through its effects on synaptic plasticity. Specifically, we investigated the role of syntenin-1 in contextual and cued fear conditioning and extinction of conditioned fear using syntenin-1 knockout (KO) mice. Genetic disruption of syntenin-1 had little effect on contextual and cued fear memory. However, syntenin-1 KO mice exhibited selective impairment in cued fear extinction retention. This extinction retention deficit in syntenin-1 KO mice was associated with reduced c-Fos-positive neurons in the basolateral amygdala (BLA) and infralimbic cortex (IL) after extinction training and increased c-Fos-positive neurons in the BLA after an extinction retention test. Our results suggest that syntenin-1 plays an important role in extinction of cued fear memory by modulating neuronal activity in the BLA and IL. Copyright © 2018 Elsevier Inc. All rights reserved.

Frontal Lobe Contusion in Mice Chronically Impairs Prefrontal-Dependent Behavior.

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Austin Chou

Full Text Available Traumatic brain injury (TBI is a major cause of chronic disability in the world. Moderate to severe TBI often results in damage to the frontal lobe region and leads to cognitive, emotional, and social behavioral sequelae that negatively affect quality of life. More specifically, TBI patients often develop persistent deficits in social behavior, anxiety, and executive functions such as attention, mental flexibility, and task switching. These deficits are intrinsically associated with prefrontal cortex (PFC functionality. Currently, there is a lack of analogous, behaviorally characterized TBI models for investigating frontal lobe injuries despite the prevalence of focal contusions to the frontal lobe in TBI patients. We used the controlled cortical impact (CCI model in mice to generate a frontal lobe contusion and studied behavioral changes associated with PFC function. We found that unilateral frontal lobe contusion in mice produced long-term impairments to social recognition and reversal learning while having only a minor effect on anxiety and completely sparing rule shifting and hippocampal-dependent behavior.

Vanillin improves scopolamine‑induced memory impairment through restoration of ID1 expression in the mouse hippocampus.

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Lee, Jae-Chul; Kim, In Hye; Cho, Jeong Hwi; Lee, Tae-Kyeong; Park, Joon Ha; Ahn, Ji Hyeon; Shin, Bich Na; Yan, Bing Chun; Kim, Jong-Dai; Jeon, Yong Hwan; Lee, Young Joo; Won, Moo-Ho; Kang, Il Jun

2018-03-01

4-Hydroxy-3-methoxybenzaldehyde (vanillin), contained in a number of species of plant, has been reported to display beneficial effects against brain injuries. In the present study, the impact of vanillin on scopolamine‑induced alterations in cognition and the expression of DNA binding protein inhibitor ID‑1 (ID1), one of the inhibitors of DNA binding/differentiation proteins that regulate gene transcription, in the mouse hippocampus. Mice were treated with 1 mg/kg scopolamine with or without 40 mg/kg vanillin once daily for 4 weeks. Scopolamine‑induced cognitive impairment was observed from 1 week and was deemed to be severe 4 weeks following the administration of scopolamine. However, treatment with vanillin in scopolamine‑treated mice markedly attenuated cognitive impairment 4 weeks following treatment with scopolamine. ID1‑immunoreactive cells were revealed in the hippocampus of vehicle‑treated mice, and were hardly detected 4 weeks following treatment with scopolamine. However, treatment with vanillin in scopolamine‑treated mice markedly restored ID1‑immunoreactive cells and expression 4 weeks subsequent to treatment. The results of the present study suggested that vanillin may be beneficial for cognitive impairment, by preventing the reduction of ID1 expression which may be associated with cognitive impairment.

Syngeneic B16F10 Melanoma Causes Cachexia and Impaired Skeletal Muscle Strength and Locomotor Activity in Mice

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Fabrício A. Voltarelli

2017-09-01

Full Text Available Muscle wasting has been emerging as one of the principal components of cancer cachexia, leading to progressive impairment of work capacity. Despite early stages melanomas rarely promotes weight loss, the appearance of metastatic and/or solid tumor melanoma can leads to cachexia development. Here, we investigated the B16F10 tumor-induced cachexia and its contribution to muscle strength and locomotor-like activity impairment. C57BL/6 mice were subcutaneously injected with 5 × 104 B16F10 melanoma cells or PBS as a Sham negative control. Tumor growth was monitored during a period of 28 days. Compared to Sham mice, tumor group depicts a loss of skeletal muscle, as well as significantly reduced muscle grip strength and epididymal fat mass. This data are in agreement with mild to severe catabolic host response promoted by elevated serum tumor necrosis factor-alpha (TNF-α, interleukin-6 (IL-6 and lactate dehydrogenase (LDH activity. Tumor implantation has also compromised general locomotor activity and decreased exploratory behavior. Likewise, muscle loss, and elevated inflammatory interleukin were associated to muscle strength loss and locomotor activity impairment. In conclusion, our data demonstrated that subcutaneous B16F10 melanoma tumor-driven catabolic state in response to a pro-inflammatory environment that is associated with impaired skeletal muscle strength and decreased locomotor activity in tumor-bearing mice.

Gender-specific impairments on cognitive and behavioral development in mice exposed to fenvalerate during puberty.

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Meng, Xiu-Hong; Liu, Ping; Wang, Hua; Zhao, Xian-Feng; Xu, Zhong-Mei; Chen, Gui-Hai; Xu, De-Xiang

2011-06-24

In human and rodent models, endocrine disrupting chemicals (EDCs) interfere with the development of cognition and behaviors. Fenvalerate is a potential EDC. The purpose of this study was to examine whether pubertal fenvalerate exposure altered behavioral development. Mice were orally administered with either vehicle or fenvalerate (7.5 or 30 mg/kg/day) from postnatal day (PND) 28 to PND56. Learning and memory were assessed by Morris Water Maze. Aggressive performance was evaluated by aggressive behavior test. Anxiety-related activities were detected by three tests: open-field, plus-maze and black-white alley. Sensorimotor function was analyzed using beam walking and tightrope. Results found that the impairment for spatial learning and memory was more severe in fenvalerate-exposed female mice than in male mice. In addition, pubertal fenvalerate exposure inhibited aggressive behavior in males. Moreover, pubertal fenvalerate exposure increased anxiety activities in females. Altogether, these results suggest that pubertal fenvalerate exposure impairs spatial cognition and behavioral development in a gender-dependent manner. These findings identify fenvalerate as candidate environmental risk factors for cognitive and behavioral development, especially in the critical period of development. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Odor preference and olfactory memory are impaired in Olfaxin-deficient mice.

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Islam, Saiful; Ueda, Masashi; Nishida, Emika; Wang, Miao-Xing; Osawa, Masatake; Lee, Dongsoo; Itoh, Masanori; Nakagawa, Kiyomi; Tana; Nakagawa, Toshiyuki

2018-06-01

Olfaxin, which is a BNIP2 and Cdc42GAP homology (BCH) domain-containing protein, is predominantly expressed in mitral and tufted (M/T) cells in the olfactory bulb (OB). Olfaxin and Caytaxin, which share 56.3% amino acid identity, are similar in their glutamatergic terminal localization, kidney-type glutaminase (KGA) interaction, and caspase-3 substrate. Although the deletion of Caytaxin protein causes human Cayman ataxia and ataxia in the mutant mouse, the function of Olfaxin is largely unknown. In this study, we generated Prune2 gene mutant mice (Prune2 Ex16-/- ; knock out [KO] mice) using the CRISPR/Cas9 system, during which the exon 16 containing start codon of Olfaxin mRNA was deleted. Exon 16 has 80 nucleotides and is contained in four of five Prune2 isoforms, including PRUNE2, BMCC1, BNIPXL, and Olfaxin/BMCC1s. The levels of Olfaxin mRNA and Olfaxin protein in the OB and piriform cortex of KO mice significantly decreased. Although Prune2 mRNA also significantly decreased in the spinal cord, the gross anatomy of the spinal cord and dorsal root ganglion (DRG) was intact. Further, disturbance of the sensory and motor system was not observed in KO mice. Therefore, in the current study, we examined the role of Olfaxin in the olfactory system where PRUNE2, BMCC1, and BNIPXL are scarcely expressed. Odor preference was impaired in KO mice using opposite-sex urinary scents as well as a non-social odor stimulus (almond). Results of the odor-aversion test demonstrated that odor-associative learning was disrupted in KO mice. Moreover, the NMDAR2A/NMDAR2B subunits switch in the piriform cortex was not observed in KO mice. These results indicated that Olfaxin may play a critical role in odor preference and olfactory memory. Copyright © 2018 Elsevier B.V. All rights reserved.

Long-chain fatty acid triglyceride (TG) metabolism disorder impairs male fertility: a study using adipose triglyceride lipase deficient mice.

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Masaki, Hidetake; Kim, Namhyo; Nakamura, Hitomi; Kumasawa, Keiichi; Kamata, Eriko; Hirano, Ken-Ichi; Kimura, Tadashi

2017-07-01

Does the deletion of adipose triglyceride lipase (Atgl) gene impair male fertility? The deletion of Atgl gene impaired male fertility but the effect was partially reversed by a low long-chain triglyceride (TG) diet. ATGL specifically hydrolyses long-chain fatty acid TG to diacylglycerol and a high level of expression of ATGL in testes has been reported. However, the role of ATGL in male fertility is unknown. To investigate the effect of deletion of Atgl gene on male fertility, cauda epididymides and testes were collected from wild-type, heterozygous and homozygous Atgl-deficient mice at 10 weeks of age and epididymal sperm analysis and histological analysis of the testes were performed. To investigate whether a medium-chain triglycerides (MCTs) replacement diet mitigated the impaired male fertility by deletion of Atgl gene, homozygous Atgl-deficient mice were fed a MCT replacement diet, or a standard diet including long-chain triglycerides (LCTs) in a control group, for 6 weeks from 5 weeks of age (n = 22). The systematic and local effects of the MCT replacement diet on spermatogenesis and sperm maturation in the epididymis were analyzed at 10 weeks of age. Hematoxylin and eosin staining in paraffin-embedded sections of testes and Oil Red O staining in frozen sections of testes were performed. The epididymal sperm concentrations were analyzed. Statistical analyses were performed using the Student's t-test or Mann-Whitney U test with Shapiro-Wilk Normality test. Although heterozygous mice were fertile and showed a similar number of epididymal total and motile sperm concentrations to wild-type mice, the deletion of Atgl gene in homozygous mice led to accumulation of TG deposits in testes and impaired spermatogenesis. The deletion of Atgl gene also impaired the sperm maturation process required for sperm to acquire the ability to move forward in the epididymis. The MCT replacement diet for 6 weeks increased the plasma level of non-esterified fatty acid (NEFA) (1

Impaired peripheral nerve regeneration in type-2 diabetic mouse model.

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Pham, Vuong M; Tu, Nguyen Huu; Katano, Tayo; Matsumura, Shinji; Saito, Akira; Yamada, Akihiro; Furue, Hidemasa; Ito, Seiji

2018-01-01

Peripheral neuropathy is one of the most common and serious complications of type-2 diabetes. Diabetic neuropathy is characterized by a distal symmetrical sensorimotor polyneuropathy, and its incidence increases in patients 40 years of age or older. In spite of extensive research over decades, there are few effective treatments for diabetic neuropathy besides glucose control and improved lifestyle. The earliest changes in diabetic neuropathy occur in sensory nerve fibers, with initial degeneration and regeneration resulting in pain. To seek its effective treatment, here we prepared a type-2 diabetic mouse model by giving mice 2 injections of streptozotocin and nicotinamide and examining the ability for nerve regeneration by using a sciatic nerve transection-regeneration model previously established by us. Seventeen weeks after the last injection, the mice exhibited symptoms of type-2 diabetes, that is, impaired glucose tolerance, decreased insulin level, mechanical hyperalgesia, and impaired sensory nerve fibers in the plantar skin. These mice showed delayed functional recovery and nerve regeneration by 2 weeks compared with young healthy mice and by 1 week compared with age-matched non-diabetic mice after axotomy. Furthermore, type-2 diabetic mice displayed increased expression of PTEN in their DRG neurons. Administration of a PTEN inhibitor at the cutting site of the nerve for 4 weeks promoted the axonal transport and functional recovery remarkably. This study demonstrates that peripheral nerve regeneration was impaired in type-2 diabetic model and that its combination with sciatic nerve transection is suitable for the study of the pathogenesis and treatment of early diabetic neuropathy. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Seipin knockout in mice impairs stem cell proliferation and progenitor cell differentiation in the adult hippocampal dentate gyrus via reduced levels of PPARγ

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Guoxi Li

2015-12-01

Full Text Available The seipin gene (BSCL2 was originally identified in humans as a loss-of-function gene associated with congenital generalized lipodystrophy type 2 (CGL2. Neuronal seipin-knockout (seipin-nKO mice display a depression-like phenotype with a reduced level of hippocampal peroxisome proliferator-activated receptor gamma (PPARγ. The present study investigated the influence of seipin deficiency on adult neurogenesis in the hippocampal dentate gyrus (DG and the underlying mechanisms of the effects. We show that the proliferative capability of stem cells in seipin-nKO mice was substantially reduced compared to in wild-type (WT mice, and that this could be rescued by the PPARγ agonist rosiglitazone (rosi. In seipin-nKO mice, neuronal differentiation of progenitor cells was inhibited, with the enhancement of astrogliogenesis; both of these effects were recovered by rosi treatment during early stages of progenitor cell differentiation. In addition, rosi treatment could correct the decline in hippocampal ERK2 phosphorylation and cyclin A mRNA level in seipin-nKO mice. The MEK inhibitor U0126 abolished the rosi-rescued cell proliferation and cyclin A expression in seipin-nKO mice. In seipin-nKO mice, the hippocampal Wnt3 protein level was less than that in WT mice, and there was a reduction of neurogenin 1 (Neurog1 and neurogenic differentiation 1 (NeuroD1 mRNA, levels of which were corrected by rosi treatment. STAT3 phosphorylation (Tyr705 was enhanced in seipin-nKO mice, and was further elevated by rosi treatment. Finally, rosi treatment for 10 days could alleviate the depression-like phenotype in seipin-nKO mice, and this alleviation was blocked by the MEK inhibitor U0126. The results indicate that, by reducing PPARγ, seipin deficiency impairs proliferation and differentiation of neural stem and progenitor cells, respectively, in the adult DG, which might be responsible for the production of the depression-like phenotype in seipin-nKO mice.

Impaired insulin secretion and glucose intolerance in synaptotagmin-7 null mutant mice

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Gustavsson, Natalia; Lao, Ye; Maximov, Anton

2008-01-01

and insulin release. Here, we show that synaptotagmin-7 is required for the maintenance of systemic glucose tolerance and glucose-stimulated insulin secretion. Mutant mice have normal insulin sensitivity, insulin production, islet architecture and ultrastructural organization, and metabolic and calcium...... secretion in pancreatic beta-cells. Of these other synaptotagmins, synaptotagmin-7 is one of the most abundant and is present in pancreatic beta-cells. To determine whether synaptotagmin-7 regulates Ca(2+)-dependent insulin secretion, we analyzed synaptotagmin-7 null mutant mice for glucose tolerance...... responses but exhibit impaired glucose-induced insulin secretion, indicating a calcium-sensing defect during insulin-containing secretory granule exocytosis. Taken together, our findings show that synaptotagmin-7 functions as a positive regulator of insulin secretion and may serve as a calcium sensor...

Mice do not develop conditioned taste aversion because of immunity loss.

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Vidal, Jose

2011-01-01

This study intends to test the generation of conditioned taste aversion and conditioned immunodepression by daily paired administration of saccharin solution with cyclophosphamide, 15 mg/kg, for 4 days. One group of male mice of the outbred CD1 strain drank 0.15% saccharin and received 1 injection of cyclophosphamide, 15 mg/kg, for 4 days (paired group), another group (unpaired group) received the same doses of saccharin and cyclophosphamide noncontingently, the third group (cy60) received saccharin paired with cyclophosphamide, 60 mg/kg, and the fourth group (placebo) received saccharin in the absence of cyclophosphamide. All mice were immunized with keyhole limpet hemocyanin (KLH), 0.2 mg, 1 day before the treatments. Mice of the paired, unpaired and cy60 groups displayed a similarly decreased antibody response to KLH, but mice of the paired group did not develop an aversion to saccharin while mice of the cy60 group did. Besides, repeat presentation of saccharin to mice of the paired group did not alter their antibody response to ovalbumin compared with mice of the unpaired or placebo group. Taste aversion was not elicited in response to impaired immunity and the conditioned stimulus (saccharin) did not impair the antibody response. 2011 S. Karger AG, Basel.

Aqueous Extract of Black Maca (Lepidium meyenii) on Memory Impairment Induced by Ovariectomy in Mice.

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Rubio, Julio; Qiong, Wang; Liu, Xinmin; Jiang, Zhen; Dang, Haixia; Chen, Shi-Lin; Gonzales, Gustavo F

2011-01-01

The present study aims to test two different doses of aqueous extract of black maca on learning and memory in ovariectomized (OVX) mice and their relation with malonalehyde (MDA), acetylcholinesterase (Ache) and monoamine oxidase (MAO) brain levels. Female mice were divided into five groups: (i) naive (control), (ii) sham, (iii) OVX mice and OVX mice treated with (iv) 0.50 g kg(-1) and (v) 2.00 g kg(-1) black maca. Mice were orally treated with distilled water or black maca during 35 days starting 7 days after surgery. Memory and learning were assessed using the water Morris maze (from day 23-27) and the step-down avoidance test (days 34 and 35). At the end of each treatment, mice were sacrificed by decapitation and brains were dissected out for MDA, Ache and MAO determinations. Black maca (0.5 and 2.0 g/kg) increased step-down latency when compared to OVX control mice. Black maca decreased MDA and Ache levels in OVX mice; whereas, no differences were observed in MAO levels. Finally, black maca improved experimental memory impairment induced by ovariectomy, due in part, by its antioxidant and Ache inhibitory activities.

Experimental sepsis impairs humoral memory in mice.

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Christian Pötschke

Full Text Available Patients with sepsis are often immune suppressed, and experimental mouse models of sepsis also display this feature. However, acute sepsis in mice is also characterized by a generalized B cell activation and plasma cell differentiation, resulting in a marked increase in serum antibody concentration. Its effects on humoral memory are not clearly defined. We measured the effects of experimental sepsis on long-term immunological memory for a defined antigen: we induced colon ascendens stent peritonitis (CASP 8 weeks after 2 rounds of immunization with ovalbumin. Four weeks later, the antigen-specific bone marrow plasma cell count had doubled in immunized non-septic animals, but remained unchanged in immunized septic animals. Sepsis also caused a decrease in antigen-specific serum antibody concentration. We conclude that sepsis weakens humoral memory by impeding the antigen-specific plasma cell pool's development, which is not complete 8 weeks after secondary immunization.

Loss of hfe function reverses impaired recognition memory caused by olfactory manganese exposure in mice.

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Ye, Qi; Kim, Jonghan

2015-03-01

Excessive manganese (Mn) in the brain promotes a variety of abnormal behaviors, including memory deficits, decreased motor skills and psychotic behavior resembling Parkinson's disease. Hereditary hemochromatosis (HH) is a prevalent genetic iron overload disorder worldwide. Dysfunction in HFE gene is the major cause of HH. Our previous study has demonstrated that olfactory Mn uptake is altered by HFE deficiency, suggesting that loss of HFE function could alter manganese-associated neurotoxicity. To test this hypothesis, Hfe-knockout (Hfe (-/-)) and wild-type (Hfe (+/+)) mice mice were intranasally-instilled with manganese chloride (MnCl2 5 mg/kg) or water daily for 3 weeks and examined for memory function. Olfactory Mn diminished both short-term recognition and spatial memory in Hfe (+/+) mice, as examined by novel object recognition task and Barnes maze test, respectively. Interestingly, Hfe (-/-) mice did not show impaired recognition memory caused by Mn exposure, suggesting a potential protective effect of Hfe deficiency against Mn-induced memory deficits. Since many of the neurotoxic effects of manganese are thought to result from increased oxidative stress, we quantified activities of anti-oxidant enzymes in the prefrontal cortex (PFC). Mn instillation decreased superoxide dismutase 1 (SOD1) activity in Hfe (+/+) mice, but not in Hfe (-/-) mice. In addition, Hfe deficiency up-regulated SOD1 and glutathione peroxidase activities. These results suggest a beneficial role of Hfe deficiency in attenuating Mn-induced oxidative stress in the PFC. Furthermore, Mn exposure reduced nicotinic acetylcholine receptor levels in the PFC, indicating that blunted acetylcholine signaling could contribute to impaired memory associated with intranasal manganese. Together, our model suggests that disrupted cholinergic system in the brain is involved in airborne Mn-induced memory deficits and loss of HFE function could in part prevent memory loss via a potential up-regulation of

Increased plasma citrulline in mice marks diet-induced obesity and may predict the development of the metabolic syndrome.

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Manuela Sailer

Full Text Available In humans, plasma amino acid concentrations of branched-chain amino acids (BCAA and aromatic amino acids (AAA increase in states of obesity, insulin resistance and diabetes. We here assessed whether these putative biomarkers can also be identified in two different obesity and diabetic mouse models. C57BL/6 mice with diet-induced obesity (DIO mimic the metabolic impairments of obesity in humans characterized by hyperglycemia, hyperinsulinemia and hepatic triglyceride accumulation. Mice treated with streptozotocin (STZ to induce insulin deficiency were used as a type 1 diabetes model. Plasma amino acid profiling of two high fat (HF feeding trials revealed that citrulline and ornithine concentrations are elevated in obese mice, while systemic arginine bioavailability (ratio of plasma arginine to ornithine + citrulline is reduced. In skeletal muscle, HF feeding induced a reduction of arginine levels while citrulline levels were elevated. However, arginine or citrulline remained unchanged in their key metabolic organs, intestine and kidney. Moreover, the intestinal conversion of labeled arginine to ornithine and citrulline in vitro remained unaffected by HF feeding excluding the intestine as prime site of these alterations. In liver, citrulline is mainly derived from ornithine in the urea cycle and DIO mice displayed reduced hepatic ornithine levels. Since both amino acids share an antiport mechanism for mitochondrial import and export, elevated plasma citrulline may indicate impaired hepatic amino acid handling in DIO mice. In the insulin deficient mice, plasma citrulline and ornithine levels also increased and additionally these animals displayed elevated BCAA and AAA levels like insulin resistant and diabetic patients. Therefore, type 1 diabetic mice but not DIO mice show the "diabetic fingerprint" of plasma amino acid changes observed in humans. Additionally, citrulline may serve as an early indicator of the obesity-dependent metabolic

Deletion of the GluA1 AMPA receptor subunit impairs recency-dependent object recognition memory

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Sanderson, David J.; Hindley, Emma; Smeaton, Emily; Denny, Nick; Taylor, Amy; Barkus, Chris; Sprengel, Rolf; Seeburg, Peter H.; Bannerman, David M.

2011-01-01

Deletion of the GluA1 AMPA receptor subunit impairs short-term spatial recognition memory. It has been suggested that short-term recognition depends upon memory caused by the recent presentation of a stimulus that is independent of contextual–retrieval processes. The aim of the present set of experiments was to test whether the role of GluA1 extends to nonspatial recognition memory. Wild-type and GluA1 knockout mice were tested on the standard object recognition task and a context-independent recognition task that required recency-dependent memory. In a first set of experiments it was found that GluA1 deletion failed to impair performance on either of the object recognition or recency-dependent tasks. However, GluA1 knockout mice displayed increased levels of exploration of the objects in both the sample and test phases compared to controls. In contrast, when the time that GluA1 knockout mice spent exploring the objects was yoked to control mice during the sample phase, it was found that GluA1 deletion now impaired performance on both the object recognition and the recency-dependent tasks. GluA1 deletion failed to impair performance on a context-dependent recognition task regardless of whether object exposure in knockout mice was yoked to controls or not. These results demonstrate that GluA1 is necessary for nonspatial as well as spatial recognition memory and plays an important role in recency-dependent memory processes. PMID:21378100

Bisphenol A impairs the memory function and glutamatergic homeostasis in a sex-dependent manner in mice: Beneficial effects of diphenyl diselenide.

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Jardim, Natália S; Sartori, Glaúbia; Sari, Marcel H M; Müller, Sabrina G; Nogueira, Cristina W

2017-08-15

Bisphenol A (BPA) is a compound integrated in commodities, which consequently increases the human exposure to this toxicant. The deleterious effects of BPA exposure during periods of brain development have been documented mainly concerning the impairment in memory functions. Diphenyl diselenide (PhSe) 2 , an organoselenium compound, shows protective/restorative effects against memory deficits in experimental models. Thus, this study investigated the effects of (PhSe) 2 on the memory impairments induced by BPA exposure to male and female mice and the possible involvement of glutamatergic system in these effects. Three-week-old male and female Swiss mice received BPA (5mg/kg), intragastrically, from 21st to 60th postnatal day. After, the animals were intragastrically treated with (PhSe) 2 (1mg/kg) during seven days. The mice performed the behavioral memory tests and the [ 3 H] glutamate uptake and NMDA receptor subunits (2A and 2B) analyses were carried out in the hippocampus and cerebral cortex of mice. The results demonstrated that the BPA exposure induced impairment of object recognition memory in both sexes. However, it caused impairments in spatial memory in female and in the passive avoidance memory in male mice. Besides, BPA caused a decrease in the [ 3 H] glutamate uptake and NMDA receptor subunit levels in the cortical and hippocampal regions depending on the sex. Treatment with (PhSe) 2 reversed in a sex-independent manner the behavioral impairments and molecular alterations. In conclusion, BPA had a negative effect in different memory types as well as in the glutamatergic parameters in a sex-dependent manner and (PhSe) 2 treatment was effective against these alterations. Copyright © 2017 Elsevier Inc. All rights reserved.

Object recognition impairment in Fmr1 knockout mice is reversed by amphetamine: involvement of dopamine in the medial prefrontal cortex.

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Ventura, R; Pascucci, T; Catania, M V; Musumeci, S A; Puglisi-Allegra, S

2004-09-01

Fragile X syndrome is an X-linked form of mental retardation including, among others, symptoms such as stereotypic behaviour, hyperactivity, hyperarousal, and cognitive deficits. We hypothesized that hyperactivity and/or compromised attentional, cognitive functions may lead to impaired performance in cognitive tasks in Fmr1 knockout mice, the most widely used animal model of fragile X syndrome, and suggested that psychostimulant treatment may improve performance by acting on one or both components. Since hyperactivity and cognitive functions have been suggested to depend on striatal and prefrontal cortex dopaminergic dysfunction, we assessed whether amphetamine produced beneficial, positive effects by acting on dopaminergic corticostriatal systems. Our results show that Fmr1 knockout mice are not able to discriminate between a familiar object and a novel one in the object recognition test, thus showing a clear-cut cognitive impairment that, to date, has been difficult to demonstrate in other cognitive tasks. Amphetamine improved performance of Fmr1 knockout mice, leading to enhanced ability to discriminate novel versus familiar objects, without significantly affecting locomotor activity. In agreement with behavioural data, amphetamine produced a greater increase in dopamine release in the prefrontal cortex of Fmr1 knockout compared with the wild-type mice, while a weak striatal dopaminergic response was observed in Fmr1 knockout mice. Our data support the view that the psychostimulant ameliorates performance in Fmr1 knockout mice by improving merely cognitive functions through its action on prefrontal cortical dopamine, irrespective of its action on motor hyperactivity. These results indicate that prefrontal cortical dopamine plays a major role in cognitive impairments characterizing Fmr1 knockout mice, thus pointing to an important aetiological factor in the fragile X syndrome.

ApoB100/LDLR-/- hypercholesterolaemic mice as a model for mild cognitive impairment and neuronal damage.

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Carlos Ramírez

Full Text Available Recent clinical findings support the notion that the progressive deterioration of cholesterol homeostasis is a central player in Alzheimer's disease (AD. Epidemiological studies suggest that high midlife plasma total cholesterol levels are associated with an increased risk of AD. This paper reports the plasma cholesterol concentrations, cognitive performance, locomotor activity and neuropathological signs in a murine model (transgenic mice expressing apoB100 but knockout for the LDL receptor [LDLR] of human familial hypercholesterolaemia (FH. From birth, these animals have markedly elevated LDL-cholesterol and apolipoprotein B100 (apoB100 levels. These transgenic mice were confirmed to have higher plasma cholesterol concentrations than wild-type mice, an effect potentiated by aging. Further, 3-month-old transgenic mice showed cholesterol (total and fractions concentrations considerably higher than those of 18-month-old wild-type mice. The hypercholesterolaemia of the transgenic mice was associated with a clear locomotor deficit (as determined by rotarod, grip strength and open field testing and impairment of the episodic-like memory (determined by the integrated memory test. This decline in locomotor activity and cognitive status was associated with neuritic dystrophy and/or the disorganization of the neuronal microtubule network, plus an increase in astrogliosis and lipid peroxidation in the brain regions associated with AD, such as the motor and lateral entorhinal cortex, the amygdaloid basal nucleus, and the hippocampus. Aortic atherosclerotic lesions were positively correlated with age, although potentiated by the transgenic genotype, while cerebral β-amyloidosis was positively correlated with genetic background rather than with age. These findings confirm hypercholesterolaemia as a key biomarker for monitoring mild cognitive impairment, and shows these transgenic mice can be used as a model for cognitive and psycho-motor decline.

Bisphenol A impairs hepatic glucose sensing in C57BL/6 male mice.

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Leigh Perreault

Full Text Available AIMS/HYPOTHESIS: Glucose sensing (eg. glucokinase activity becomes impaired in the development of type 2 diabetes, the etiology of which is unclear. Estrogen can stimulate glucokinase activity, whereas the pervasive environmental pollutant bisphenol A (BPA can inhibit estrogen action, hence we aimed to determine the effect of BPA on glucokinase activity directly. METHODS: To evaluate a potential acute effect on hepatic glucokinase activity, BPA in water (n = 5 vs. water alone (n = 5 was administered at the EPA's purported "safe dose" (50 µg/kg by gavage to lean 6-month old male C57BL/6 mice. Two hours later, animals were euthanized and hepatic glucokinase activity measured over glucose levels from 1-20 mmol/l in liver homogenate. To determine the effect of chronic BPA exposure on hepatic glucokinase activity, lean 6-month old male C57BL/6 mice were provided with water (n = 15 or water with 1.75 mM BPA (∼50 µg/kg/day; n = 14 for 2 weeks. Following the 2-week exposure, animals were euthanized and glucokinase activity measured as above. RESULTS: Hepatic glucokinase activity was signficantly suppressed after 2 hours in animals given an oral BPA bolus compared to those who received only water (p = 0.002-0.029 at glucose 5-20 mmol/l; overall treatment effect p<0.001. Exposure to BPA over 2 weeks also suppressed hepatic glucokinase activity in exposed vs. unexposed mice (overall treatment effect, p = 0.003. In both experiments, the Hill coefficient was higher and Vmax lower in mice treated with BPA. CONCLUSIONS/INTERPRETATION: Both acute and chronic exposure to BPA significantly impair hepatic glucokinase activity and function. These findings identify a potential mechanism for how BPA may increase risk for diabetes.

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

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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.

Postpartum estrogen withdrawal impairs hippocampal neurogenesis and causes depression- and anxiety-like behaviors in mice.

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Zhang, Zhuan; Hong, Juan; Zhang, Suyun; Zhang, Tingting; Sha, Sha; Yang, Rong; Qian, Yanning; Chen, Ling

2016-04-01

Postpartum estrogen withdrawal is known to be a particularly vulnerable time for depressive symptoms. Ovariectomized adult mice (OVX-mice) treated with hormone-simulated pregnancy (HSP mice) followed by a subsequent estradiol benzoate (EB) withdrawal (EW mice) exhibited depression- and anxiety-like behaviors, as assessed by forced swim, tail suspension and elevated plus-maze, while HSP mice, OVX mice or EB-treated OVX mice (OVX/EB mice) did not. The survival and neurite growth of newborn neurons in hippocampal dentate gyrus were examined on day 5 after EW. Compared with controls, the numbers of 28-day-old BrdU(+) and BrdU(+)/NeuN(+) cells were increased in HSP mice but significantly decreased in EW mice; the numbers of 10-day-old BrdU(+) cells were increased in HSP mice and OVX/EB mice; and the density of DCX(+) fibers was reduced in EW mice and OVX mice. The phosphorylation of hippocampal NMDA receptor (NMDAr) NR2B subunit or Src was increased in HSP mice but decreased in EW mice. NMDAr agonist NMDA prevented the loss of 28-day-old BrdU(+) cells and the depression- and anxiety-like behaviors in EW mice. NR2B inhibitor Ro25-6981 or Src inhibitor dasatinib caused depression- and anxiety-like behaviors in HSP mice with the reduction of 28-day-old BrdU(+) cells. The hippocampal BDNF levels were reduced in EW mice and OVX mice. TrkB receptor inhibitor K252a reduced the density of DCX(+) fibers in HSP mice without the reduction of 28-day-old BrdU(+) cells, or the production of affective disorder. Collectively, these results indicate that postpartum estrogen withdrawal impairs hippocampal neurogenesis in mice that show depression- and anxiety-like behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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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.

Absence of Carbohydrate Response Element Binding Protein in Adipocytes Causes Systemic Insulin Resistance and Impairs Glucose Transport

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Archana Vijayakumar

2017-10-01

Full Text Available Lower adipose-ChREBP and de novo lipogenesis (DNL are associated with insulin resistance in humans. Here, we generated adipose-specific ChREBP knockout (AdChREBP KO mice with negligible sucrose-induced DNL in adipose tissue (AT. Chow-fed AdChREBP KO mice are insulin resistant with impaired insulin action in the liver, muscle, and AT and increased AT inflammation. HFD-fed AdChREBP KO mice are also more insulin resistant than controls. Surprisingly, adipocytes lacking ChREBP display a cell-autonomous reduction in insulin-stimulated glucose transport that is mediated by impaired Glut4 translocation and exocytosis, not lower Glut4 levels. AdChREBP KO mice have lower levels of palmitic acid esters of hydroxy stearic acids (PAHSAs in serum, and AT. 9-PAHSA supplementation completely rescues their insulin resistance and AT inflammation. 9-PAHSA also normalizes impaired glucose transport and Glut4 exocytosis in ChREBP KO adipocytes. Thus, loss of adipose-ChREBP is sufficient to cause insulin resistance, potentially by regulating AT glucose transport and flux through specific lipogenic pathways.

Aqueous Extract of Black Maca (Lepidium meyenii on Memory Impairment Induced by Ovariectomy in Mice

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Julio Rubio

2011-01-01

Full Text Available The present study aims to test two different doses of aqueous extract of black maca on learning and memory in ovariectomized (OVX mice and their relation with malonalehyde (MDA, acetylcholinesterase (Ache and monoamine oxidase (MAO brain levels. Female mice were divided into five groups: (i naive (control, (ii sham, (iii OVX mice and OVX mice treated with (iv 0.50 g kg−1 and (v 2.00 g kg−1 black maca. Mice were orally treated with distilled water or black maca during 35 days starting 7 days after surgery. Memory and learning were assessed using the water Morris maze (from day 23–27 and the step-down avoidance test (days 34 and 35. At the end of each treatment, mice were sacrificed by decapitation and brains were dissected out for MDA, Ache and MAO determinations. Black maca (0.5 and 2.0 g/kg increased step-down latency when compared to OVX control mice. Black maca decreased MDA and Ache levels in OVX mice; whereas, no differences were observed in MAO levels. Finally, black maca improved experimental memory impairment induced by ovariectomy, due in part, by its antioxidant and Ache inhibitory activities.

Reduced spatial learning in mice infected with the nematode, Heligmosomoides polygyrus.

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Kavaliers, M; Colwell, D D

1995-06-01

Parasite modification of host behaviour influences a number of critical responses, but little is known about the effects on host spatial abilities. This study examined the effects of infection with the intestinal trichostrongylid nematode, Heligmosomoides polygyrus, on spatial water maze learning by male laboratory mice, Mus musculus. In this task individual mice had to learn the spatial location of a submerged hidden platform using extramaze visual cues. Determinations of spatial performance were made on day 19 post-infection with mice that had been administered either 50 or 200 infective larvae of H. polygyrus. The infected mice displayed over 1 day of testing (6 blocks of 4 trials) significantly poorer acquisition and retention of the water maze task than either sham-infected or control mice, with mice that had received 200 infective larvae displaying significantly poorer spatial performance than individuals receiving 50 larvae. The decrease in spatial learning occurred in the absence of either any symptoms of illness and malaise, or any evident motor, visual and motivational impairments. It is suggested that in this single host system the parasitic infection-induced decrease in spatial learning arises as a side-effect of the host's immunological and neuromodulatory responses and represents a fitness cost of response to infection.

Dysfunction of the RAR/RXR signaling pathway in the forebrain impairs hippocampal memory and synaptic plasticity

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Nomoto Masanori

2012-02-01

Full Text Available Abstract Background Retinoid signaling pathways mediated by retinoic acid receptor (RAR/retinoid × receptor (RXR-mediated transcription play critical roles in hippocampal synaptic plasticity. Furthermore, recent studies have shown that treatment with retinoic acid alleviates age-related deficits in hippocampal long-term potentiation (LTP and memory performance and, furthermore, memory deficits in a transgenic mouse model of Alzheimer's disease. However, the roles of the RAR/RXR signaling pathway in learning and memory at the behavioral level have still not been well characterized in the adult brain. We here show essential roles for RAR/RXR in hippocampus-dependent learning and memory. In the current study, we generated transgenic mice in which the expression of dominant-negative RAR (dnRAR could be induced in the mature brain using a tetracycline-dependent transcription factor and examined the effects of RAR/RXR loss. Results The expression of dnRAR in the forebrain down-regulated the expression of RARβ, a target gene of RAR/RXR, indicating that dnRAR mice exhibit dysfunction of the RAR/RXR signaling pathway. Similar with previous findings, dnRAR mice displayed impaired LTP and AMPA-mediated synaptic transmission in the hippocampus. More importantly, these mutant mice displayed impaired hippocampus-dependent social recognition and spatial memory. However, these deficits of LTP and memory performance were rescued by stronger conditioning stimulation and spaced training, respectively. Finally, we found that pharmacological blockade of RARα in the hippocampus impairs social recognition memory. Conclusions From these observations, we concluded that the RAR/RXR signaling pathway greatly contributes to learning and memory, and LTP in the hippocampus in the adult brain.

Hard-Diet Feeding Recovers Neurogenesis in the Subventricular Zone and Olfactory Functions of Mice Impaired by Soft-Diet Feeding

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Utsugi, Chizuru; Miyazono, Sadaharu; Osada, Kazumi; Sasajima, Hitoshi; Noguchi, Tomohiro; Matsuda, Mitsuyoshi; Kashiwayanagi, Makoto

2014-01-01

The subventricular zone (SVZ) generates an immense number of neurons even during adulthood. These neurons migrate to the olfactory bulb (OB) and differentiate into granule cells and periglomerular cells. The information broadcast by general odorants is received by the olfactory sensory neurons and transmitted to the OB. Recent studies have shown that a reduction of mastication impairs both neurogenesis in the hippocampus and brain functions. To examine these effects, we first measured the difference in Fos-immunoreactivity (Fos-ir) at the principal sensory trigeminal nucleus (Pr5), which receives intraoral touch information via the trigeminal nerve, when female adult mice ingested a hard or soft diet to explore whether soft-diet feeding could mimic impaired mastication. Ingestion of a hard diet induced greater expression of Fos-ir cells at the Pr5 than did a soft diet or no diet. Bromodeoxyuridine-immunoreactive (BrdU-ir) structures in sagittal sections of the SVZ and in the OB of mice fed a soft or hard diet were studied to explore the effects of changes in mastication on newly generated neurons. After 1 month, the density of BrdU-ir cells in the SVZ and OB was lower in the soft-diet-fed mice than in the hard-diet-fed mice. The odor preferences of individual female mice to butyric acid were tested in a Y-maze apparatus. Avoidance of butyric acid was reduced by the soft-diet feeding. We then explored the effects of the hard-diet feeding on olfactory functions and neurogenesis in the SVZ of mice impaired by soft-diet feeding. At 3 months of hard-diet feeding, avoidance of butyric acid was reversed and responses to odors and neurogenesis were recovered in the SVZ. The present results suggest that feeding with a hard diet improves neurogenesis in the SVZ, which in turn enhances olfactory function at the OB. PMID:24817277

Augmented hepatic injury followed by impaired regeneration in metallothionein-I/II knockout mice after treatment with thioacetamide

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Oliver, Jordan R.; Jiang, Sean; Cherian, M. George

2006-01-01

A previous study (Oliver, J.R., Mara, T.W., Cherian, M.G. 2005. Impaired hepatic regeneration in metallothionein-I/II knockout mice after partial hepatectomy. Exp. Biol. Med. 230, 61-67) has shown an impairment of liver regeneration following partial hepatectomy (PH) in metallothionein (MT)-I and MT-II gene knockout (MT-null) mice, thus suggesting a requirement for MT in cellular growth. The present study was undertaken to investigate whether MT may play a similar role in hepatic injury and regeneration after acute treatment with thioacetamide (TAA). Hepatotoxicity of TAA is caused by the generation of oxidative stress. TAA was injected ip to both wild-type (WT) and MT-null mice. Mice were killed at 6, 12, 24, 48, 60, and 72 h after injection of TAA (125 mg/kg) or 48 h after injection of saline (vehicle control), and different parameters of hepatic injury were measured. The levels of hepatic lipid peroxidation were increased at 12 h in both types of mice; however, lipid peroxidation was significantly less in WT mice than MT-null mice at 48 h after injection of TAA. Analysis of hepatic glutathione (GSH) levels after TAA injection showed depletion of GSH at 12 h in WT mice and at 6 h in MT-null mice; however, significantly more GSH was depleted early (6-24 h) in MT-null mice than WT mice. An increase in hepatic iron (Fe) levels was observed in both types of mice after injection of TAA, but Fe levels were significantly higher in MT-null mice than WT mice at 6-60 h. The levels of hepatic copper (Cu) and zinc (Zn) were significantly higher in WT mice than MT-null mice at 6-60 h for Cu, and at 24 h and 60 h for Zn, respectively. Histopathological examination showed hemorrhagic necrosis in the liver of both types of mice at 12-72 h, with hepatic injury being more prominent in MT-null mice than WT mice. The hepatic MT levels were increased in WT mice after injection of TAA, and were highest at 24-72 h. Immunohistochemical staining for MT in WT mice indicated the presence

Aged Tg2576 mice are impaired on social memory and open field habituation tests.

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Deacon, R M J; Koros, E; Bornemann, K D; Rawlins, J N P

2009-02-11

In a previous publication [Deacon RMJ, Cholerton LL, Talbot K, Nair-Roberts RG, Sanderson DJ, Romberg C, et al. Age-dependent and -independent behavioral deficits in Tg2576 mice. Behav Brain Res 2008;189:126-38] we found that very few cognitive tests were suitable for demonstrating deficits in Tg2576 mice, an amyloid over-expression model of Alzheimer's disease, even at 23 months of age. However, in a retrospective analysis of a separate project on these mice, tests of social memory and open field habituation revealed large cognitive impairments. Controls showed good open field habituation, but Tg2576 mice were hyperactive and failed to habituate. In the test of social memory for a juvenile mouse, controls showed considerably less social investigation on the second meeting, indicating memory of the juvenile, whereas Tg2576 mice did not show this decrement.As a control for olfactory sensitivity, on which social memory relies, the ability to find a food pellet hidden under wood chip bedding was assessed. Tg2576 mice found the pellet as quickly as controls. As this test requires digging ability, this was independently assessed in tests of burrowing and directly observed digging. In line with previous results and the hippocampal dysfunction characteristic of aged Tg2576 mice, they both burrowed and dug less than controls.

Short-term long chain omega3 diet protects from neuroinflammatory processes and memory impairment in aged mice.

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Virginie F Labrousse

Full Text Available Regular consumption of food enriched in omega3 polyunsaturated fatty acids (ω3 PUFAs has been shown to reduce risk of cognitive decline in elderly, and possibly development of Alzheimer's disease. Docosahexaenoic acid (DHA and eicosapentaenoic acid (EPA are the most likely active components of ω3-rich PUFAs diets in the brain. We therefore hypothesized that exposing mice to a DHA and EPA enriched diet may reduce neuroinflammation and protect against memory impairment in aged mice. For this purpose, mice were exposed to a control diet throughout life and were further submitted to a diet enriched in EPA and DHA during 2 additional months. Cytokine expression together with a thorough analysis of astrocytes morphology assessed by a 3D reconstruction was measured in the hippocampus of young (3-month-old and aged (22-month-old mice. In addition, the effects of EPA and DHA on spatial memory and associated Fos activation in the hippocampus were assessed. We showed that a 2-month EPA/DHA treatment increased these long-chain ω3 PUFAs in the brain, prevented cytokines expression and astrocytes morphology changes in the hippocampus and restored spatial memory deficits and Fos-associated activation in the hippocampus of aged mice. Collectively, these data indicated that diet-induced accumulation of EPA and DHA in the brain protects against neuroinflammation and cognitive impairment linked to aging, further reinforcing the idea that increased EPA and DHA intake may provide protection to the brain of aged subjects.

Low empathy-like behaviour in male mice associates with impaired sociability, emotional memory, physiological stress reactivity and variations in neurobiological regulations.

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Laviola, Giovanni; Zoratto, Francesca; Ingiosi, Danilo; Carito, Valentina; Huzard, Damien; Fiore, Marco; Macrì, Simone

2017-01-01

Deficits in empathy have been proposed to constitute a hallmark of several psychiatric disturbances like conduct disorder, antisocial and narcissistic personality disorders. Limited sensitivity to punishment, shallow or deficient affect and reduced physiological reactivity to environmental stressors have been often reported to co-occur with limited empathy and contribute to the onset of antisocial phenotypes. Empathy in its simplest form (i.e. emotional contagion) is addressed in preclinical models through the evaluation of the social transmission of emotional states: mice exposed to a painful stimulus display a higher response if in the presence of a familiar individual experiencing a higher degree of discomfort, than in isolation. In the present study, we investigated whether a reduction of emotional contagion can be considered a predictor of reduced sociality, sensitivity to punishment and physiological stress reactivity. To this aim, we first evaluated emotional contagion in a group of Balb/cJ mice and then discretised their values in four quartiles. The upper (i.e. Emotional Contagion Prone, ECP) and the lower (i.e. Emotional Contagion Resistant, ECR) quartiles constituted the experimental groups. Our results indicate that mice in the lower quartile are characterized by reduced sociability, impaired memory of negative events and dampened hypothalamic-pituitary-adrenocortical reactivity to external stressors. Furthermore, in the absence of changes in oxytocin receptor density, we show that these mice exhibit elevated concentrations of oxytocin and vasopressin and reduced density of BDNF receptors in behaviourally-relevant brain areas. Thus, not only do present results translate to the preclinical investigation of psychiatric disturbances, but also they can contribute to the study of emotional contagion in terms of its adaptive significance.

Low empathy-like behaviour in male mice associates with impaired sociability, emotional memory, physiological stress reactivity and variations in neurobiological regulations.

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Giovanni Laviola

Full Text Available Deficits in empathy have been proposed to constitute a hallmark of several psychiatric disturbances like conduct disorder, antisocial and narcissistic personality disorders. Limited sensitivity to punishment, shallow or deficient affect and reduced physiological reactivity to environmental stressors have been often reported to co-occur with limited empathy and contribute to the onset of antisocial phenotypes. Empathy in its simplest form (i.e. emotional contagion is addressed in preclinical models through the evaluation of the social transmission of emotional states: mice exposed to a painful stimulus display a higher response if in the presence of a familiar individual experiencing a higher degree of discomfort, than in isolation. In the present study, we investigated whether a reduction of emotional contagion can be considered a predictor of reduced sociality, sensitivity to punishment and physiological stress reactivity. To this aim, we first evaluated emotional contagion in a group of Balb/cJ mice and then discretised their values in four quartiles. The upper (i.e. Emotional Contagion Prone, ECP and the lower (i.e. Emotional Contagion Resistant, ECR quartiles constituted the experimental groups. Our results indicate that mice in the lower quartile are characterized by reduced sociability, impaired memory of negative events and dampened hypothalamic-pituitary-adrenocortical reactivity to external stressors. Furthermore, in the absence of changes in oxytocin receptor density, we show that these mice exhibit elevated concentrations of oxytocin and vasopressin and reduced density of BDNF receptors in behaviourally-relevant brain areas. Thus, not only do present results translate to the preclinical investigation of psychiatric disturbances, but also they can contribute to the study of emotional contagion in terms of its adaptive significance.

Collagen VI Null Mice as a Model for Early Onset Muscle Decline in Aging

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Daniele Capitanio

2017-10-01

Full Text Available Collagen VI is an extracellular matrix (ECM protein playing a key role in skeletal muscles and whose deficiency leads to connective tissue diseases in humans and in animal models. However, most studies have been focused on skeletal muscle features. We performed an extensive proteomic profiling in two skeletal muscles (diaphragm and gastrocnemius of wild-type and collagen VI null (Col6a1−/− mice at different ages, from 6- (adult to 12- (aged month-old to 24 (old month-old. While in wild-type animals the number of proteins and the level of modification occurring during aging were comparable in the two analyzed muscles, Col6a1−/− mice displayed a number of muscle-type specific variations. In particular, gastrocnemius displayed a limited number of dysregulated proteins in adult mice, while in aged muscles the modifications were more pronounced in terms of number and level. In diaphragm, the differences displayed by 6-month-old Col6a1−/− mice were more pronounced compared to wild-type mice and persisted at 12 months of age. In adult Col6a1−/− mice, the major variations were found in the enzymes belonging to the glycolytic pathway and the tricarboxylic acid (TCA cycle, as well as in autophagy-related proteins. When compared to wild-type animals Col6a1−/− mice displayed a general metabolic rewiring which was particularly prominent the diaphragm at 6 months of age. Comparison of the proteomic features and the molecular analysis of metabolic and autophagic pathways in adult and aged Col6a1−/− diaphragm indicated that the effects of aging, culminating in lipotoxicity and autophagic impairment, were already present at 6 months of age. Conversely, the effects of aging in Col6a1−/− gastrocnemius were similar but delayed becoming apparent at 12 months of age. A similar metabolic rewiring and autophagic impairment was found in the diaphragm of 24-month-old wild-type mice, confirming that fatty acid synthase (FASN increment and

Adenovirus vector expressing keratinocyte growth factor using CAG promoter impairs pulmonary function of mice with elastase-induced emphysema.

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Oki, Hiroshi; Yazawa, Takuya; Baba, Yasuko; Kanegae, Yumi; Sato, Hanako; Sakamoto, Seiko; Goto, Takahisa; Saito, Izumu; Kurahashi, Kiyoyasu

2017-07-01

Pulmonary emphysema impairs quality of life and increases mortality. It has previously been shown that administration of adenovirus vector expressing murine keratinocyte growth factor (KGF) before elastase instillation prevents pulmonary emphysema in mice. We therefore hypothesized that therapeutic administration of KGF would restore damage to lungs caused by elastase instillation and thus improve pulmonary function in an animal model. KGF expressing adenovirus vector, which prevented bleomycin-induced pulmonary fibrosis in a previous study, was constructed. Adenovirus vector (1.0 × 10 9 plaque-forming units) was administered intratracheally one week after administration of elastase into mouse lungs. One week after administration of KGF-vector, exercise tolerance testing and blood gas analysis were performed, after which the lungs were removed under deep anesthesia. KGF-positive pneumocytes were more numerous, surfactant protein secretion in the airspace greater and mean linear intercept of lungs shorter in animals that had received KGF than in control animals. Unexpectedly, however, arterial blood oxygenation was worse in the KGF group and maximum running speed, an indicator of exercise capacity, had not improved after KGF in mice with elastase-induced emphysema, indicating that KGF-expressing adenovirus vector impaired pulmonary function in these mice. Notably, vector lacking KGF-expression unit did not induce such impairment, implying that the KGF expression unit itself may cause the damage to alveolar cells. Possible involvement of the CAG promoter used for KGF expression in impairing pulmonary function is discussed. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

Comprehensive Behavioral Analysis of Activating Transcription Factor 5-Deficient Mice

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Mariko Umemura

2017-07-01

Full Text Available Activating transcription factor 5 (ATF5 is a member of the CREB/ATF family of basic leucine zipper transcription factors. We previously reported that ATF5-deficient (ATF5-/- mice demonstrated abnormal olfactory bulb development due to impaired interneuron supply. Furthermore, ATF5-/- mice were less aggressive than ATF5+/+ mice. Although ATF5 is widely expressed in the brain, and involved in the regulation of proliferation and development of neurons, the physiological role of ATF5 in the higher brain remains unknown. Our objective was to investigate the physiological role of ATF5 in the higher brain. We performed a comprehensive behavioral analysis using ATF5-/- mice and wild type littermates. ATF5-/- mice exhibited abnormal locomotor activity in the open field test. They also exhibited abnormal anxiety-like behavior in the light/dark transition test and open field test. Furthermore, ATF5-/- mice displayed reduced social interaction in the Crawley’s social interaction test and increased pain sensitivity in the hot plate test compared with wild type. Finally, behavioral flexibility was reduced in the T-maze test in ATF5-/- mice compared with wild type. In addition, we demonstrated that ATF5-/- mice display disturbances of monoamine neurotransmitter levels in several brain regions. These results indicate that ATF5 deficiency elicits abnormal behaviors and the disturbance of monoamine neurotransmitter levels in the brain. The behavioral abnormalities of ATF5-/- mice may be due to the disturbance of monoamine levels. Taken together, these findings suggest that ATF5-/- mice may be a unique animal model of some psychiatric disorders.

Isorhynchophylline improves learning and memory impairments induced by D-galactose in mice.

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Xian, Yan-Fang; Su, Zi-Ren; Chen, Jian-Nan; Lai, Xiao-Ping; Mao, Qing-Qiu; Cheng, Christopher H K; Ip, Siu-Po; Lin, Zhi-Xiu

2014-10-01

Isorhynchophylline (IRN), an alkaloid isolated from Uncaria rhynchophylla, has been reported to improve cognitive impairment induced by beta-amyloid in rats. However, whether IRN could also ameliorate the D-galactose (D-gal)-induced mouse memory deficits is still not clear. In the present study, we aimed to investigate whether IRN had potential protective effect against the D-gal-induced cognitive deficits in mice. Mice were given a subcutaneous injection of D-gal (100mg/kg) and orally administered IRN (20 or 40mg/kg) daily for 8weeks, followed by assessing spatial learning and memory function by the Morris water maze test. The results showed that IRN significantly improved spatial learning and memory function in the D-gal-treated mice. In the mechanistic studies, IRN significantly increased the level of glutathione (GSH) and the activities of superoxide dismutase (SOD) and catalase (CAT), while decreased the level of malondialdehyde (MDA) in the brain tissues of the D-gal-treated mice. Moreover, IRN (20 or 40mg/kg) significantly inhibited the production of prostaglandin E 2 (PGE2) and nitric oxide (NO), and the mRNA expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), as well as the activation of nuclear factor kappa B (NF-κB) in the brain tissues of D-gal-treated mice. Our results amply demonstrated that IRN was able to ameliorate cognitive deficits induced by D-gal in mice, and the observed cognition-improving action may be mediated, at least in part, through enhancing the antioxidant status and anti-inflammatory effect of brain tissues via NFκB signaling. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impaired c-Fos and polo-like kinase 2 induction in the limbic system of fear-conditioned α-synuclein transgenic mice.

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Heinrich Schell

Full Text Available α-Synuclein (αSYN is genetically and neuropathologically linked to a spectrum of neurodegenerative diseases including Parkinson's disease, dementia with Lewy bodies, and related disorders. Cognitive impairment is recapitulated in several αSYN transgenic mouse lines. However, the mechanisms of dysfunction in affected neurons are largely unknown. Here we measured neuronal activity induced gene products in the limbic system of αSYN transgenic mice upon fear conditioning (FC. Induction of the synaptic plasticity marker c-Fos was significantly reduced in the amygdala and hippocampus of (Thy1-h[A30P]αSYN transgenic mice in an age-dependent manner. Similarly, the neuronal activity inducible polo-like kinase 2 (Plk2 that can phosphorylate αSYN at the pathological site serine-129 was up-regulated in both brain regions upon FC. Plk2 inductions were also significantly impaired in aged (Thy1-h[A30P]αSYN transgenic mice, both in the amygdala and hippocampus. Plk2 inductions in the amygdala after FC were paralleled by a small but significant increase in the number of neuronal cell bodies immunopositive for serine-129 phosphorylated αSYN in young but not aged (Thy1-h[A30P]αSYN transgenic mice. In addition, we observed in the aged hippocampus a distinct type of apparently unmodified transgenic αSYN profiles resembling synaptic accumulations of αSYN. Thus, the cognitive decline observed in aged αSYN transgenic mice might be due to impairment of neurotransmission and synaptic plasticity in the limbic system by distinct αSYN species.

Dietary long chain n-3 polyunsaturated fatty acids prevent impaired social behaviour and normalize brain dopamine levels in food allergic mice

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de Theije, Caroline G M; van den Elsen, Lieke W J; Willemsen, Linette E M; Milosevic, Vanja; Korte-Bouws, Gerdien A H; Lopes da Silva, Sofia; Broersen, Laus M; Korte, S Mechiel; Olivier, Berend; Garssen, Johan; Kraneveld, Aletta D

2015-01-01

Allergy is suggested to exacerbate impaired behaviour in children with neurodevelopmental disorders. We have previously shown that food allergy impaired social behaviour in mice. Dietary fatty acid composition may affect both the immune and nervous system. The aim of this study was to assess the

Inability to acquire spatial information and deploy spatial search strategies in mice with lesions in dorsomedial striatum.

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Pooters, Tine; Gantois, Ilse; Vermaercke, Ben; D'Hooge, Rudi

2016-02-01

Dorsal striatum has been shown to contribute to spatial learning and memory, but the role of striatal subregions in this important aspect of cognitive functioning remains unclear. Moreover, the spatial-cognitive mechanisms that underlie the involvement of these regions in spatial navigation have scarcely been studied. We therefore compared spatial learning and memory performance in mice with lesions in dorsomedial (DMS) and dorsolateral striatum (DLS) using the hidden-platform version of the Morris water maze (MWM) task. Compared to sham-operated controls, animals with DMS damage were impaired during MWM acquisition training. These mice displayed delayed spatial learning, increased thigmotaxis, and increased search distance to the platform, in the absence of major motor dysfunction, working memory defects or changes in anxiety or exploration. They failed to show a preference for the target quadrant during probe trials, which further indicates that spatial reference memory was impaired in these animals. Search strategy analysis moreover demonstrated that DMS-lesioned mice were unable to deploy cognitively advanced spatial search strategies. Conversely, MWM performance was barely affected in animals with lesions in DLS. In conclusion, our results indicate that DMS and DLS display differential functional involvement in spatial learning and memory. Our results show that DMS, but not DLS, is crucial for the ability of mice to acquire spatial information and their subsequent deployment of spatial search strategies. These data clearly identify DMS as a crucial brain structure for spatial learning and memory, which could explain the occurrence of neurocognitive impairments in brain disorders that affect the dorsal striatum. Copyright © 2015 Elsevier B.V. All rights reserved.

High dietary folate in pregnant mice leads to pseudo-MTHFR deficiency and altered methyl metabolism, with embryonic growth delay and short-term memory impairment in offspring.

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Bahous, Renata H; Jadavji, Nafisa M; Deng, Liyuan; Cosín-Tomás, Marta; Lu, Jessica; Malysheva, Olga; Leung, Kit-Yi; Ho, Ming-Kai; Pallàs, Mercè; Kaliman, Perla; Greene, Nicholas D E; Bedell, Barry J; Caudill, Marie A; Rozen, Rima

2017-03-01

Methylenetetrahydrofolate reductase (MTHFR) generates methyltetrahydrofolate for methylation reactions. Severe MTHFR deficiency results in homocystinuria and neurologic impairment. Mild MTHFR deficiency (677C > T polymorphism) increases risk for complex traits, including neuropsychiatric disorders. Although low dietary folate impacts brain development, recent concerns have focused on high folate intake following food fortification and increased vitamin use. Our goal was to determine whether high dietary folate during pregnancy affects brain development in murine offspring. Female mice were placed on control diet (CD) or folic acid-supplemented diet (FASD) throughout mating, pregnancy and lactation. Three-week-old male pups were evaluated for motor and cognitive function. Tissues from E17.5 embryos, pups and dams were collected for choline/methyl metabolite measurements, immunoblotting or gene expression of relevant enzymes. Brains were examined for morphology of hippocampus and cortex. Pups of FASD mothers displayed short-term memory impairment, decreased hippocampal size and decreased thickness of the dentate gyrus. MTHFR protein levels were reduced in FASD pup livers, with lower concentrations of phosphocholine and glycerophosphocholine in liver and hippocampus, respectively. FASD pup brains showed evidence of altered acetylcholine availability and Dnmt3a mRNA was reduced in cortex and hippocampus. E17.5 embryos and placentas from FASD dams were smaller. MTHFR protein and mRNA were reduced in embryonic liver, with lower concentrations of choline, betaine and phosphocholine. Embryonic brain displayed altered development of cortical layers. In summary, high folate intake during pregnancy leads to pseudo-MTHFR deficiency, disturbed choline/methyl metabolism, embryonic growth delay and memory impairment in offspring. These findings highlight the unintended negative consequences of supplemental folic acid. © The Author 2017. Published by Oxford University Press.

Schizandrin, an Antioxidant Lignan from Schisandra chinensis, Ameliorates Aβ1–42-Induced Memory Impairment in Mice

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Di Hu

2012-01-01

Full Text Available In the present study, we examined the effect of schisandrin (SCH of Schisandra chinensis on the amyloid-beta1–42- (Aβ1–42- induced memory impairment in mice and elucidated the possible antioxidative mechanism. Mice were intracerebroventricular (i.c.v. injected with the aggregated Aβ1–42 and then treated with SCH (4, 12, and 36 mg/kg body weight or donepezil (DPZ, a reference drug (0.65 mg/kg by intragastric infusion for 14 days. Noncognitive disturbances and cognitive performance were evaluated by locomotor activity test, Y-maze test, and water maze test. Antioxidative enzyme activities including superoxide dismutase (SOD and glutathione peroxidase (GSH-px and levels of malondialdehyde (MDA, glutathione (GSH, and oxidized glutathione (GSSG within the cerebral cortex and hippocampus of mice were measured to elucidate the mechanism. Our results showed that SCH significantly improved Aβ1–42-induced short-term and spatial reference memory impairments in Y-maze test and water maze test. Furthermore, in the cerebral cortex and hippocampus of mice, SOD and GSH-px activities, GSH level, and GSH/GSSG ratio were increased, and levels of MDA and GSSG were decreased by the treatment of SCH. These results suggest that SCH is a potential cognitive enhancer against Alzheimer’s disease through antioxidative action.

Exposure to marijuana smoke impairs memory retrieval in mice.

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Niyuhire, Floride; Varvel, Stephen A; Martin, Billy R; Lichtman, Aron H

2007-09-01

Marijuana (Cannabis sativa) and its primary psychoactive component, delta-9-tetrahydrocannabinol (Delta(9)-THC), have long been known to disrupt cognition in humans. Although Delta(9)-THC and other cannabinoids disrupt performance in a wide range of animal models of learning and memory, few studies have investigated the effects of smoked marijuana in these paradigms. Moreover, in preclinical studies, cannabinoids are generally administered before acquisition, and because retention is generally evaluated soon afterward, it is difficult to distinguish between processes related to acquisition and retrieval. In the present study, we investigated the specific effects of marijuana smoke and injected Delta(9)-THC on acquisition versus memory retrieval in a mouse repeated acquisition Morris water-maze task. To distinguish between these processes, subjects were administered Delta(9)-THC or they were exposed to marijuana smoke either 30 min before acquisition or 30 min before the retention test. Inhalation of marijuana smoke or injected Delta(9)-THC impaired the ability of the mice to learn the location of the hidden platform and to recall the platform location once learning had already taken place. In contrast, neither drug impaired performance in a cued task in which the platform was made visible. Finally, the cannabinoid-1 (CB(1)) receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide HCl (rimonabant) blocked the memory disruptive effects of both Delta(9)-THC and marijuana. These data represent the first evidence demonstrating that marijuana impairs memory retrieval through a CB(1) receptor mechanism of action and independently of its effects on sensorimotor performance, motivation, and initial acquisition.

Sarcosine attenuates toluene-induced motor incoordination, memory impairment, and hypothermia but not brain stimulation reward enhancement in mice

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Chan, Ming-Huan [Department of Pharmacology and Toxicology, Tzu Chi University, Hualien, Taiwan (China); Institute of Neuroscience, National Changchi University, Taipei, Taiwan (China); Chung, Shiang-Sheng [Department of Pharmacology and Toxicology, Tzu Chi University, Hualien, Taiwan (China); Department of Pharmacy, Yuli Veterans Hospital, Hualien, Taiwan (China); Stoker, Astrid K.; Markou, Athina [Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA (United States); Chen, Hwei-Hsien, E-mail: hwei@nhri.org.tw [Department of Pharmacology and Toxicology, Tzu Chi University, Hualien, Taiwan (China); Division of Mental Health and Addiction Medicine, Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli County, Taiwan (China)

2012-12-01

Toluene, a widely used and commonly abused organic solvent, produces various behavioral disturbances, including motor incoordination and cognitive impairment. Toluene alters the function of a large number of receptors and ion channels. Blockade of N-methyl-D-aspartate (NMDA) receptors has been suggested to play a critical role in toluene-induced behavioral manifestations. The present study determined the effects of various toluene doses on motor coordination, recognition memory, body temperature, and intracranial self-stimulation (ICSS) thresholds in mice. Additionally, the effects of sarcosine on the behavioral and physiological effects induced by toluene were evaluated. Sarcosine may reverse toluene-induced behavioral manifestations by acting as an NMDA receptor co-agonist and by inhibiting the effects of the type I glycine transporter (GlyT1). Mice were treated with toluene alone or combined with sarcosine pretreatment and assessed for rotarod performance, object recognition memory, rectal temperature, and ICSS thresholds. Toluene dose-dependently induced motor incoordination, recognition memory impairment, and hypothermia and lowered ICSS thresholds. Sarcosine pretreatment reversed toluene-induced changes in rotarod performance, novel object recognition, and rectal temperature but not ICSS thresholds. These findings suggest that the sarcosine-induced potentiation of NMDA receptors may reverse motor incoordination, memory impairment, and hypothermia but not the enhancement of brain stimulation reward function associated with toluene exposure. Sarcosine may be a promising compound to prevent acute toluene intoxications by occupational or intentional exposure. -- Highlights: ► Toluene induces impairments in Rotarod test and novel object recognition test. ► Toluene lowers rectal temperature and ICSS thresholds in mice. ► Sarcosine reverses toluene-induced changes in motor, memory and body temperature. ► Sarcosine pretreatment does not affect toluene

Sarcosine attenuates toluene-induced motor incoordination, memory impairment, and hypothermia but not brain stimulation reward enhancement in mice

International Nuclear Information System (INIS)

Chan, Ming-Huan; Chung, Shiang-Sheng; Stoker, Astrid K.; Markou, Athina; Chen, Hwei-Hsien

2012-01-01

Toluene, a widely used and commonly abused organic solvent, produces various behavioral disturbances, including motor incoordination and cognitive impairment. Toluene alters the function of a large number of receptors and ion channels. Blockade of N-methyl-D-aspartate (NMDA) receptors has been suggested to play a critical role in toluene-induced behavioral manifestations. The present study determined the effects of various toluene doses on motor coordination, recognition memory, body temperature, and intracranial self-stimulation (ICSS) thresholds in mice. Additionally, the effects of sarcosine on the behavioral and physiological effects induced by toluene were evaluated. Sarcosine may reverse toluene-induced behavioral manifestations by acting as an NMDA receptor co-agonist and by inhibiting the effects of the type I glycine transporter (GlyT1). Mice were treated with toluene alone or combined with sarcosine pretreatment and assessed for rotarod performance, object recognition memory, rectal temperature, and ICSS thresholds. Toluene dose-dependently induced motor incoordination, recognition memory impairment, and hypothermia and lowered ICSS thresholds. Sarcosine pretreatment reversed toluene-induced changes in rotarod performance, novel object recognition, and rectal temperature but not ICSS thresholds. These findings suggest that the sarcosine-induced potentiation of NMDA receptors may reverse motor incoordination, memory impairment, and hypothermia but not the enhancement of brain stimulation reward function associated with toluene exposure. Sarcosine may be a promising compound to prevent acute toluene intoxications by occupational or intentional exposure. -- Highlights: ► Toluene induces impairments in Rotarod test and novel object recognition test. ► Toluene lowers rectal temperature and ICSS thresholds in mice. ► Sarcosine reverses toluene-induced changes in motor, memory and body temperature. ► Sarcosine pretreatment does not affect toluene

Transcranial low-level laser therapy improves brain mitochondrial function and cognitive impairment in D-galactose-induced aging mice.

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Salehpour, Farzad; Ahmadian, Nahid; Rasta, Seyed Hossein; Farhoudi, Mehdi; Karimi, Pouran; Sadigh-Eteghad, Saeed

2017-10-01

Mitochondrial function plays a key role in the aging-related cognitive impairment, and photoneuromodulation of mitochondria by transcranial low-level laser therapy (LLLT) may contribute to its improvement. This study focused on the transcranial LLLT effects on the D-galactose (DG)-induced mitochondrial dysfunction, apoptosis, and cognitive impairment in mice. For this purpose, red and near-infrared (NIR) laser wavelengths (660 and 810 nm) at 2 different fluencies (4 and 8 J/cm 2 ) at 10-Hz pulsed wave mode were administrated transcranially 3 d/wk in DG-received (500 mg/kg/subcutaneous) mice model of aging for 6 weeks. Spatial and episodic-like memories were assessed by the Barnes maze and What-Where-Which (WWWhich) tasks. Brain tissues were analyzed for mitochondrial function including active mitochondria, adenosine triphosphate, and reactive oxygen species levels, as well as membrane potential and cytochrome c oxidase activity. Apoptosis-related biomarkers, namely, Bax, Bcl-2, and caspase-3 were evaluated by Western blotting method. Laser treatments at wavelengths of 660 and 810 nm at 8 J/cm 2 attenuated DG-impaired spatial and episodic-like memories. Also, results showed an obvious improvement in the mitochondrial function aspects and modulatory effects on apoptotic markers in aged mice. However, same wavelengths at the fluency of 4 J/cm 2 had poor effect on the behavioral and molecular indexes in aging model. This data indicates that transcranial LLLT at both of red and NIR wavelengths at the fluency of 8 J/cm 2 has a potential to ameliorate aging-induced mitochondrial dysfunction, apoptosis, and cognitive impairment. Copyright © 2017 Elsevier Inc. All rights reserved.

Myg1-deficient mice display alterations in stress-induced responses and reduction of sex-dependent behavioural differences.

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Philips, Mari-Anne; Abramov, Urho; Lilleväli, Kersti; Luuk, Hendrik; Kurrikoff, Kaido; Raud, Sirli; Plaas, Mario; Innos, Jürgen; Puussaar, Triinu; Kõks, Sulev; Vasar, Eero

2010-02-11

Myg1 (Melanocyte proliferating gene 1) is a highly conserved and ubiquitously expressed gene, which encodes a protein with mitochondrial and nuclear localization. In the current study we demonstrate a gradual decline of Myg1 expression during the postnatal development of the mouse brain that suggests relevance for Myg1 in developmental processes. To study the effects of Myg1 loss-of-function, we created Myg1-deficient (-/-) mice by displacing the entire coding sequence of the gene. Initial phenotyping, covering a multitude of behavioural, cognitive, neurological, physiological and stress-related responses, revealed that homozygous Myg1 (-/-) mice are vital, fertile and display no gross abnormalities. Myg1 (-/-) mice showed an inconsistent pattern of altered anxiety-like behaviour in different tests. The plus-maze and social interaction tests revealed that male Myg1 (-/-) mice were significantly less anxious than their wild-type littermates; female (-/-) mice showed increased anxiety in the locomotor activity arena. Restraint-stress significantly reduced the expression of the Myg1 gene in the prefrontal cortex of female wild-type mice and restrained female (-/-) mice showed a blunted corticosterone response, suggesting involvement of Myg1 in stress-induced responses. The main finding of the present study was that Myg1 invalidation decreases several behavioural differences between male and female animals that were obvious in wild-type mice, indicating that Myg1 contributes to the expression of sex-dependent behavioural differences in mice. Taken together, we provide evidence for the involvement of Myg1 in anxiety- and stress-related responses and suggest that Myg1 contributes to the expression of sex-dependent behavioural differences.

Relaxin-3 inputs target hippocampal interneurons and deletion of hilar relaxin-3 receptors in "floxed-RXFP3" mice impairs spatial memory.

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Haidar, M; Guèvremont, G; Zhang, C; Bathgate, R A D; Timofeeva, E; Smith, C M; Gundlach, A L

2017-05-01

Hippocampus is innervated by γ-aminobutyric acid (GABA) "projection" neurons of the nucleus incertus (NI), including a population expressing the neuropeptide, relaxin-3 (RLN3). In studies aimed at gaining an understanding of the role of RLN3 signaling in hippocampus via its G i/o -protein-coupled receptor, RXFP3, we examined the distribution of RLN3-immunoreactive nerve fibres and RXFP3 mRNA-positive neurons in relation to hippocampal GABA neuron populations. RLN3-positive elements were detected in close-apposition with a substantial population of somatostatin (SST)- and GABA-immunoreactive neurons, and a smaller population of parvalbumin- and calretinin-immunoreactive neurons in different hippocampal areas, consistent with the relative distribution patterns of RXFP3 mRNA and these marker transcripts. In light of the functional importance of the dentate gyrus (DG) hilus in learning and memory, and our anatomical data, we examined the possible influence of RLN3/RXFP3 signaling in this region on spatial memory. Using viral-based Cre/LoxP recombination methods and adult mice with a floxed Rxfp3 gene, we deleted Rxfp3 from DG hilar neurons and assessed spatial memory performance and affective behaviors. Following infusions of an AAV (1/2) -Cre-IRES-eGFP vector, Cre expression was observed in DG hilar neurons, including SST-positive cells, and in situ hybridization histochemistry for RXFP3 mRNA confirmed receptor depletion relative to levels in floxed-RXFP3 mice infused with an AAV (1/2) -eGFP (control) vector. RXFP3 depletion within the DG hilus impaired spatial reference memory in an appetitive T-maze task reflected by a reduced percentage of correct choices and increased time to meet criteria, relative to control. In a continuous spontaneous alternation Y-maze task, RXFP3-depleted mice made fewer alternations in the first minute, suggesting impairment of spatial working memory. However, RXFP3-depleted and control mice displayed similar locomotor activity, anxiety

miR-378 Activates the Pyruvate-PEP Futile Cycle and Enhances Lipolysis to Ameliorate Obesity in Mice

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Yong Zhang

2016-03-01

Full Text Available Obesity has been linked to many health problems, such as diabetes. However, there is no drug that effectively treats obesity. Here, we reveal that miR-378 transgenic mice display reduced fat mass, enhanced lipolysis, and increased energy expenditure. Notably, administering AgomiR-378 prevents and ameliorates obesity in mice. We also found that the energy deficiency seen in miR-378 transgenic mice was due to impaired glucose metabolism. This impairment was caused by an activated pyruvate-PEP futile cycle via the miR-378-Akt1-FoxO1-PEPCK pathway in skeletal muscle and enhanced lipolysis in adipose tissues mediated by miR-378-SCD1. Our findings demonstrate that activating the pyruvate-PEP futile cycle in skeletal muscle is the primary cause of elevated lipolysis in adipose tissues of miR-378 transgenic mice, and it helps orchestrate the crosstalk between muscle and fat to control energy homeostasis in mice. Thus, miR-378 may serve as a promising agent for preventing and treating obesity in humans.

Mice with Sort1 deficiency display normal cognition but elevated anxiety-like behavior.

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Ruan, Chun-Sheng; Yang, Chun-Rui; Li, Jia-Yi; Luo, Hai-Yun; Bobrovskaya, Larisa; Zhou, Xin-Fu

2016-07-01

Exposure to stressful life events plays a central role in the development of mood disorders in vulnerable individuals. However, the mechanisms that link mood disorders to stress are poorly understood. Brain-derived neurotrophic factor (BDNF) has long been implicated in positive regulation of depression and anxiety, while its precursor (proBDNF) recently showed an opposing effect on such mental illnesses. P75(NTR) and sortilin are co-receptors of proBDNF, however, the role of these receptors in mood regulation is not established. Here, we aimed to investigate the role of sortilin in regulating mood-related behaviors and its role in the proBDNF-mediated mood abnormality in mice. We found that sortilin was up-regulated in neocortex (by 78.3%) and hippocampus (by 111%) of chronically stressed mice as assessed by western blot analysis. These changes were associated with decreased mobility in the open field test and increased depression-like behavior in the forced swimming test. We also found that sortilin deficiency in mice resulted in hyperlocomotion in the open field test and increased anxiety-like behavior in both the open field and elevated plus maze tests. No depression-like behavior in the forced swimming test and no deficit in spatial cognition in the Morris water maze test were found in the Sort1-deficient mice. Moreover, the intracellular and extracellular levels of mature BDNF and proBDNF were not changed when sortilin was absent in vivo and in vitro. Finally, we found that both WT and Sort1-deficient mice injected with proBDNF in lateral ventricle displayed increased depression-like behavior in the forced swimming test but not anxiety-like behaviors in the open field and elevated plus maze tests. The present study suggests that sortilin functions as a negative regulator of mood performance and can be a therapeutic target for the treatment of mental illness. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

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

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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

Prolonged Ketamine Effects in Sp4 Hypomorphic Mice: Mimicking Phenotypes of Schizophrenia.

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Baohu Ji

Full Text Available It has been well established that schizophrenia patients display impaired NMDA receptor (NMDAR functions as well as exacerbation of symptoms in response to NMDAR antagonists. Abnormal NMDAR signaling presumably contributes to cognitive deficits which substantially contribute to functional disability in schizophrenia. Establishing a mouse genetic model will help investigate molecular mechanisms of hypoglutmatergic neurotransmission in schizophrenia. Here, we examined the responses of Sp4 hypomorphic mice to NMDAR antagonists in electroencephalography and various behavioral paradigms. Sp4 hypomorphic mice, previously reported to have reduced NMDAR1 expression and LTP deficit in hippocampal CA1, displayed increased sensitivity and prolonged responses to NMDAR antagonists. Molecular studies demonstrated reduced expression of glutamic acid decarboxylase 67 (GAD67 in both cortex and hippocampus, consistent with abnormal gamma oscillations in Sp4 hypomorphic mice. On the other hand, human SP4 gene was reported to be deleted in schizophrenia. Several human genetic studies suggested the association of SP4 gene with schizophrenia and other psychiatric disorders. Therefore, elucidation of the Sp4 molecular pathway in Sp4 hypomorphic mice may provide novel insights to our understanding of abnormal NMDAR signaling in schizophrenia.

Bacopa monniera Attenuates Scopolamine-Induced Impairment of Spatial Memory in Mice

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Manish Kumar Saraf

2011-01-01

Full Text Available Scopolamine, an anticholinergic, is an attractive amnesic agent for discerning the action of candidate antiamnesic drugs. Bacopa monniera Linn (Syn. Brahmi is one such antiamnesic agent that is frequently used in the ancient Indian medical system. We have earlier reported the reversal of diazepam-induced amnesia with B. monniera. In this study we wanted to test if scopolamine-induced impairment of spatial memory can also be ameliorated by B. monniera using water maze mouse model. The objective of study was to study the effect of B. monniera on scopolamine-induced amnesia. We employed Morris water maze scale to test the amnesic effect of scopolamine and its reversal by B. monniera. Rotarod test was conducted to screen muscle coordination activity of mice. Scopolamine significantly impaired the acquisition and retrieval of memory producing both anterograde and retrograde amnesia. Bacopa monniera extract was able to reverse both anterograde and retrograde amnesia. We propose that B. monniera's effects on cholinergic system may be helpful for developing alternative therapeutic approaches for the treatment of Alzheimer's disease.

Vitamin B1-deficient mice show impairment of hippocampus-dependent memory formation and loss of hippocampal neurons and dendritic spines: potential microendophenotypes of Wernicke-Korsakoff syndrome.

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Inaba, Hiroyoshi; Kishimoto, Takuya; Oishi, Satoru; Nagata, Kan; Hasegawa, Shunsuke; Watanabe, Tamae; Kida, Satoshi

2016-12-01

Patients with severe Wernicke-Korsakoff syndrome (WKS) associated with vitamin B1 (thiamine) deficiency (TD) show enduring impairment of memory formation. The mechanisms of memory impairment induced by TD remain unknown. Here, we show that hippocampal degeneration is a potential microendophenotype (an endophenotype of brain disease at the cellular and synaptic levels) of WKS in pyrithiamine-induced thiamine deficiency (PTD) mice, a rodent model of WKS. PTD mice show deficits in the hippocampus-dependent memory formation, although they show normal hippocampus-independent memory. Similarly with WKS, impairments in memory formation did not recover even at 6 months after treatment with PTD. Importantly, PTD mice exhibit a decrease in neurons in the CA1, CA3, and dentate gyrus (DG) regions of the hippocampus and reduced density of wide dendritic spines in the DG. Our findings suggest that TD induces hippocampal degeneration, including the loss of neurons and spines, thereby leading to enduring impairment of hippocampus-dependent memory formation.

Vitamin B1-deficient mice show impairment of hippocampus-dependent memory formation and loss of hippocampal neurons and dendritic spines: potential microendophenotypes of Wernicke–Korsakoff syndrome

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Inaba, Hiroyoshi; Kishimoto, Takuya; Oishi, Satoru; Nagata, Kan; Hasegawa, Shunsuke; Watanabe, Tamae; Kida, Satoshi

2016-01-01

Patients with severe Wernicke–Korsakoff syndrome (WKS) associated with vitamin B1 (thiamine) deficiency (TD) show enduring impairment of memory formation. The mechanisms of memory impairment induced by TD remain unknown. Here, we show that hippocampal degeneration is a potential microendophenotype (an endophenotype of brain disease at the cellular and synaptic levels) of WKS in pyrithiamine-induced thiamine deficiency (PTD) mice, a rodent model of WKS. PTD mice show deficits in the hippocampus-dependent memory formation, although they show normal hippocampus-independent memory. Similarly with WKS, impairments in memory formation did not recover even at 6 months after treatment with PTD. Importantly, PTD mice exhibit a decrease in neurons in the CA1, CA3, and dentate gyrus (DG) regions of the hippocampus and reduced density of wide dendritic spines in the DG. Our findings suggest that TD induces hippocampal degeneration, including the loss of neurons and spines, thereby leading to enduring impairment of hippocampus-dependent memory formation. PMID:27576603

Cognitive Ameliorating Effect of Acanthopanax koreanum Against Scopolamine-Induced Memory Impairment in Mice.

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Lee, Sunhee; Park, Ho Jae; Jeon, Se Jin; Kim, Eunji; Lee, Hyung Eun; Kim, Haneul; Kwon, Yubeen; Zhang, Jiabao; Jung, In Ho; Ryu, Jong Hoon

2017-03-01

Acanthopanax koreanum Nakai (Araliaceae) is one of the most widely cultivated medicinal plants in Jeju Island, Korea, and the roots and stem bark of A. koreanum have been traditionally used as a tonic agent for general weakness. However, the use of A. koreanum for general weakness observed in the elderly, including those with declined cognitive function, has not been intensively investigated. This study was performed to investigate the effect of the ethanol extract of A. koreanum (EEAK) on cholinergic blockade-induced memory impairment in mice. To evaluate the ameliorating effects of EEAK against scopolamine-induced memory impairment, mice were orally administered EEAK (25, 50, 100, or 200 mg/kg), and several behavioral tasks, including a passive avoidance task, the Y-maze, and a novel object recognition task, were employed. Besides, western blot analysis was conducted to examine whether EEAK affected memory-associated signaling molecules, such as protein kinase B (Akt), Ca 2+ /calmodulin-dependent protein kinase II (CaMKII), and cAMP response element-binding protein (CREB). The administration of EEAK (100 or 200 mg/kg, p.o.) significantly ameliorated the scopolamine-induced cognitive impairment in the passive avoidance task, the Y-maze, and the novel object recognition task. The phosphorylation levels of both Akt and CaMKII were significantly increased by approximately two-fold compared with the control group because of the administration of EEAK (100 or 200 mg/kg) (p cognitive dysfunction induced by the cholinergic blockade, in part, via several memory-associated signaling molecules and may hold therapeutic potential against cognitive dysfunction, such as that presented in neurodegenerative diseases, for example, Alzheimer's disease. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Amelioration of behavioral abnormalities in BH(4-deficient mice by dietary supplementation of tyrosine.

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Sang Su Kwak

Full Text Available This study reports an amelioration of abnormal motor behaviors in tetrahydrobiopterin (BH4-deficient Spr (-/- mice by the dietary supplementation of tyrosine. Since BH4 is an essential cofactor for the conversion of phenylalanine into tyrosine as well as the synthesis of dopamine neurotransmitter within the central nervous system, the levels of tyrosine and dopamine were severely reduced in brains of BH4-deficient Spr (-/- mice. We found that Spr (-/- mice display variable 'open-field' behaviors, impaired motor functions on the 'rotating rod', and dystonic 'hind-limb clasping'. In this study, we report that these aberrant motor deficits displayed by Spr (-/- mice were ameliorated by the therapeutic tyrosine diet for 10 days. This study also suggests that dopamine deficiency in brains of Spr (-/- mice may not be the biological feature of aberrant motor behaviors associated with BH4 deficiency. Brain levels of dopamine (DA and its metabolites in Spr (-/- mice were not substantially increased by the dietary tyrosine therapy. However, we found that mTORC1 activity severely suppressed in brains of Spr (-/- mice fed a normal diet was restored 10 days after feeding the mice the tyrosine diet. The present study proposes that brain mTORC1 signaling pathway is one of the potential targets in understanding abnormal motor behaviors associated with BH4-deficiency.

Impaired compensation to femoral artery ligation in diet-induced obese mice is primarily mediated via suppression of collateral growth by Nox2 and p47phox.

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DiStasi, Matthew R; Mund, Julie A; Bohlen, H Glenn; Miller, Steven J; Ingram, David A; Dalsing, Michael C; Unthank, Joseph L

2015-10-01

The present study was undertaken to establish the role of NADPH oxidase (Nox) in impaired vascular compensation to arterial occlusion that occurs in the presence of risk factors associated with oxidative stress. Diet-induced obese (DIO) mice characterized by multiple comorbidities including diabetes and hyperlipidemia were used as a preclinical model. Arterial occlusion was induced by distal femoral artery ligation in lean and DIO mice. Proximal collateral arteries were identified as the site of major (∼70%) vascular resistance to calf perfusion by distal arterial pressures, which decreased from ∼80 to ∼30 mmHg with ligation in both lean and DIO mice. Two weeks after ligation, significant vascular compensation occurred in lean but not DIO mice as evidenced by increased perfusion (147 ± 48% vs. 49 ± 29%) and collateral diameter (151 ± 30% vs. 44 ± 17%). Vascular mRNA expression of p22(phox), Nox2, Nox4, and p47(phox) were all increased in DIO mice. Treatment of DIO mice with either apocynin or Nox2ds-tat or with whole body ablation of either Nox2 or p47(phox) ameliorated the impairment in both collateral growth and hindlimb perfusion. Multiparametric flow cytometry analysis demonstrated elevated levels of circulating monocytes in DIO mice without impaired mobilization and demargination after femoral artery ligation. These results establish collateral resistance as the major limitation to calf perfusion in this preclinical model, demonstrate than monocyte mobilization and demarginatin is not suppressed, implicate Nox2-p47(phox) interactions in the impairment of vascular compensation to arterial occlusion in DIO mice, and suggest that selective Nox component suppression/inhibition may be effective as either primary or adjuvant therapy for claudicants. Copyright © 2015 the American Physiological Society.

Behavioral testing of mice exposed to intermediate frequency magnetic fields indicates mild memory impairment.

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Kajal Kumari

Full Text Available Human exposure to intermediate frequency magnetic fields (MF is increasing due to applications like electronic article surveillance systems and induction heating cooking hobs. However, limited data is available on their possible health effects. The present study assessed behavioral and histopathological consequences of exposing mice to 7.5 kHz MF at 12 or 120 μT for 5 weeks. No effects were observed on body weight, spontaneous activity, motor coordination, level of anxiety or aggression. In the Morris swim task, mice in the 120 μT group showed less steep learning curve than the other groups, but did not differ from controls in their search bias in the probe test. The passive avoidance task indicated a clear impairment of memory over 48 h in the 120 μT group. No effects on astroglial activation or neurogenesis were observed in the hippocampus. The mRNA expression of brain-derived neurotrophic factor did not change but expression of the proinflammatory cytokine tumor necrosis factor alpha mRNA was significantly increased in the 120 μT group. These findings suggest that 7.5 kHz MF exposure may lead to mild learning and memory impairment, possibly through an inflammatory reaction in the hippocampus.

Perinatal exposure of mice to the pesticide DDT impairs energy expenditure and metabolism in adult female offspring.

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Michele La Merrill

Full Text Available Dichlorodiphenyltrichloroethane (DDT has been used extensively to control malaria, typhus, body lice and bubonic plague worldwide, until countries began restricting its use in the 1970s. Its use in malaria control continues in some countries according to recommendation by the World Health Organization. Individuals exposed to elevated levels of DDT and its metabolite dichlorodiphenyldichloroethylene (DDE have an increased prevalence of diabetes and insulin resistance. Here we hypothesize that perinatal exposure to DDT disrupts metabolic programming leading to impaired metabolism in adult offspring. To test this, we administered DDT to C57BL/6J mice from gestational day 11.5 to postnatal day 5 and studied their metabolic phenotype at several ages up to nine months. Perinatal DDT exposure reduced core body temperature, impaired cold tolerance, decreased energy expenditure, and produced a transient early-life increase in body fat in female offspring. When challenged with a high fat diet for 12 weeks in adulthood, female offspring perinatally exposed to DDT developed glucose intolerance, hyperinsulinemia, dyslipidemia, and altered bile acid metabolism. Perinatal DDT exposure combined with high fat feeding in adulthood further impaired thermogenesis as evidenced by reductions in core temperature and in the expression of numerous RNA that promote thermogenesis and substrate utilization in the brown adipose tissue of adult female mice. These observations suggest that perinatal DDT exposure impairs thermogenesis and the metabolism of carbohydrates and lipids which may increase susceptibility to the metabolic syndrome in adult female offspring.

Perinatal Exposure of Mice to the Pesticide DDT Impairs Energy Expenditure and Metabolism in Adult Female Offspring

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La Merrill, Michele; Karey, Emma; Moshier, Erin; Lindtner, Claudia; La Frano, Michael R.; Newman, John W.; Buettner, Christoph

2014-01-01

Dichlorodiphenyltrichloroethane (DDT) has been used extensively to control malaria, typhus, body lice and bubonic plague worldwide, until countries began restricting its use in the 1970s. Its use in malaria control continues in some countries according to recommendation by the World Health Organization. Individuals exposed to elevated levels of DDT and its metabolite dichlorodiphenyldichloroethylene (DDE) have an increased prevalence of diabetes and insulin resistance. Here we hypothesize that perinatal exposure to DDT disrupts metabolic programming leading to impaired metabolism in adult offspring. To test this, we administered DDT to C57BL/6J mice from gestational day 11.5 to postnatal day 5 and studied their metabolic phenotype at several ages up to nine months. Perinatal DDT exposure reduced core body temperature, impaired cold tolerance, decreased energy expenditure, and produced a transient early-life increase in body fat in female offspring. When challenged with a high fat diet for 12 weeks in adulthood, female offspring perinatally exposed to DDT developed glucose intolerance, hyperinsulinemia, dyslipidemia, and altered bile acid metabolism. Perinatal DDT exposure combined with high fat feeding in adulthood further impaired thermogenesis as evidenced by reductions in core temperature and in the expression of numerous RNA that promote thermogenesis and substrate utilization in the brown adipose tissue of adult female mice. These observations suggest that perinatal DDT exposure impairs thermogenesis and the metabolism of carbohydrates and lipids which may increase susceptibility to the metabolic syndrome in adult female offspring. PMID:25076055

Polygalasaponin XXXII, a triterpenoid saponin from Polygalae Radix, attenuates scopolamine-induced cognitive impairments in mice.

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Zhou, Heng; Xue, Wei; Chu, Shi-Feng; Wang, Zhen-Zhen; Li, Chuang-Jun; Jiang, Yi-Na; Luo, Lin-Ming; Luo, Piao; Li, Gang; Zhang, Dong-Ming; Chen, Nai-Hong

2016-08-01

Recent studies show that the extract of a Chinese herb Polygalae Radix exerts cognition-enhancing actions in rats and humans. The aim of this study was to characterize the pharmacological profiles of active compounds extracted from Polygalae Radix. Two fractions P3 and P6 and two compounds PTM-15 and polygalasaponin XXXII (PGS32) were prepared. Neuroprotective effects were evaluated in primary cortical neurons exposed to high concentration glutamate, serum deficiency or H2O2. Anti-dementia actions were assessed in scopolamine-induced amnesia in mice using step-through avoidance tests and channel water maze tests. After conducting the channel water maze tests, TrkB phosphorylation in mouse hippocampus was detected using Western blotting. Long-term potentiation (LTP) was induced in the dentate gyrus in adult rats; PGS32 (5 μL 400 μmol/L) was injected into the lateral cerebral ventricle 20 min after high frequency stimulation (HFS). Compared to the fraction P6, the fraction P3 showed more prominent neuroprotective effects in vitro and cognition-enhancing effects in scopolamine-induced amnesia in mice. One active compound PGS32 in the fraction P3 exerted potent cognition-enhancing action: oral administration of PGS32 (0.125 mg·kg(-1)·d(-1)) for 19 days abolished scopolamine-induced memory impairment in mice. Furthermore, PGS32 (0.5 and 2 mg·kg(-1)·d(-1)) significantly stimulated the phosphorylation of TrkB in the hippocampus. Intracerebroventricular injection of PGS32 significantly enhanced HFS-induced LTP in the dentate gyrus of rats. PGS32 attenuates scopolamine-induced cognitive impairments in mice, suggesting that it has a potential for the treatment of cognitive dysfunction and dementia.

RhoE deficiency produces postnatal lethality, profound motor deficits and neurodevelopmental delay in mice.

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Enric Mocholí

Full Text Available Rnd proteins are a subfamily of Rho GTPases involved in the control of actin cytoskeleton dynamics and other cell functions such as motility, proliferation and survival. Unlike other members of the Rho family, Rnd proteins lack GTPase activity and therefore remain constitutively active. We have recently described that RhoE/Rnd3 is expressed in the Central Nervous System and that it has a role in promoting neurite formation. Despite their possible relevance during development, the role of Rnd proteins in vivo is not known. To get insight into the in vivo function of RhoE we have generated mice lacking RhoE expression by an exon trapping cassette. RhoE null mice (RhoE gt/gt are smaller at birth, display growth retardation and early postnatal death since only half of RhoE gt/gt mice survive beyond postnatal day (PD 15 and 100% are dead by PD 29. RhoE gt/gt mice show an abnormal body position with profound motor impairment and impaired performance in most neurobehavioral tests. Null mutant mice are hypoactive, show an immature locomotor pattern and display a significant delay in the appearance of the hindlimb mature responses. Moreover, they perform worse than the control littermates in the wire suspension, vertical climbing and clinging, righting reflex and negative geotaxis tests. Also, RhoE ablation results in a delay of neuromuscular maturation and in a reduction in the number of spinal motor neurons. Finally, RhoE gt/gt mice lack the common peroneal nerve and, consequently, show a complete atrophy of the target muscles. This is the first model to study the in vivo functions of a member of the Rnd subfamily of proteins, revealing the important role of Rnd3/RhoE in the normal development and suggesting the possible involvement of this protein in neurological disorders.

Gamma aminobutyric acid transporter subtype 1 gene knockout mice: a new model for attention deficit/hyperactivity disorder

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Ping Yang; Guoqiang Cai; Youqing Cai; Jian Fei; Guoxiang Liu

2013-01-01

Attention deficit/hyperactivity disorder (ADHD) is characterized by hyperactivity,impaired sustained attention,impulsivity,and is usually accompanied by varying degrees of learning difficulties and lack of motor coordination.However,the pathophysiology and etiology of ADHD remain inconclusive so far.Our previous studies have demonstrated that the gamma aminobutyric acid transporter subtype 1 (GAT1) gene knockout (ko) mouse (gat1-/-)is hyperactive and exhibited impaired memory performance in the Morris water maze.In the current study,we found that the gat1-/-mice showed low levels of attentional focusing and increased impulsivity.In addition,the gat1-/-mice displayed ataxia characterized by defects in motor coordination and balance skills.The hyperactivity in the ko mice was reduced by both methylphenidate and amphetamine.Collectively,these results suggest that GAT1 ko mouse is a new animal model for ADHD studying and GAT1 may be a new target to treat ADHD.

7,8-Dihydroxyflavone Ameliorates Cognitive Impairment by Inhibiting Expression of Tau Pathology in ApoE-Knockout Mice

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Yang Tan

2016-11-01

Full Text Available 7,8-Dihydroxyflavone (7,8-DHF, a tyrosine kinase B (TrkB agonist that mimics the neuroprotective properties of brain-derived neurotrophic factor, which can not efficiently deliver into the brain, has been reported to be useful in ameliorating cognitive impairment in many diseases. Researches have indicated that apolipoprotein E-knockout (ApoE-KO mouse was associated with cognitive alteration via various mechanisms. Our present study investigated the possible mechanisms of cognitive impairment of ApoE-KO mouse fed with western type diet and the protective effects of 7,8-DHF in improving spatial learning and memory in ApoE-KO mouse. 5-weeks-old ApoE-KO mice and C57BL/6 mice were chronically treated with 7,8-DHF (with a dosage of 5mg/kg or vehicles orally for 25 weeks, and then subjected to Morris water maze at the age of 30 weeks to evaluate the cognitive performances. Afterwards, histology analysis and western blotting were performed. Spatial learning and memory deficits were observed in ApoE-KO mice, which were consistent with higher expression of active-asparaginyl endopeptidase (active-AEP as well as AEP-derived truncated tauN368 compared with normal group. In addition to that, long-term treatment of 7,8-DHF dramatically ameliorated cognitive decline in ApoE-KO mice, accompanied by the activation in phosphorylated protein kinase B (Akt/glycogen synthase kinase-3β (GSK-3β pathway and down-regulated expression of tau S396 and PHF-tau (phosphorylated tau at ser396 and ser404 epitope. These findings suggested that cognitive impairment of ApoE-KO mouse might associate with tau pathology and 7,8-DHF could activate AKT and then phosphorylate its downstream molecule to inhibit expression of abnormal tau, meanwhile, 7,8-DHF could reduce the expression of active-AEP and then inhibit production of truncated tauN368.

Mice lacking the synaptic adhesion molecule Neph2/Kirrel3 display moderate hyperactivity and defective novel object preference

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Su Yeon eChoi

2015-07-01

Full Text Available Synaptic adhesion molecules regulate diverse aspects of neuronal synapse development, including synapse specificity, formation, and maturation. Neph2, also known as Kirrel3, is an immunoglobulin superfamily adhesion molecule implicated in intellectual disability, neurocognitive delay associated with Jacobsen syndrome, and autism spectrum disorders. We here report mice lacking Neph2 (Neph2–/– mice display moderate hyperactivity in a familiar but not novel environment and novel object recognition deficit with normal performances in Morris water maze spatial learning and memory, contextual fear conditioning and extinction, and pattern separation tests. These mice show normal levels of anxiety-like behaviors, social interaction, and repetitive behaviors. At the synapse level, Neph2–/– dentate gyrus granule cells exhibit unaltered dendritic spine density and spontaneous excitatory synaptic transmission. These results suggest that Neph2 is important for normal locomotor activity and object recognition memory.

Environmental Enrichment Ameliorates Behavioral Impairments Modeling Schizophrenia in Mice Lacking Metabotropic Glutamate Receptor 5.

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Burrows, Emma L; McOmish, Caitlin E; Buret, Laetitia S; Van den Buuse, Maarten; Hannan, Anthony J

2015-07-01

Schizophrenia arises from a complex interplay between genetic and environmental factors. Abnormalities in glutamatergic signaling have been proposed to underlie the emergence of symptoms, in light of various lines of evidence, including the psychotomimetic effects of NMDA receptor antagonists. Metabotropic glutamate receptor 5 (mGlu5) has also been implicated in the disorder, and has been shown to physically interact with NMDA receptors. To clarify the role of mGlu5-dependent behavioral expression by environmental factors, we assessed mGlu5 knockout (KO) mice after exposure to environmental enrichment (EE) or reared under standard conditions. The mGlu5 KO mice showed reduced prepulse inhibition (PPI), long-term memory deficits, and spontaneous locomotor hyperactivity, which were all attenuated by EE. Examining the cellular impact of genetic and environmental manipulation, we show that EE significantly increased pyramidal cell dendritic branching and BDNF protein levels in the hippocampus of wild-type mice; however, mGlu5 KO mice were resistant to these alterations, suggesting that mGlu5 is critical to these responses. A selective effect of EE on the behavioral response to the NMDA receptor antagonist MK-801 in mGlu5 KO mice was seen. MK-801-induced hyperlocomotion was further potentiated in enriched mGlu5 KO mice and treatment with MK-801 reinstated PPI disruption in EE mGlu5 KO mice only, a response that is absent under standard housing conditions. Together, these results demonstrate an important role for mGlu5 in environmental modulation of schizophrenia-related behavioral impairments. Furthermore, this role of the mGlu5 receptor is mediated by interaction with NMDA receptor function, which may inform development of novel therapeutics.

Indirubin Derivative 7-Bromoindirubin-3-Oxime (7Bio Attenuates Aβ Oligomer-Induced Cognitive Impairments in Mice

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Liping Chen

2017-11-01

Full Text Available Indirubins are natural occurring alkaloids extracted from indigo dye-containing plants. Indirubins could inhibit various kinases, and might be used to treat chronic myelocytic leukemia, cancer and neurodegenerative disorders. 7-bromoindirubin-3-oxime (7Bio, an indirubin derivative derived from indirubin-3-oxime, possesses inhibitory effects against cyclin-dependent kinase-5 (CDK5 and glycogen synthase kinase-3β (GSK3β, two pharmacological targets of Alzheimer's disease (AD. In this study, we have discovered that 2.3–23.3 μg/kg 7Bio effectively prevented β-amyloid (Aβ oligomer-induced impairments of spatial cognition and recognition without affecting bodyweight and motor functions in mice. Moreover, 7Bio potently inhibited Aβ oligomer-induced expression of interleukin-6 (IL-6 and tumor necrosis factor-α (TNF-α. Furthermore, 7Bio significantly prevented the decreased expression of synapsin-1 and PSD-95, biomarkers of pre-synaptic and post-synaptic proteins in Aβ oligomer-treated mice. The mean optical density (OD with hyper-phosphorylated tau (pTau, glial fibrillary acidic protein (GFAP and CD45 positive staining in the hippocampus of 7Bio-treated mice were significantly decreased compared to those of Aβ oligomer-treated mice. In addition, Western blotting analysis showed that 7Bio attenuated Aβ oligomer-decreased expression of pSer9-GSK3β. Those results suggested that 7Bio could potently inhibit Aβ oligomer-induced neuroinflammation, synaptic impairments, tau hyper-phosphorylation, and activation of astrocytes and microglia, which may contribute to the neuroprotective effects of 7Bio. Based on these findings, we expected that 7Bio might be developed as a novel anti-AD lead compound.

Development of central nervous system autoimmunity is impaired in the absence of Wiskott-Aldrich syndrome protein.

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Marita Bosticardo

Full Text Available Wiskott-Aldrich Syndrome protein (WASP is a key regulator of the actin cytoskeleton in hematopoietic cells. Defective expression of WASP leads to multiple abnormalities in different hematopoietic cells. Despite severe impairment of T cell function, WAS patients exhibit a high prevalence of autoimmune disorders. We attempted to induce EAE, an animal model of organ-specific autoimmunity affecting the CNS that mimics human MS, in Was(-/- mice. We describe here that Was(-/- mice are markedly resistant against EAE, showing lower incidence and milder score, reduced CNS inflammation and demyelination as compared to WT mice. Microglia was only poorly activated in Was(-/- mice. Antigen-induced T-cell proliferation, Th-1 and -17 cytokine production and integrin-dependent adhesion were increased in Was(-/- mice. However, adoptive transfer of MOG-activated T cells from Was(-/- mice in WT mice failed to induce EAE. Was(-/- mice were resistant against EAE also when induced by adoptive transfer of MOG-activated T cells from WT mice. Was(+/- heterozygous mice developed an intermediate clinical phenotype between WT and Was(-/- mice, and they displayed a mixed population of WASP-positive and -negative T cells in the periphery but not in their CNS parenchyma, where the large majority of inflammatory cells expressed WASP. In conclusion, in absence of WASP, T-cell responses against a CNS autoantigen are increased, but the ability of autoreactive T cells to induce CNS autoimmunity is impaired, most probably because of an inefficient T-cell transmigration into the CNS and defective CNS resident microglial function.

Obstacle Detection Display for Visually Impaired: Coding of Direction, Distance, and Height on a Vibrotactile Waist Band

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Jan B. F. van Erp

2017-10-01

Full Text Available Electronic travel aids (ETAs can potentially increase the safety and comfort of blind users by detecting and displaying obstacles outside the range of the white cane. In a series of experiments, we aim to balance the amount of information displayed and the comprehensibility of the information taking into account the risk of information overload. In Experiment 1, we investigate perception of compound signals displayed on a tactile vest while walking. The results confirm that the threat of information overload is clear and present. Tactile coding parameters that are sufficiently discriminable in isolation may not be so in compound signals and while walking and using the white cane. Horizontal tactor location is a strong coding parameter, and temporal pattern is the preferred secondary coding parameter. Vertical location is also possible as coding parameter but it requires additional tactors and makes the display hardware more complex and expensive and less user friendly. In Experiment 2, we investigate how we can off-load the tactile modality by mitigating part of the information to an auditory display. Off-loading the tactile modality through auditory presentation is possible, but this off-loading is limited and may result in a new threat of auditory overload. In addition, taxing the auditory channel may in turn interfere with other auditory cues from the environment. In Experiment 3, we off-load the tactile sense by reducing the amount of displayed information using several filter rules. The resulting design was evaluated in Experiment 4 with visually impaired users. Although they acknowledge the potential of the display, the added of the ETA as a whole also depends on its sensor and object recognition capabilities. We recommend to use not more than two coding parameters in a tactile compound message and apply filter rules to reduce the amount of obstacles to be displayed in an obstacle avoidance ETA.

Selective impairment of subcategories of long-term memory in mice with hippocampal lesions accessed by the olfactory tubing maze.

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Chaillan, F A; Marchetti, E; Soumireu-Mourat, B; Roman, F S

2005-03-30

A new apparatus, the olfactory tubing maze for mice, was developed recently to study learning and memory processes in mice in regard to their ethological abilities. As in humans, BALB/c mice with selective bilateral lesions of the hippocampal formation showed selective impairment of subcategories of long-term memory when tested with the olfactory tubing maze. After three learning sessions, control mice reached a high percentage of correct responses. They consistently made the olfactory-reward associations, but antero-dorsal and postero-ventral hippocampal-lesioned mice did not. However, all lesioned mice learned the paradigm and the timing of the task as fast and as well as control mice. These data suggest that the olfactory tubing maze can be used to study subcategories of memory, such as declarative and non-declarative memory, which are similar in some respects to those observed in humans. Consequently, possible memory effects of classical approaches (i.e., pharmacological or lesion studies) or genetic modifications in transgenic or gene-targeting mice can be effectively analyzed using this new apparatus.

Muscarinic supersensitivity and impaired receptor desensitization in G protein-coupled receptor kinase 5-deficient mice.

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Gainetdinov, R R; Bohn, L M; Walker, J K; Laporte, S A; Macrae, A D; Caron, M G; Lefkowitz, R J; Premont, R T

1999-12-01

G protein-coupled receptor kinase 5 (GRK5) is a member of a family of enzymes that phosphorylate activated G protein-coupled receptors (GPCR). To address the physiological importance of GRK5-mediated regulation of GPCRs, mice bearing targeted deletion of the GRK5 gene (GRK5-KO) were generated. GRK5-KO mice exhibited mild spontaneous hypothermia as well as pronounced behavioral supersensitivity upon challenge with the nonselective muscarinic agonist oxotremorine. Classical cholinergic responses such as hypothermia, hypoactivity, tremor, and salivation were enhanced in GRK5-KO animals. The antinociceptive effect of oxotremorine was also potentiated and prolonged. Muscarinic receptors in brains from GRK5-KO mice resisted oxotremorine-induced desensitization, as assessed by oxotremorine-stimulated [5S]GTPgammaS binding. These data demonstrate that elimination of GRK5 results in cholinergic supersensitivity and impaired muscarinic receptor desensitization and suggest that a deficit of GPCR desensitization may be an underlying cause of behavioral supersensitivity.

Impaired cognitive discrimination and discoordination of coupled theta-gamma oscillations in Fmr1 knockout mice

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Radwan, Basma; Dvorak, Dino; Fenton, André

2016-01-01

Fragile X syndrome (FXS) patients do not make the fragile X mental retardation protein (FMRP). Absence of FMRP causes dysregulated translation, abnormal synaptic plasticity and the most common form of inherited intellectual disability. But FMRP loss has minimal effects on memory itself, making it difficult to understand why absence of FMRP impairs memory discrimination and increases risk of autistic symptoms in patients, such as exaggerated responses to environmental changes. While Fmr1 knockout (KO) and wild-type (WT) mice perform cognitive discrimination tasks, we find abnormal patterns of coupling between theta and gamma oscillations in perisomatic and dendritic hippocampal CA1 local field potentials of the KO. Perisomatic CA1 theta-gamma phase-amplitude coupling (PAC) decreases with familiarity in both the WT and KO, but activating an invisible shock zone, subsequently changing its location, or turning it off, changes the pattern of oscillatory events in the LFPs recorded along the somato-dendritic axis of CA1. The cognition-dependent changes of this pattern of neural activity are relatively constrained in WT mice compared to KO mice, which exhibit abnormally weak changes during the cognitive challenge caused by changing the location of the shock zone and exaggerated patterns of change when the shock zone is turned off. Such pathophysiology might explain how dysregulated translation leads to intellectual disability in FXS. These findings demonstrate major functional abnormalities after the loss of FMRP in the dynamics of neural oscillations and that these impairments would be difficult to detect by steady-state measurements with the subject at rest or in steady conditions. PMID:26792400

Clinically relevant doses of lidocaine and bupivacaine do not impair cutaneous wound healing in mice.

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Waite, A; Gilliver, S C; Masterson, G R; Hardman, M J; Ashcroft, G S

2010-06-01

Lidocaine and bupivacaine are commonly infiltrated into surgical cutaneous wounds to provide local anaesthesia after surgical procedures. However, very little is known about their effects on cutaneous wound healing. If an inhibitory effect is demonstrated, then the balance between the benefits of postoperative local anaesthesia and the negatives of impaired cutaneous wound healing may affect the decision to use local anaesthesia or not. Furthermore, if a difference in the rate of healing of lidocaine- and bupivacaine-treated cutaneous wounds is revealed, or if an inhibitory effect is found to be dose-dependent, then this may well influence the choice of agent and its concentration for clinical use. Immediately before incisional wounding, we administered lidocaine and bupivacaine intradermally to adult female mice, some of which had been ovariectomized to act as a model of post-menopausal women (like post-menopausal women, ovariectomized mice heal wounds poorly, with increased proteolysis and inflammation). Day 3 wound tissue was analysed histologically and tested for expression of inflammatory and proteolytic factors. On day 3 post-wounding, wound areas and extent of re-epithelialization were comparable between the control and local anaesthetic-treated animals, in both intact and ovariectomized groups. Both tested drugs significantly increased wound activity of the degradative enzyme matrix metalloproteinase-2 relative to controls, while lidocaine also increased wound neutrophil numbers. Although lidocaine and bupivacaine influenced local inflammatory and proteolytic factors, they did not impair the rate of healing in either of two well-established models (mimicking normal human wound healing and impaired age-related healing).

Protein energy malnutrition impairs homeostatic proliferation of memory CD8 T cells.

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Iyer, Smita S; Chatraw, Janel Hart; Tan, Wendy G; Wherry, E John; Becker, Todd C; Ahmed, Rafi; Kapasi, Zoher F

2012-01-01

Nutrition is a critical but poorly understood determinant of immunity. There is abundant epidemiological evidence linking protein malnutrition to impaired vaccine efficacy and increased susceptibility to infections; yet, the role of dietary protein in immune memory homeostasis remains poorly understood. In this study, we show that protein-energy malnutrition induced in mice by low-protein (LP) feeding has a detrimental impact on CD8 memory. Relative to adequate protein (AP)-fed controls, LP feeding in lymphocytic choriomeningitis virus (LCMV)-immune mice resulted in a 2-fold decrease in LCMV-specific CD8 memory T cells. Adoptive transfer of memory cells, labeled with a division tracking dye, from AP mice into naive LP or AP mice demonstrated that protein-energy malnutrition caused profound defects in homeostatic proliferation. Remarkably, this defect occurred despite the lymphopenic environment in LP hosts. Whereas Ag-specific memory cells in LP and AP hosts were phenotypically similar, memory cells in LP hosts were markedly less responsive to polyinosinic-polycytidylic acid-induced acute proliferative signals. Furthermore, upon recall, memory cells in LP hosts displayed reduced proliferation and protection from challenge with LCMV-clone 13, resulting in impaired viral clearance in the liver. The findings show a metabolic requirement of dietary protein in sustaining functional CD8 memory and suggest that interventions to optimize dietary protein intake may improve vaccine efficacy in malnourished individuals.

LRRK2 knockout mice have an intact dopaminergic system but display alterations in exploratory and motor co-ordination behaviors

Science.gov (United States)

2012-01-01

Mutations in the LRRK2 gene are the most common cause of genetic Parkinson’s disease. Although the mechanisms behind the pathogenic effects of LRRK2 mutations are still not clear, data emerging from in vitro and in vivo models suggests roles in regulating neuronal polarity, neurotransmission, membrane and cytoskeletal dynamics and protein degradation. We created mice lacking exon 41 that encodes the activation hinge of the kinase domain of LRRK2. We have performed a comprehensive analysis of these mice up to 20 months of age, including evaluation of dopamine storage, release, uptake and synthesis, behavioral testing, dendritic spine and proliferation/neurogenesis analysis. Our results show that the dopaminergic system was not functionally comprised in LRRK2 knockout mice. However, LRRK2 knockout mice displayed abnormal exploratory activity in the open-field test. Moreover, LRRK2 knockout mice stayed longer than their wild type littermates on the accelerated rod during rotarod testing. Finally, we confirm that loss of LRRK2 caused degeneration in the kidney, accompanied by a progressive enhancement of autophagic activity and accumulation of autofluorescent material, but without evidence of biphasic changes. PMID:22647713

Tooth loss early in life suppresses neurogenesis and synaptophysin expression in the hippocampus and impairs learning in mice.

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Kubo, Kin-Ya; Murabayashi, Chika; Kotachi, Mika; Suzuki, Ayumi; Mori, Daisuke; Sato, Yuichi; Onozuka, Minoru; Azuma, Kagaku; Iinuma, Mitsuo

2017-02-01

Tooth loss induced neurological alterations through activation of a stress hormone, corticosterone. Age-related hippocampal morphological and functional changes were accelerated by early tooth loss in senescence-accelerated mouse prone 8 (SAMP8). In order to explore the mechanism underlying the impaired hippocampal function resulting from early masticatory dysfunction due to tooth loss, we investigated the effects of early tooth loss on plasma corticosterone levels, learning ability, neurogenesis, and synaptophysin expression in the hippocampus later in life of SAMP8 mice. We examined the effects of tooth loss soon after tooth eruption (1 month of age) on plasma corticosterone levels, learning ability in the Morris water maze, newborn cell proliferation, survival and differentiation in the hippocampal dentate gyrus, and synaptophysin expression in the hippocampus of aged (8 months of age) SAMP8 mice. Aged mice with early tooth loss exhibited increased plasma corticosterone levels, hippocampus-dependent learning deficits in the Morris water maze, decreased cell proliferation, and cell survival in the dentate gyrus, and suppressed synaptophysin expression in the hippocampus. Newborn cell differentiation in the hippocampal dentate gyrus, however, was not affected by early tooth loss. These findings suggest that learning deficits in aged SAMP8 mice with tooth loss soon after tooth eruption are associated with suppressed neurogenesis and decreased synaptophysin expression resulting from increased plasma corticosterone levels, and that long-term tooth loss leads to impaired cognitive function in older age. Copyright © 2016. Published by Elsevier Ltd.

Steamed and Fermented Ethanolic Extract from Codonopsis lanceolata Attenuates Amyloid-β-Induced Memory Impairment in Mice

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Jin Bae Weon

2016-01-01

Full Text Available Codonopsis lanceolata (C. lanceolata is a traditional medicinal plant used for the treatment of certain inflammatory diseases such as asthma, tonsillitis, and pharyngitis. We evaluated whether steamed and fermented C. lanceolata (SFC extract improves amyloid-β- (Aβ- induced learning and memory impairment in mice. The Morris water maze and passive avoidance tests were used to evaluate the effect of SFC extract. Moreover, we investigated acetylcholinesterase (AChE activity and brain-derived neurotrophic factor (BDNF, cyclic AMP response element-binding protein (CREB, and extracellular signal-regulated kinase (ERK signaling in the hippocampus of mice to determine a possible mechanism for the cognitive-enhancing effect. Saponin compounds in SFC were identified by Ultra Performance Liquid Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry (UPLC-Q-TOF-MS. SFC extract ameliorated amyloid-β-induced memory impairment in the Morris water maze and passive avoidance tests. SFC extract inhibited AChE activity and also significantly increased the level of CREB phosphorylation, BDNF expression, and ERK activation in hippocampal tissue of amyloid-β-treated mice. Lancemasides A, B, C, D, E, and G and foetidissimoside A compounds present in SFC were determined by UPLC-Q-TOF-MS. These results indicate that SFC extract improves Aβ-induced memory deficits and that AChE inhibition and CREB/BDNF/ERK expression is important for the effect of the SFC extract. In addition, lancemaside A specifically may be responsible for efficacious effect of SFC.

CALHM1 deficiency impairs cerebral neuron activity and memory flexibility in mice.

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Vingtdeux, Valérie; Chang, Eric H; Frattini, Stephen A; Zhao, Haitian; Chandakkar, Pallavi; Adrien, Leslie; Strohl, Joshua J; Gibson, Elizabeth L; Ohmoto, Makoto; Matsumoto, Ichiro; Huerta, Patricio T; Marambaud, Philippe

2016-04-12

CALHM1 is a cell surface calcium channel expressed in cerebral neurons. CALHM1 function in the brain remains unknown, but recent results showed that neuronal CALHM1 controls intracellular calcium signaling and cell excitability, two mechanisms required for synaptic function. Here, we describe the generation of Calhm1 knockout (Calhm1(-/-)) mice and investigate CALHM1 role in neuronal and cognitive functions. Structural analysis revealed that Calhm1(-/-) brains had normal regional and cellular architecture, and showed no evidence of neuronal or synaptic loss, indicating that CALHM1 deficiency does not affect brain development or brain integrity in adulthood. However, Calhm1(-/-) mice showed a severe impairment in memory flexibility, assessed in the Morris water maze, and a significant disruption of long-term potentiation without alteration of long-term depression, measured in ex vivo hippocampal slices. Importantly, in primary neurons and hippocampal slices, CALHM1 activation facilitated the phosphorylation of NMDA and AMPA receptors by protein kinase A. Furthermore, neuronal CALHM1 activation potentiated the effect of glutamate on the expression of c-Fos and C/EBPβ, two immediate-early gene markers of neuronal activity. Thus, CALHM1 controls synaptic activity in cerebral neurons and is required for the flexible processing of memory in mice. These results shed light on CALHM1 physiology in the mammalian brain.

Long-term activation of TLR3 by Poly(I:C induces inflammation and impairs lung function in mice

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Alexopoulou Lena

2009-06-01

Full Text Available Abstract Background The immune mechanisms associated with infection-induced disease exacerbations in asthma and COPD are not fully understood. Toll-like receptor (TLR 3 has an important role in recognition of double-stranded viral RNA, which leads to the production of various inflammatory mediators. Thus, an understanding of TLR3 activation should provide insight into the mechanisms underlying virus-induced exacerbations of pulmonary diseases. Methods TLR3 knock-out (KO mice and C57B6 (WT mice were intranasally administered repeated doses of the synthetic double stranded RNA analog poly(I:C. Results There was a significant increase in total cells, especially neutrophils, in BALF samples from poly(I:C-treated mice. In addition, IL-6, CXCL10, JE, KC, mGCSF, CCL3, CCL5, and TNFα were up regulated. Histological analyses of the lungs revealed a cellular infiltrate in the interstitium and epithelial cell hypertrophy in small bronchioles. Associated with the pro-inflammatory effects of poly(I:C, the mice exhibited significant impairment of lung function both at baseline and in response to methacholine challenge as measured by whole body plethysmography and an invasive measure of airway resistance. Importantly, TLR3 KO mice were protected from poly(I:C-induced changes in lung function at baseline, which correlated with milder inflammation in the lung, and significantly reduced epithelial cell hypertrophy. Conclusion These findings demonstrate that TLR3 activation by poly(I:C modulates the local inflammatory response in the lung and suggest a critical role of TLR3 activation in driving lung function impairment. Thus, TLR3 activation may be one mechanism through which viral infections contribute toward exacerbation of respiratory disease.

High-fat feeding impairs nutrient sensing and gut brain integration in the caudomedial nucleus of the solitary tract in mice.

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Althea R Cavanaugh

Full Text Available Hyperphagic obesity is characterized in part by a specific increase in meal size that contributes to increased daily energy intake, but the mechanisms underlying impaired activity of meal size regulatory circuits, particularly those converging at the caudomedial nucleus of the solitary tract in the hindbrain (cmNTS, remain poorly understood. In this paper, we assessed the consequences of high-fat (HF feeding and diet-induced obesity (DIO on cmNTS nutrient sensing and metabolic integration in the control of meal size. Mice maintained on a standard chow diet, low-fat (LF diet or HF diet for 2 weeks or 6 months were implanted with a bilateral brain cannula targeting the cmNTS. Feeding behavior was assessed using behavioral chambers and meal-pattern analysis following cmNTS L-leucine injections alone or together with ip CCK. Molecular mechanisms implicated in the feeding responses were assessed using western blot, immunofluorescence and pharmacological inhibition of the amino acid sensing mTORC1 pathway (mammalian target of rapamycin complex 1. We found that HF feeding blunts the anorectic consequences of cmNTS L-leucine administration. Increased baseline activity of the L-leucine sensor P70 S6 kinase 1 and impaired L-leucine-induced activation of this pathway in the cmNTS of HF-fed mice indicate that HF feeding is associated with an impairment in cmNTS mTOR nutritional and hormonal sensing. Interestingly, the acute orexigenic effect of the mTORC1 inhibitor rapamycin was preserved in HF-fed mice, supporting the assertion that HF-induced increase in baseline cmNTS mTORC1 activity underlies the defect in L-leucine sensing. Last, the synergistic feeding-suppressive effect of CCK and cmNTS L-leucine was abrogated in DIO mice. These results indicate that HF feeding leads to an impairment in cmNTS nutrient sensing and metabolic integration in the regulation of meal size.

12/15-Lipoxygenase Inhibition Reverses Cognitive Impairment, Brain Amyloidosis, and Tau Pathology by Stimulating Autophagy in Aged Triple Transgenic Mice.

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Di Meco, Antonio; Li, Jian-Guo; Blass, Benjamin E; Abou-Gharbia, Magid; Lauretti, Elisabetta; Praticò, Domenico

2017-01-15

The 12/15-lipoxygenase (12/15-LO) enzyme is upregulated in the brains of patients with Alzheimer's disease (AD), and its expression levels influence the onset of the AD-like phenotype in mouse models. However, whether targeting this pathway after the neuropathology and behavioral impairments have been established remains to be investigated. Triple transgenic (3xTg) mice received either PD146176-a selective and specific pharmacological inhibitor of 12/15-LO-or placebo starting at 12 months of age for 12 weeks. They were then assessed for the effect of the treatment on neuropathologies and behavioral impairments. At the end of the study, mice in the control group showed a worsening of memory and learning abilities, whereas mice receiving PD146176 were undistinguishable from wild-type mice. The same group also had significantly lower amyloid beta levels and deposition, less tau neuropathology, increased synaptic integrity, and autophagy activation. Ex vivo and in vitro genetic and pharmacological studies found that the mechanism involved in these effects was the activation of neuronal autophagy. Our findings provide new insights into the disease-modifying action of 12/15-LO pharmacological inhibition and establish it as a viable therapeutic approach for patients with AD. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Effect of Ginseng (Panax ginseng Berry EtOAc Fraction on Cognitive Impairment in C57BL/6 Mice under High-Fat Diet Inducement

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Chang Hyeon Park

2015-01-01

Full Text Available High-fat diet-induced obesity leads to type 2 diabetes. Recently, there has been growing apprehension about diabetes-associated cognitive impairment (DACM. The effect of ginseng (Panax ginseng berry ethyl acetate fraction (GBEF on mice with high-fat diet-induced cognitive impairment was investigated to confirm its physiological function. C57BL/6 mice were fed a high-fat diet for 5 weeks and then a high-fat diet with GBEF (20 and 50 mg/kg of body weight for 4 weeks. After three in vivo behavioral tests (Y-maze, passive avoidance, and Morris water maze tests, blood samples were collected from the postcaval vein for biochemical analysis, and whole brains were prepared for an ex vivo test. A method based on ultra-performance liquid chromatography (UPLC accurate-mass quadrupole time-of-flight mass spectrometry (Q-TOF/MS was used to determine major ginsenosides. GBEF decreased the fasting blood glucose levels of high-fat diet-induced diabetes mellitus (DM mice and improved hyperglycemia. Cognitive behavior tests were examined after setting up the DM mice. The in vivo experiments showed that mice treated with GBEF exhibited more improved cognitive behavior than DM mice. In addition, GBEF effectively inhibited the acetylcholinesterase (AChE activity and malondialdehyde (MDA levels of DM mice brain tissues. Q-TOF UPLC/MS analyses of GBEF showed that ginsenoside Re was the major ginsenoside.

Impaired intestinal wound healing in Fhl2-deficient mice is due to disturbed collagen metabolism

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Kirfel, Jutta; Pantelis, Dimitrios; Kabba, Mustapha; Kahl, Philip; Roeper, Anke; Kalff, Joerg C.; Buettner, Reinhard

2008-01-01

Four and one half LIM domain protein FHL2 participates in many cellular processes involved in tissue repair such as regulation of gene expression, cytoarchitecture, cell adhesion, migration and signal transduction. The repair process after wounding is initiated by the release of peptides and bioactive lipids. These molecules induce synthesis and deposition of a provisional extracellular matrix. We showed previously that sphingosine-1-phosphate (S1P) triggers a signal transduction cascade mediating nuclear translocation of FHL2 in response to activation of the RhoA GTPase. Our present study shows that FHL2 is an important signal transducer influencing the outcome of intestinal anastomotic healing. Early wound healing is accompanied by reconstitution and remodelling of the extracellular matrix and collagen is primarily responsible for wound strength. Our results show that impaired intestinal wound healing in Fhl2-deficient mice is due to disturbed collagen III metabolism. Impaired collagen III synthesis reduced the mechanical stability of the anastomoses and led to lower bursting pressure in Fhl2-deficient mice after surgery. Our data confirm that FHL2 is an important factor regulating collagen expression in the early phase of wound healing, and thereby is critically involved in the physiologic process of anastomosis healing after bowel surgery and thus may represent a new therapeutic target

Aqueous and hydroalcoholic extracts of Black Maca (Lepidium meyenii) improve scopolamine-induced memory impairment in mice.

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Rubio, Julio; Dang, Haixia; Gong, Mengjuan; Liu, Xinmin; Chen, Shi-Lin; Gonzales, Gustavo F

2007-10-01

Lepidium meyenii Walp. (Brassicaceae), known as Maca, is a Peruvian hypocotyl growing exclusively between 4,000 and 4,500 m altitude in the central Peruvian Andes, particularly in Junin plateau. Previously, Black variety of Maca showed to be more beneficial than other varieties of Maca on learning and memory in ovariectomized mice on the water finding test. The present study aimed to test two different doses of aqueous (0.50 and 2.00 g/kg) and hydroalcoholic (0.25 and 1.00 g/kg) extracts of Black Maca administered for 35 days on memory impairment induced by scopolamine (1mg/kg body weight i.p.) in male mice. Memory and learning were evaluated using the water Morris maze and the step-down avoidance test. Brain acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities in brain were also determined. Both extracts of Black Maca significantly ameliorated the scopolamine-induced memory impairment as measured in both the water Morris maze and the step-down avoidance tests. Black Maca extracts inhibited AChE activity, whereas MAO activity was not affected. These results indicate that Black Maca improves scopolamine-induced memory deficits.

Abnormal social behavior, hyperactivity, impaired remote spatial memory, and increased D1-mediated dopaminergic signaling in neuronal nitric oxide synthase knockout mice

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Tanda Koichi

2009-06-01

Full Text Available Abstract Background Neuronal nitric oxide synthase (nNOS is involved in the regulation of a diverse population of intracellular messenger systems in the brain. In humans, abnormal NOS/nitric oxide metabolism is suggested to contribute to the pathogenesis and pathophysiology of some neuropsychiatric disorders, such as schizophrenia and bipolar disorder. Mice with targeted disruption of the nNOS gene exhibit abnormal behaviors. Here, we subjected nNOS knockout (KO mice to a battery of behavioral tests to further investigate the role of nNOS in neuropsychiatric functions. We also examined the role of nNOS in dopamine/DARPP-32 signaling in striatal slices from nNOS KO mice and the effects of the administration of a dopamine D1 receptor agonist on behavior in nNOS KO mice. Results nNOS KO mice showed hyperlocomotor activity in a novel environment, increased social interaction in their home cage, decreased depression-related behavior, and impaired spatial memory retention. In striatal slices from nNOS KO mice, the effects of a dopamine D1 receptor agonist, SKF81297, on the phosphorylation of DARPP-32 and AMPA receptor subunit GluR1 at protein kinase A sites were enhanced. Consistent with the biochemical results, intraperitoneal injection of a low dose of SKF81297 significantly decreased prepulse inhibition in nNOS KO mice, but not in wild-type mice. Conclusion These findings indicate that nNOS KO upregulates dopamine D1 receptor signaling, and induces abnormal social behavior, hyperactivity and impaired remote spatial memory. nNOS KO mice may serve as a unique animal model of psychiatric disorders.

Maternal obesity reduces milk lipid production in lactating mice by inhibiting acetyl-CoA carboxylase and impairing fatty acid synthesis.

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Saben, Jessica L; Bales, Elise S; Jackman, Matthew R; Orlicky, David; MacLean, Paul S; McManaman, James L

2014-01-01

Maternal metabolic and nutrient trafficking adaptations to lactation differ among lean and obese mice fed a high fat (HF) diet. Obesity is thought to impair milk lipid production, in part, by decreasing trafficking of dietary and de novo synthesized lipids to the mammary gland. Here, we report that de novo lipogenesis regulatory mechanisms are disrupted in mammary glands of lactating HF-fed obese (HF-Ob) mice. HF feeding decreased the total levels of acetyl-CoA carboxylase-1 (ACC), and this effect was exacerbated in obese mice. The relative levels of phosphorylated (inactive) ACC, were elevated in the epithelium, and decreased in the adipose stroma, of mammary tissue from HF-Ob mice compared to those of HF-fed lean (HF-Ln) mice. Mammary gland levels of AMP-activated protein kinase (AMPK), which catalyzes formation of inactive ACC, were also selectively elevated in mammary glands of HF-Ob relative to HF-Ln dams or to low fat fed dams. These responses correlated with evidence of increased lipid retention in mammary adipose, and decreased lipid levels in mammary epithelial cells, of HF-Ob dams. Collectively, our data suggests that maternal obesity impairs milk lipid production, in part, by disrupting the balance of de novo lipid synthesis in the epithelial and adipose stromal compartments of mammary tissue through processes that appear to be related to increased mammary gland AMPK activity, ACC inhibition, and decreased fatty acid synthesis.

cGMP-dependent protein kinase type II knockout mice exhibit working memory impairments, decreased repetitive behavior, and increased anxiety-like traits.

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Wincott, Charlotte M; Abera, Sinedu; Vunck, Sarah A; Tirko, Natasha; Choi, Yoon; Titcombe, Roseann F; Antoine, Shannon O; Tukey, David S; DeVito, Loren M; Hofmann, Franz; Hoeffer, Charles A; Ziff, Edward B

2014-10-01

Neuronal activity regulates AMPA receptor trafficking, a process that mediates changes in synaptic strength, a key component of learning and memory. This form of plasticity may be induced by stimulation of the NMDA receptor which, among its activities, increases cyclic guanosine monophosphate (cGMP) through the nitric oxide synthase pathway. cGMP-dependent protein kinase type II (cGKII) is ultimately activated via this mechanism and AMPA receptor subunit GluA1 is phosphorylated at serine 845. This phosphorylation contributes to the delivery of GluA1 to the synapse, a step that increases synaptic strength. Previous studies have shown that cGKII-deficient mice display striking spatial learning deficits in the Morris Water Maze compared to wild-type littermates as well as lowered GluA1 phosphorylation in the postsynaptic density of the prefrontal cortex (Serulle et al., 2007; Wincott et al., 2013). In the current study, we show that cGKII knockout mice exhibit impaired working memory as determined using the prefrontal cortex-dependent Radial Arm Maze (RAM). Additionally, we report reduced repetitive behavior in the Marble Burying task (MB), and heightened anxiety-like traits in the Novelty Suppressed Feeding Test (NSFT). These data suggest that cGKII may play a role in the integration of information that conveys both anxiety-provoking stimuli as well as the spatial and environmental cues that facilitate functional memory processes and appropriate behavioral response. Published by Elsevier Inc.

1Protein Energy Malnutrition Impairs Homeostatic Proliferation of Memory CD8 T cells

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Iyer, Smita S.; Chatraw, Janel Hart; Tan, Wendy G.; Wherry, E. John; Becker, Todd C.; Ahmed, Rafi; Kapasi, Zoher F.

2011-01-01

Nutrition is a critical but poorly understood determinant of immunity. There is abundant epidemiological evidence linking protein malnutrition to impaired vaccine efficacy and increased susceptibility to infections; yet, the role of dietary protein in immune memory homeostasis remains poorly understood. Here we show that protein energy malnutrition (PEM) induced in mice by low-protein (LP) feeding has a detrimental impact on CD8 memory. Relative to adequate-protein (AP) fed controls, LP feeding in lymphocytic choriomeningitis virus (LCMV) immune mice resulted in a 2-fold decrease in LCMV-specific CD8 memory T cells. Adoptive transfer of memory cells, labeled with a division tracking dye, from AP mice into naive LP or AP mice demonstrated that PEM caused profound defects in homeostatic proliferation. Remarkably, this defect occurred despite the lymphopenic environment in LP hosts. While antigen-specific memory cells in LP and AP hosts were phenotypically similar, memory cells in LP hosts were markedly less-responsive to poly(I:C)-induced acute proliferative signals. Furthermore, upon recall, memory cells in LP hosts displayed reduced proliferation and protection from challenge with LCMV-clone 13 resulting in impaired viral clearance in the liver. The findings show a metabolic requirement of dietary protein in sustaining functional CD8 memory and suggest that interventions to optimize dietary protein intake may improve vaccine efficacy in malnourished individuals. PMID:22116826

Role of light and the circadian clock in the rhythmic oscillation of intraocular pressure: Studies in VPAC2 receptor and PACAP deficient mice.

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Fahrenkrug, Jan; Georg, Birgitte; Hannibal, Jens; Jørgensen, Henrik Løvendahl

2018-04-01

The intraocular pressure of mice displays a daily rhythmicity being highest during the dark period. The present study was performed to elucidate the role of the circadian clock and light in the diurnal and the circadian variations in intraocular pressure in mice, by using animals with disrupted clock function (VPAC2 receptor knockout mice) or impaired light information to the clock (PACAP knockout mice). In wildtype mice, intraocular pressure measured under light/dark conditions showed a statistically significant 24 h sinusoidal rhythm with nadir during the light phase and peak during the dark phase. After transfer of the wildtype mice into constant darkness, the intraocular pressure increased, but the rhythmic changes in intraocular pressure continued with a pattern identical to that obtained during the light/dark cycle. The intraocular pressure in VPAC2 receptor deficient mice during light/dark conditions also showed a sinusoidal pattern with significant changes as a function of a 24 h cycle. However, transfer of the VPAC2 receptor knockout mice into constant darkness completely abolished the rhythmic changes in intraocular pressure. The intraocular pressure in PACAP deficient mice oscillated significantly during both 24 h light and darkness and during constant darkness. During LD conditions, the amplitude of PACAP deficient was significantly lower compared to wildtype mice, resulting in higher daytime and lower nighttime values. In conclusion, by studying the VPAC2 receptor knockout mouse which lacks circadian control and the PACAP knockout mouse which displays impaired light signaling, we provided evidence that the daily intraocular pressure rhythms are primarily generated by the circadian master clock and to a lesser extent by environmental light and darkness. Copyright © 2018 Elsevier Ltd. All rights reserved.

Deoxyschizandrin isolated from the fruits of Schisandra chinensis ameliorates Aβ₁₋₄₂-induced memory impairment in mice.

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Hu, Di; Li, Changxia; Han, Na; Miao, Lijing; Wang, Dong; Liu, Zhihui; Wang, Hua; Yin, Jun

2012-08-01

In the present study, we examined the effects of deoxyschisandrin (DS) from Schisandra chinensis on the amyloid-beta₁₋₄₂ (Aβ₁₋₄₂)-induced memory impairment in mice and investigated the possible antioxidative mechanism. Mice were given an intracerebroventricular (i. c. v.) injection with the aggregated Aβ₁₋₄₂ and then treated with DS (4, 12, and 36 mg/kg body weight) or donepezil (DPZ), a positive control drug (0.65 mg/kg), by intragastric infusion for 14 days. Non-cognitive disturbances and cognitive performance were evaluated by the locomotor activity, Y-maze, and water maze tests. Antioxidative enzyme activities including superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) and levels of malondialdehyde (MDA), glutathione (GSH), and oxidized glutathione (GSSG) within the cerebral cortex and hippocampus of mice were measured to investigate the mechanism. Our results showed that DS significantly improved Aβ₁₋₄₂-induced short-term and spatial memory impairments in the Y-maze and water maze tests. Furthermore, in the cerebral cortex and hippocampus of mice, the reduced activities of SOD and GSH-px, the GSH level, and the GSH/GSSG ratio were increased, and increased levels of MDA and GSSG were reduced following treatment with DS, although the improvement of GSH and the reduction of GSSG levels were not marked. These results suggest that DS is a potential cognitive enhancer in Alzheimer's disease through its antioxidative action. Georg Thieme Verlag KG Stuttgart · New York.

Behavioral assessments of BTBR T+Itpr3tf/J mice by tests of object attention and elevated open platform: Implications for an animal model of psychiatric comorbidity in autism.

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Chao, Owen Y; Yunger, Richelle; Yang, Yi-Mei

2018-07-16

Autism spectrum disorders (ASD) are diagnosed based on the behavioral criteria of impaired social interaction, defective communication and repetitive behaviors. Psychiatric comorbidities, such as anxiety and intellectual disability, are commonly present in ASD. The BTBR T+ Itpr3tf/J (BTBR) mice display a range of autistic phenotypes, yet whether this mouse model is appropriate to study psychiatric comorbidity in ASD remains unclear. We addressed this issue by subjecting the BTBR animals to three-chambered apparatus, open field, object attention test and elevated open platform. Compared to C57BL/6J control mice, the BTBR mice displayed hyperactivity in most of the tests. In the three-chamber assessment, they exhibited deficits in sociability. In the open field, more grooming and thigmotaxis and less rearing behaviors were observed. They also showed impaired object-based attention. On the elevated open platform, the BTBR animals stayed more to the edges than in the center of the platform. To further examine the properties of this test, naïve C57BL/6J mice were randomly administrated with saline or an anxiogenic substance, caffeine. The caffeine group demonstrated a similar behavioral pattern as the BTBR mice. When the saline group was re-exposed to the same platform, the time they stayed in the center substantially increased, likely due to reduced anxiety by habituation. These results indicate that the BTBR were more anxious than control mice on the open platform. Taken together, the BTBR strain exhibit emotional and cognitive impairments in addition to autistic behaviors, suggesting that they can be a valid model for ASD with psychiatric comorbidity. Copyright © 2018 Elsevier B.V. All rights reserved.

Signal pathway of hippocampal apoptosis and cognitive impairment of mice caused by cerium chloride.

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Cheng, Zhe; Li, Na; Cheng, Jie; Hu, Renping; Gao, Guodong; Cui, Yaling; Gong, Xiaolan; Wang, Ling; Hong, Fashui

2012-12-01

Experimental studies have demonstrated that lanthanides could impair cognitive functions of children and animals, but very little is known about the hippocampal apoptosis and its molecular mechanism. The study investigated the signal pathway of hippocampal apoptosis induced by intragastric administration of CeCl(3) for 60 consecutive days. It showed that cerium had been significantly accumulated in the mouse hippocampus, and CeCl(3) caused hippocampal apoptosis and impairment of spatial recognition memory of mice. CeCl(3) effectively activated caspase-3 and -9, inhibited Bcl-2, and increased the levels of Bax and cytochrome c, promoted accumulation of reactive oxygen species in the mouse hippocampus. It implied that CeCl(3)-induced apoptosis in the mouse hippocampus could be triggered via mitochondrion-mediated pathway. Our findings suggest the need for great caution to handle the lanthanides for workers and consumers. 2011 Wiley Periodicals, Inc

Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/−-IRS-1+/− Double Heterozygous (IR-IRS1dh Mice

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Andras Franko

2017-05-01

Full Text Available Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR+/−-insulin receptor substrate-1 (IRS-1+/− double heterozygous (IR-IRS1dh mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver.

Impairment of the vascular relaxation and differential expression of caveolin-1 of the aorta of diabetic +db/+db mice.

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Lam, Tze Yan; Seto, Sai Wang; Lau, Yee Man; Au, Lai Shan; Kwan, Yiu Wa; Ngai, Sai Ming; Tsui, Kwong Wing

2006-09-28

In this study, we compared the endothelium-dependent and -independent relaxation of the isolated thoracic aorta of control (+db/+m) and diabetic (+db/+db) (C57BL/KsJ) mice. The gene expression (mRNA and protein) level of the muscarinic M(3) receptors, endothelial nitric oxide synthase (eNOS) and caveolin-1 of the aorta was also evaluated. Acetylcholine caused a concentration-dependent, N(G)-nitro-L-arginine methyl-ester (20 microM)-sensitive relaxation, with approximately 100% relaxation at 10 microM, in +db/+m mice. In +db/+db mice, the acetylcholine-induced relaxation was significantly smaller (maximum relaxation: approximately 80%). The sodium nitroprusside-mediated relaxation was slightly diminished in +db/+db mice, compared to +db/+m mice. However, there was no significant difference in the isoprenaline- and cromakalim-induced relaxation observed in both species. The mRNA and protein expression levels of caveolin-1 were significantly higher in the aorta of +db/+db mice. In contrast, there was no difference in the mRNA and protein expression levels of eNOS and muscarinic M(3) receptors between these mice. Our results demonstrate that the impairment of the acetylcholine-induced, endothelium-dependent aortic relaxation observed in +db/+db mice was probably associated with an enhanced expression of caveolin-1 mRNA and protein.

The Ameliorating Effect of Steamed and Fermented Codonopsis lanceolata on Scopolamine-Induced Memory Impairment in Mice

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Jin Bae Weon

2013-01-01

Full Text Available Codonopsis lanceolata (Campanulaceae have been traditionally used to treat lung inflammatory diseases, such as asthma, tonsillitis, and pharyngitis. The present study was performed to evaluate the cognitive-enhancing effects of steamed and fermented C. lanceolata in scopolamine-induced memory impairments in mice. Cognitive abilities were determined by the Morris water maze and passive avoidance tests. Mice orally received fermented C. lanceolata extract at doses of 100, 300, or 500 mg/kg body weight. Fermented C. lanceolata extract (500 mg/kg body weight, p.o. significantly shortened the escape latency times that were increased by scopolamine on the 4th day of trial sessions in the Morris water maze task. In addition, it exerted longer step-through latency times than those of the scopolamine-treated group in the passive avoidance test. Furthermore, the neuroprotective effects of fermented C. lanceolata extract on glutamate-induced neurocytotoxicity were investigated in HT22 cells. Fermented C. lanceolata extract showed a relative protection ratio of 59.62% at 500 μg/mL. In conclusion, fermented C. lanceolata extract ameliorated scopolamine-induced memory impairments, exerted neuroprotective effects, and improved activity compared to that found with original C. lanceolata. Further study will be required to investigate the mechanisms underlying this cognitive-enhancing activity.

The Mass1frings mutation underlies early onset hearing impairment in BUB/BnJ mice, a model for the auditory pathology of Usher syndrome IIC

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Johnson, K.R.; Zheng, Q.Y.; Weston, M.D.; Ptacek, L.J.; Noben-Trauth, K.

2010-01-01

The human ortholog of the gene responsible for audiogenic seizure susceptibility in Frings and BUB/BnJ mice (mouse gene symbol Mass1) recently was shown to underlie Usher syndrome type IIC (USH2C). Here we report that the Mass1frings mutation is responsible for the early onset hearing impairment of BUB/BnJ mice. We found highly significant linkage of Mass1 with ABR threshold variation among mice from two backcrosses involving BUB/BnJ mice with mice of strains CAST/EiJ and MOLD/RkJ. We also show an additive effect of the Cdh23 locus in modulating the progression of hearing loss in backcross mice. Together, these two loci account for more than 70% of the total ABR threshold variation among the backcross mice at all ages. The modifying effect of the strain-specific Cdh23ahl variant may account for the hearing and audiogenic seizure differences observed between Frings and BUB/BnJ mice, which share the Mass1frings mutation. During postnatal cochlear development in BUB/BnJ mice, stereocilia bundles develop abnormally and remain immature and splayed into adulthood, corresponding with the early onset hearing impairment associated with Mass1frings. Progressive base–apex hair cell degeneration occurs at older ages, corresponding with the age-related hearing loss associated with Cdh23ahl. The molecular basis and pathophysiology of hearing loss suggest BUB/BnJ and Frings mice as models to study cellular and molecular mechanisms underlying USH2C auditory pathology. PMID:15820310

Short-Term Treatment with Bisphenol-A Leads to Metabolic Abnormalities in Adult Male Mice

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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

Impaired liver regeneration is associated with reduced cyclin B1 in natural killer T cell-deficient mice.

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Ben Ya'acov, Ami; Meir, Hadar; Zolotaryova, Lydia; Ilan, Yaron; Shteyer, Eyal

2017-03-23

It has been shown that the proportion of natural killer T cells is markedly elevated during liver regeneration and their activation under different conditions can modulate this process. As natural killer T cells and liver injury are central in liver regeneration, elucidating their role is important. The aim of the current study is to explore the role of natural killer T cells in impaired liver regeneration. Concanvalin A was injected 4 days before partial hepatectomy to natural killer T cells- deficient mice or to anti CD1d1-treated mice. Ki-67 and proliferating cell nuclear antigen were used to measure hepatocytes proliferation. Expression of hepatic cyclin B1 and proliferating cell nuclear antigen were evaluated by Western Blot and liver injury was assessed by ALT and histology. Natural killer T cells- deficient or mice injected with anti CD1d antibodies exhibited reduced liver regeneration. These mice were considerably resistant to ConA-induced liver injury. In the absence of NKT cells hepatic proliferating cell nuclear antigen and cyclin B1 decreased in mice injected with Concanvalin A before partial hepatectomy. This was accompanied with reduced serum interleukin-6 levels. Natural killer T cells play an important role in liver regeneration, which is associated with cyclin B1 and interleukin-6.

Exercise training in Tgαq*44 mice during the progression of chronic heart failure: cardiac vs. peripheral (soleus muscle) impairments to oxidative metabolism.

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Grassi, Bruno; Majerczak, Joanna; Bardi, Eleonora; Buso, Alessia; Comelli, Marina; Chlopicki, Stefan; Guzik, Magdalena; Mavelli, Irene; Nieckarz, Zenon; Salvadego, Desy; Tyrankiewicz, Urszula; Skórka, Tomasz; Bottinelli, Roberto; Zoladz, Jerzy A; Pellegrino, Maria Antonietta

2017-08-01

Cardiac function, skeletal (soleus) muscle oxidative metabolism, and the effects of exercise training were evaluated in a transgenic murine model (Tgα q *44) of chronic heart failure during the critical period between the occurrence of an impairment of cardiac function and the stage at which overt cardiac failure ensues (i.e., from 10 to 12 mo of age). Forty-eight Tgα q *44 mice and 43 wild-type FVB controls were randomly assigned to control groups and to groups undergoing 2 mo of intense exercise training (spontaneous running on an instrumented wheel). In mice evaluated at the beginning and at the end of training we determined: exercise performance (mean distance covered daily on the wheel); cardiac function in vivo (by magnetic resonance imaging); soleus mitochondrial respiration ex vivo (by high-resolution respirometry); muscle phenotype [myosin heavy chain (MHC) isoform content; citrate synthase (CS) activity]; and variables related to the energy status of muscle fibers [ratio of phosphorylated 5'-AMP-activated protein kinase (AMPK) to unphosphorylated AMPK] and mitochondrial biogenesis and function [peroxisome proliferative-activated receptor-γ coactivator-α (PGC-1α)]. In the untrained Tgα q *44 mice functional impairments of exercise performance, cardiac function, and soleus muscle mitochondrial respiration were observed. The impairment of mitochondrial respiration was related to the function of complex I of the respiratory chain, and it was not associated with differences in CS activity, MHC isoforms, p-AMPK/AMPK, and PGC-1α levels. Exercise training improved exercise performance and cardiac function, but it did not affect mitochondrial respiration, even in the presence of an increased percentage of type 1 MHC isoforms. Factors "upstream" of mitochondria were likely mainly responsible for the improved exercise performance. NEW & NOTEWORTHY Functional impairments in exercise performance, cardiac function, and soleus muscle mitochondrial respiration

Hearts of dystonia musculorum mice display normal morphological and histological features but show signs of cardiac stress.

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Justin G Boyer

2010-03-01

Full Text Available Dystonin is a giant cytoskeletal protein belonging to the plakin protein family and is believed to crosslink the major filament systems in contractile cells. Previous work has demonstrated skeletal muscle defects in dystonin-deficient dystonia musculorum (dt mice. In this study, we show that the dystonin muscle isoform is localized at the Z-disc, the H zone, the sarcolemma and intercalated discs in cardiac tissue. Based on this localization pattern, we tested whether dystonin-deficiency leads to structural defects in cardiac muscle. Desmin intermediate filament, microfilament, and microtubule subcellular organization appeared normal in dt hearts. Nevertheless, increased transcript levels of atrial natriuretic factor (ANF, 66% beta-myosin heavy chain (beta-MHC, 95% and decreased levels of sarcoplasmic reticulum calcium pump isoform 2A (SERCA2a, 26%, all signs of cardiac muscle stress, were noted in dt hearts. Hearts from two-week old dt mice were assessed for the presence of morphological and histological alterations. Heart to body weight ratios as well as left ventricular wall thickness and left chamber volume measurements were similar between dt and wild-type control mice. Hearts from dt mice also displayed no signs of fibrosis or calcification. Taken together, our data provide new insights into the intricate structure of the sarcomere by situating dystonin in cardiac muscle fibers and suggest that dystonin does not significantly influence the structural organization of cardiac muscle fibers during early postnatal development.

Intermittent Hypoxia Impairs Glucose Homeostasis in C57BL6/J Mice: Partial Improvement with Cessation of the Exposure

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Polak, Jan; Shimoda, Larissa A.; Drager, Luciano F.; Undem, Clark; McHugh, Holly; Polotsky, Vsevolod Y.; Punjabi, Naresh M.

2013-01-01

Objectives: Obstructive sleep apnea is associated with insulin resistance, glucose intolerance, and type 2 diabetes mellitus. Although several studies have suggested that intermittent hypoxia in obstructive sleep apnea may induce abnormalities in glucose homeostasis, it remains to be determined whether these abnormalities improve after discontinuation of the exposure. The objective of this study was to delineate the effects of intermittent hypoxia on glucose homeostasis, beta cell function, and liver glucose metabolism and to investigate whether the impairments improve after the hypoxic exposure is discontinued. Interventions: C57BL6/J mice were exposed to 14 days of intermittent hypoxia, 14 days of intermittent air, or 7 days of intermittent hypoxia followed by 7 days of intermittent air (recovery paradigm). Glucose and insulin tolerance tests were performed to estimate whole-body insulin sensitivity and calculate measures of beta cell function. Oxidative stress in pancreatic tissue and glucose output from isolated hepatocytes were also assessed. Results: Intermittent hypoxia increased fasting glucose levels and worsened glucose tolerance by 67% and 27%, respectively. Furthermore, intermittent hypoxia exposure was associated with impairments in insulin sensitivity and beta cell function, an increase in liver glycogen, higher hepatocyte glucose output, and an increase in oxidative stress in the pancreas. While fasting glucose levels and hepatic glucose output normalized after discontinuation of the hypoxic exposure, glucose intolerance, insulin resistance, and impairments in beta cell function persisted. Conclusions: Intermittent hypoxia induces insulin resistance, impairs beta cell function, enhances hepatocyte glucose output, and increases oxidative stress in the pancreas. Cessation of the hypoxic exposure does not fully reverse the observed changes in glucose metabolism. Citation: Polak J; Shimoda LA; Drager LF; Undem C; McHugh H; Polotsky VY; Punjabi NM

Ethyl acetate fraction from Hibiscus sabdariffa L. attenuates diabetes-associated cognitive impairment in mice.

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Seung, Tae Wan; Park, Seon Kyeong; Kang, Jin Yong; Kim, Jong Min; Park, Sang Hyun; Kwon, Bong Seok; Lee, Chang Jun; Kang, Jeong Eun; Kim, Dae Ok; Lee, Uk; Heo, Ho Jin

2018-03-01

The ameliorating effects of the ethyl acetate fraction from Hibiscus sabdariffa L. (EFHS) 2 against diabetes mellitus (DM) 3 and DM-induced cognitive impairment were investigated on streptozotocin (STZ) 4 -induced DM mice. The EFHS groups showed improved hyperglycemia and glucose tolerance compared to the STZ group. Furthermore, their liver and kidney function and lipid metabolic imbalance in the blood serum were effectively recovered. The EFHS groups significantly ameliorated STZ-induced cognitive impairment in Y-maze, passive avoidance, and Morris water maze (MWM) 5 tests. The EFHS groups showed significant improvement in the antioxidant and cholinergic systems of the brain tissue. In addition, EFHS had an excellent ameliorating effect on protein expression levels from the tau hyperphosphorylation pathways, such as phospho-c-Jun N-terminal kinases (p-JNK), 6 phospho-tau (p-tau), 7 and cleaved poly (ADP-ribose) polymerase (c-PARP). 8 The main compounds of EFHS were identified as various phenolic compounds, including hibiscus acid, caffeoylquinic acid (CQA) 9 isomers, and quercetin derivates. Therefore, EFHS containing various physiologically active materials can potentially be used for improving DM-induced cognitive impairment via its antioxidant activity, improvement of the cholinergic system, and hyperphosphorylation tau signaling. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exploration, anxiety, and spatial memory in transgenic anophthalmic mice.

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Buhot, M C; Dubayle, D; Malleret, G; Javerzat, S; Segu, L

2001-04-01

Contradictory results are found in the literature concerning the role of vision in the perception of space or in spatial navigation, in part because of the lack of murine models of total blindness used so far. The authors evaluated the spatial abilities of anophthalmic transgenic mice. These mice did not differ qualitatively from their wild-type littermates in general locomotor activity, spontaneous alternation, object exploration, or anxiety, but their level of exploratory activity was generally lower. In the spatial version of the water maze, they displayed persistent thigmotaxic behavior and showed severe spatial learning impairments. However, their performances improved with training, suggesting that they may have acquired a rough representation of the platform position. These results suggest that modalities other than vision enable some degree of spatial processing in proximal and structured spaces but that vision is critical for accurate spatial navigation.

Eicosanoyl-5-hydroxytryptamide (EHT prevents Alzheimer's disease-related cognitive and electrophysiological impairments in mice exposed to elevated concentrations of oligomeric beta-amyloid.

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Kesava Asam

Full Text Available Soluble forms of oligomeric beta-amyloid (Aβ are thought to play a central role in Alzheimer's disease (AD. Transgenic manipulation of methylation of the serine/threonine protein phosphatase, PP2A, was recently shown to alter the sensitivity of mice to AD-related impairments resulting from acute exposure to elevated levels of Aβ. In addition, eicosanoyl-5-hydroxytryptamide (EHT, a naturally occurring component from coffee beans that modulates PP2A methylation, was shown to confer therapeutic benefits in rodent models of AD and Parkinson's disease. Here, we tested the hypothesis that EHT protects animals from the pathological effects of exposure to elevated levels of soluble oligomeric Aβ. We treated mice with EHT-containing food at two different doses and assessed the sensitivity of these animals to Aβ-induced behavioral and electrophysiological impairments. We found that EHT administration protected animals from Aβ-induced cognitive impairments in both a radial-arm water maze and contextual fear conditioning task. We also found that both chronic and acute EHT administration prevented Aβ-induced impairments in long-term potentiation. These data add to the accumulating evidence suggesting that interventions with pharmacological agents, such as EHT, that target PP2A activity may be therapeutically beneficial for AD and other neurological conditions.

Neuroprotective and Antiamnesic Effects of Mitragyna inermis Willd (Rubiaceae on Scopolamine-Induced Memory Impairment in Mice

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David Bougolla Pahaye

2017-01-01

Full Text Available Aim. To assess memory improvement and neuroprotective and antioxidant effects of Mitragyna inermis (M. inermis leaf decoction on the central nervous system. Methodology. Leaf decoction of M. inermis was tested on learning and memory in normal and scopolamine-induced cognitive impairment in mice using memory behavioral tests such as the Morris water maze, object recognition task, and elevated plus maze. Oxidative stress enzymes—catalase, superoxide dismutase, and the thiobarbituric acid reactive substance, a product of lipid peroxidation—were quantified. In each test, mice 18 to 25 g were divided into groups of 5. Results. The extract reversed the effects of scopolamine in mice. The extract significantly increased discrimination index in the object recognition task test and inflexion ratio in the elevated plus maze test. The times spent in target quadrant in MWM increased while the transfer latency decreased in mice treated by M. inermis at the dose of 196.5 mg/kg. The activity levels of superoxide dismutase and catalase were significantly increased, whereas the thiobarbituric acid reactive substance was significantly decreased after 8 consecutive days of treatment with M. inermis at the dose of 393 mg/kg. Conclusion. These results suggest that M. inermis leaf extract possess potential antiamnesic effects.

Pharmacologic Treatment Assigned for Niemann Pick Type C1 Disease Partly Changes Behavioral Traits in Wild-Type Mice.

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Schlegel, Victoria; Thieme, Markus; Holzmann, Carsten; Witt, Martin; Grittner, Ulrike; Rolfs, Arndt; Wree, Andreas

2016-11-09

Niemann-Pick Type C1 (NPC1) is an autosomal recessive inherited disorder characterized by accumulation of cholesterol and glycosphingolipids. Previously, we demonstrated that BALB/c-npc1 nih Npc1 -/- mice treated with miglustat, cyclodextrin and allopregnanolone generally performed better than untreated Npc1 -/- animals. Unexpectedly, they also seemed to accomplish motor tests better than their sham-treated wild-type littermates. However, combination-treated mutant mice displayed worse cognition performance compared to sham-treated ones. To evaluate effects of these drugs in healthy BALB/c mice, we here analyzed pharmacologic effects on motor and cognitive behavior of wild-type mice. For combination treatment mice were injected with allopregnanolone/cyclodextrin weekly, starting at P7. Miglustat injections were performed daily from P10 till P23. Starting at P23, miglustat was embedded in the chow. Other mice were treated with miglustat only, or sham-treated. The battery of behavioral tests consisted of accelerod, Morris water maze, elevated plus maze, open field and hot-plate tests. Motor capabilities and spontaneous motor behavior were unaltered in both drug-treated groups. Miglustat-treated wild-type mice displayed impaired spatial learning compared to sham- and combination-treated mice. Both combination- and miglustat-treated mice showed enhanced anxiety in the elevated plus maze compared to sham-treated mice. Additionally, combination treatment as well as miglustat alone significantly reduced brain weight, whereas only combination treatment reduced body weight significantly. Our results suggest that allopregnanolone/cyclodextrin ameliorate most side effects of miglustat in wild-type mice.

Pharmacologic Treatment Assigned for Niemann Pick Type C1 Disease Partly Changes Behavioral Traits in Wild-Type Mice

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Victoria Schlegel

2016-11-01

Full Text Available Niemann-Pick Type C1 (NPC1 is an autosomal recessive inherited disorder characterized by accumulation of cholesterol and glycosphingolipids. Previously, we demonstrated that BALB/c-npc1nihNpc1−/− mice treated with miglustat, cyclodextrin and allopregnanolone generally performed better than untreated Npc1−/− animals. Unexpectedly, they also seemed to accomplish motor tests better than their sham-treated wild-type littermates. However, combination-treated mutant mice displayed worse cognition performance compared to sham-treated ones. To evaluate effects of these drugs in healthy BALB/c mice, we here analyzed pharmacologic effects on motor and cognitive behavior of wild-type mice. For combination treatment mice were injected with allopregnanolone/cyclodextrin weekly, starting at P7. Miglustat injections were performed daily from P10 till P23. Starting at P23, miglustat was embedded in the chow. Other mice were treated with miglustat only, or sham-treated. The battery of behavioral tests consisted of accelerod, Morris water maze, elevated plus maze, open field and hot-plate tests. Motor capabilities and spontaneous motor behavior were unaltered in both drug-treated groups. Miglustat-treated wild-type mice displayed impaired spatial learning compared to sham- and combination-treated mice. Both combination- and miglustat-treated mice showed enhanced anxiety in the elevated plus maze compared to sham-treated mice. Additionally, combination treatment as well as miglustat alone significantly reduced brain weight, whereas only combination treatment reduced body weight significantly. Our results suggest that allopregnanolone/cyclodextrin ameliorate most side effects of miglustat in wild-type mice.

Antioxidant hydrolysed peptides from Manchurian walnut (Juglansmandshurica Maxim.) attenuate scopolamine-induced memory impairment in mice.

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Ren, Dayong; Zhao, Fanrui; Liu, Chunlei; Wang, Ji; Guo, Yong; Liu, Jingsheng; Min, Weihong

2018-04-13

Walnut protein, which is obtained as a by-product of oil expression, has not been used efficiently. Although walnuts are beneficial for cognitive functioning, the potential of their protein composition in strengthening learning and memory functions remains unknown. In this research, the inhibition of memory impairment by the Manchurian walnut hydrolyzed peptide (MWHP) was evaluated. Small-molecular-weight MWHP (<3 kDa) achieved the optimal antioxidative activity. Therefore, MWHP (<3 kDa) was subjected to the following mice trials to evaluate its attenuation effect on memory impairment. In the Morris water maze test, MWHP shortened the total path for searching the platform, reduced the escape latency, and increased the dwelling distance and time in the coverage zone. MWHP also prolonged the latency and diminished errors in the passive avoidance response tests. These behavioral tests demonstrated that MWHP could inhibit scopolamine-induced memory impairment. MWHP improved memory by reducing oxidative stress, inhibiting apoptosis, regulating neurotransmitter functions, maintaining hippocampal CA3 pyramidal neurons, and increasing p-CaMK II levels in brain tissues. Experimental results proved that MWHP exhibits potential in improving memory and should be used to develop novel functional food. This article is protected by copyright. All rights reserved.

Mice lacking the transcriptional regulator Bhlhe40 have enhanced neuronal excitability and impaired synaptic plasticity in the hippocampus.

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Kelly A Hamilton

Full Text Available Bhlhe40 is a transcription factor that is highly expressed in the hippocampus; however, its role in neuronal function is not well understood. Here, we used Bhlhe40 null mice on a congenic C57Bl6/J background (Bhlhe40 KO to investigate the impact of Bhlhe40 on neuronal excitability and synaptic plasticity in the hippocampus. Bhlhe40 KO CA1 neurons had increased miniature excitatory post-synaptic current amplitude and decreased inhibitory post-synaptic current amplitude, indicating CA1 neuronal hyperexcitability. Increased CA1 neuronal excitability was not associated with increased seizure severity as Bhlhe40 KO relative to +/+ (WT control mice injected with the convulsant kainic acid. However, significant reductions in long term potentiation and long term depression at CA1 synapses were observed in Bhlhe40 KO mice, indicating impaired hippocampal synaptic plasticity. Behavioral testing for spatial learning and memory on the Morris Water Maze (MWM revealed that while Bhlhe40 KO mice performed similarly to WT controls initially, when the hidden platform was moved to the opposite quadrant Bhlhe40 KO mice showed impairments in relearning, consistent with decreased hippocampal synaptic plasticity. To investigate possible mechanisms for increased neuronal excitability and decreased synaptic plasticity, a whole genome mRNA expression profile of Bhlhe40 KO hippocampus was performed followed by a chromatin immunoprecipitation sequencing (ChIP-Seq screen of the validated candidate genes for Bhlhe40 protein-DNA interactions consistent with transcriptional regulation. Of the validated genes identified from mRNA expression analysis, insulin degrading enzyme (Ide had the most significantly altered expression in hippocampus and was significantly downregulated on the RNA and protein levels; although Bhlhe40 did not occupy the Ide gene by ChIP-Seq. Together, these findings support a role for Bhlhe40 in regulating neuronal excitability and synaptic plasticity in

Immunization with DAT fragments is associated with long-term striatal impairment, hyperactivity and reduced cognitive flexibility in mice

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Adriani Walter

2012-11-01

Full Text Available Abstract Background Possible interactions between nervous and immune systems in neuro-psychiatric disorders remain elusive. Levels of brain dopamine transporter (DAT have been implicated in several impulse-control disorders, like attention deficit / hyperactivity disorder (ADHD and obsessive-compulsive disorder (OCD. Here, we assessed the interplay between DAT auto-immunity and behavioural / neurochemical phenotype. Methods Male CD-1 mice were immunized with DAT peptide fragments (DAT-i, or vehicle alone (VEH, to generate elevated circulating levels of DAT auto-antibodies (aAbs. Using an operant delay-of-reward task (20 min daily sessions; timeout 25 sec, mice had a choice between either an immediate small amount of food (SS, or a larger amount of food after a delay (LL, which increased progressively across sessions (from 0 to 150 sec. Results DAT-i mice exhibited spontaneous hyperactivity (2 h-longer wake-up peak; a wake-up attempt during rest. Two sub-populations differing in behavioural flexibility were identified in the VEH control group: they showed either a clear-cut decision to select LL or clear-cut shifting towards SS, as expected. Compared to VEH controls, choice-behaviour profile of DAT-i mice was markedly disturbed, together with long-lasting alterations of the striatal monoamines. Enhanced levels of DA metabolite HVA in DAT-i mice came along with slower acquisition of basal preferences and with impaired shifting; elevation also in DOPAC levels was associated with incapacity to change a rigid selection strategy. This scarce flexibility of performance is indicative of a poor adaptation to task contingencies. Conclusions Hyperactivity and reduced cognitive flexibility are patterns of behaviour consistent with enduring functional impairment of striatal regions. It is yet unclear how anti-DAT antibodies could enter or otherwise affect these brain areas, and which alterations in DAT activity exactly occurred after immunization

Chronic liver injury in mice promotes impairment of skin barrier function via tumor necrosis factor-alpha.

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Yokoyama, Satoshi; Hiramoto, Keiichi; Koyama, Mayu; Ooi, Kazuya

2016-09-01

Alcohol is frequently used to induce chronic liver injury in laboratory animals. Alcohol causes oxidative stress in the liver and increases the expression of inflammatory mediators that cause hepatocellular damage. However, during chronic liver injury, it is unclear if/how these liver-derived factors affect distal tissues, such as the skin. The purpose of this study was to evaluate skin barrier function during chronic liver injury. Hairless mice were administered 5% or 10% ethanol for 8 weeks, and damages to the liver and skin were assessed using histological and protein-analysis methods, as well as by detecting inflammatory mediators in the plasma. After alcohol administration, the plasma concentration of the aspartate and alanine aminotransferases increased, while albumin levels decreased. In mice with alcohol-induced liver injury, transepidermal water loss was significantly increased, and skin hydration decreased concurrent with ceramide and type I collagen degradation. The plasma concentrations of [Formula: see text]/[Formula: see text] and tumor necrosis factor-alpha (TNF-α) were significantly increased in mice with induced liver injury. TNF receptor (TNFR) 2 expression was upregulated in the skin of alcohol-administered mice, while TNFR1 levels remained constant. Interestingly, the impairment of skin barrier function in mice administered with 10% ethanol was ameliorated by administering an anti-TNF-α antibody. We propose a novel mechanism whereby plasma TNF-α, via TNFR2 alone or with TNFR1, plays an important role in skin barrier function during chronic liver disease in these mouse models.

Keratinocytes from APP/APLP2-deficient mice are impaired in proliferation, adhesion and migration in vitro

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Siemes, Christina; Quast, Thomas; Kummer, Christiane; Wehner, Sven; Kirfel, Gregor; Mueller, Ulrike; Herzog, Volker

2006-01-01

Growing evidence shows that the soluble N-terminal form (sAPPα) of the amyloid precursor protein (APP) represents an epidermal growth factor fostering keratinocyte proliferation, migration and adhesion. APP is a member of a protein family including the two mammalian amyloid precursor-like proteins APLP1 and APLP2. In the mammalian epidermis, only APP and APLP2 are expressed. APP and APLP2-deficient mice die shortly after birth but do not display a specific epidermal phenotype. In this report, we investigated the epidermis of APP and/or APLP2 knockout mice. Basal keratinocytes showed reduced proliferation in vivo by about 40%. Likewise, isolated keratinocytes exhibited reduced proliferation rates in vitro, which could be completely rescued by either exogenously added recombinant sAPPα, or by co-culture with dermal fibroblasts derived from APP knockout mice. Moreover, APP-knockout keratinocytes revealed reduced migration velocity resulting from severely compromised cell substrate adhesion. Keratinocytes from double knockout mice died within the first week of culture, indicating essential functions of APP-family members for survival in vitro. Our data indicate that sAPPα has to be considered as an essential epidermal growth factor which, however, in vivo can be functionally compensated to a certain extent by other growth factors, e.g., factors released from dermal fibroblasts

Mesenchymal Stem Cells from Patients with Rheumatoid Arthritis Display Impaired Function in Inhibiting Th17 Cells

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Yue Sun

2015-01-01

Full Text Available Mesenchymal stem cells (MSCs possess multipotent and immunomodulatory properties and are suggested to be involved in the pathogenesis of immune-related diseases. This study explored the function of bone marrow MSCs from rheumatoid arthritis (RA patients, focusing on immunomodulatory effects. RA MSCs showed decreased proliferative activity and aberrant migration capacity. No significant differences were observed in cytokine profiles between RA and control MSCs. The effects of RA MSCs on proliferation of peripheral blood mononuclear cells (PBMCs and distribution of specific CD4+ T cell subtypes (Th17, Treg, and Tfh cells were investigated. RA MSCs appeared to be indistinguishable from controls in suppressing PBMC proliferation, decreasing the proportion of Tfh cells, and inducing the polarization of Treg cells. However, the capacity to inhibit Th17 cell polarization was impaired in RA MSCs, which was related to the low expression of CCL2 in RA MSCs after coculture with CD4+ T cells. These findings indicated that RA MSCs display defects in several important biological activities, especially the capacity to inhibit Th17 cell polarization. These functionally impaired MSCs may contribute to the development of RA disease.

Impaired long-term memory retention and working memory in sdy mutant mice with a deletion in Dtnbp1, a susceptibility gene for schizophrenia

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Takao Keizo

2008-10-01

Full Text Available Abstract Background Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. The dystrobrevin-binding protein 1 (DTNBP1: dysbindin-1 gene is a major susceptibility gene for schizophrenia. Genetic variations in DTNBP1 are associated with cognitive functions, general cognitive ability and memory function, and clinical features of patients with schizophrenia including negative symptoms and cognitive decline. Since reduced expression of dysbindin-1 has been observed in postmortem brains of patients with schizophrenia, the sandy (sdy mouse, which has a deletion in the Dtnbp1 gene and expresses no dysbindin-1 protein, could be an animal model of schizophrenia. To address this issue, we have carried out a comprehensive behavioral analysis of the sdy mouse in this study. Results In a rotarod test, sdy mice did not exhibit motor learning whilst the wild type mice did. In a Barnes circular maze test both sdy mice and wild type mice learned to selectively locate the escape hole during the course of the training period and in the probe trial conducted 24 hours after last training. However, sdy mice did not locate the correct hole in the retention probe tests 7 days after the last training trial, whereas wild type mice did, indicating impaired long-term memory retention. A T-maze forced alternation task, a task of working memory, revealed no effect of training in sdy mice despite the obvious effect of training in wild type mice, suggesting a working memory deficit. Conclusion Sdy mouse showed impaired long-term memory retention and working memory. Since genetic variation in DTNBP1 is associated with both schizophrenia and memory function, and memory function is compromised in patients with schizophrenia, the sdy mouse may represent a useful animal model to investigate the mechanisms of memory dysfunction in the disorder.

Impaired Glucose Metabolism in Mice Lacking the Tas1r3 Taste Receptor Gene.

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Murovets, Vladimir O; Bachmanov, Alexander A; Zolotarev, Vasiliy A

2015-01-01

The G-protein-coupled sweet taste receptor dimer T1R2/T1R3 is expressed in taste bud cells in the oral cavity. In recent years, its involvement in membrane glucose sensing was discovered in endocrine cells regulating glucose homeostasis. We investigated importance of extraorally expressed T1R3 taste receptor protein in age-dependent control of blood glucose homeostasis in vivo, using nonfasted mice with a targeted mutation of the Tas1r3 gene that encodes the T1R3 protein. Glucose and insulin tolerance tests, as well as behavioral tests measuring taste responses to sucrose solutions, were performed with C57BL/6ByJ (Tas1r3+/+) inbred mice bearing the wild-type allele and C57BL/6J-Tas1r3tm1Rfm mice lacking the entire Tas1r3 coding region and devoid of the T1R3 protein (Tas1r3-/-). Compared with Tas1r3+/+ mice, Tas1r3-/- mice lacked attraction to sucrose in brief-access licking tests, had diminished taste preferences for sucrose solutions in the two-bottle tests, and had reduced insulin sensitivity and tolerance to glucose administered intraperitoneally or intragastrically, which suggests that these effects are due to absence of T1R3. Impairment of glucose clearance in Tas1r3-/- mice was exacerbated with age after intraperitoneal but not intragastric administration of glucose, pointing to a compensatory role of extraoral T1R3-dependent mechanisms in offsetting age-dependent decline in regulation of glucose homeostasis. Incretin effects were similar in Tas1r3+/+ and Tas1r3-/- mice, which suggests that control of blood glucose clearance is associated with effects of extraoral T1R3 in tissues other than the gastrointestinal tract. Collectively, the obtained data demonstrate that the T1R3 receptor protein plays an important role in control of glucose homeostasis not only by regulating sugar intake but also via its extraoral function, probably in the pancreas and brain.

Impaired Glucose Metabolism in Mice Lacking the Tas1r3 Taste Receptor Gene.

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Vladimir O Murovets

Full Text Available The G-protein-coupled sweet taste receptor dimer T1R2/T1R3 is expressed in taste bud cells in the oral cavity. In recent years, its involvement in membrane glucose sensing was discovered in endocrine cells regulating glucose homeostasis. We investigated importance of extraorally expressed T1R3 taste receptor protein in age-dependent control of blood glucose homeostasis in vivo, using nonfasted mice with a targeted mutation of the Tas1r3 gene that encodes the T1R3 protein. Glucose and insulin tolerance tests, as well as behavioral tests measuring taste responses to sucrose solutions, were performed with C57BL/6ByJ (Tas1r3+/+ inbred mice bearing the wild-type allele and C57BL/6J-Tas1r3tm1Rfm mice lacking the entire Tas1r3 coding region and devoid of the T1R3 protein (Tas1r3-/-. Compared with Tas1r3+/+ mice, Tas1r3-/- mice lacked attraction to sucrose in brief-access licking tests, had diminished taste preferences for sucrose solutions in the two-bottle tests, and had reduced insulin sensitivity and tolerance to glucose administered intraperitoneally or intragastrically, which suggests that these effects are due to absence of T1R3. Impairment of glucose clearance in Tas1r3-/- mice was exacerbated with age after intraperitoneal but not intragastric administration of glucose, pointing to a compensatory role of extraoral T1R3-dependent mechanisms in offsetting age-dependent decline in regulation of glucose homeostasis. Incretin effects were similar in Tas1r3+/+ and Tas1r3-/- mice, which suggests that control of blood glucose clearance is associated with effects of extraoral T1R3 in tissues other than the gastrointestinal tract. Collectively, the obtained data demonstrate that the T1R3 receptor protein plays an important role in control of glucose homeostasis not only by regulating sugar intake but also via its extraoral function, probably in the pancreas and brain.

Abnormal nociception and opiate sensitivity of STOP null mice exhibiting elevated levels of the endogenous alkaloid morphine

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Aunis Dominique

2010-12-01

Full Text Available Abstract Background- Mice deficient for the stable tubule only peptide (STOP display altered dopaminergic neurotransmission associated with severe behavioural defects including disorganized locomotor activity. Endogenous morphine, which is present in nervous tissues and synthesized from dopamine, may contribute to these behavioral alterations since it is thought to play a role in normal and pathological neurotransmission. Results- In this study, we showed that STOP null brain structures, including cortex, hippocampus, cerebellum and spinal cord, contain high endogenous morphine amounts. The presence of elevated levels of morphine was associated with the presence of a higher density of mu opioid receptor with a higher affinity for morphine in STOP null brains. Interestingly, STOP null mice exhibited significantly lower nociceptive thresholds to thermal and mechanical stimulations. They also had abnormal behavioural responses to the administration of exogenous morphine and naloxone. Low dose of morphine (1 mg/kg, i.p. produced a significant mechanical antinociception in STOP null mice whereas it has no effect on wild-type mice. High concentration of naloxone (1 mg/kg was pronociceptive for both mice strain, a lower concentration (0.1 mg/kg was found to increase the mean mechanical nociceptive threshold only in the case of STOP null mice. Conclusions- Together, our data show that STOP null mice displayed elevated levels of endogenous morphine, as well as an increase of morphine receptor affinity and density in brain. This was correlated with hypernociception and impaired pharmacological sensitivity to mu opioid receptor ligands.

Bone-derived mesenchymal stromal cells from HIV transgenic mice exhibit altered proliferation, differentiation capacity and paracrine functions along with impaired therapeutic potential in kidney injury

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Cheng, Kang; Rai, Partab; Lan, Xiqian; Plagov, Andrei; Malhotra, Ashwani; Gupta, Sanjeev; Singhal, Pravin C.

2013-01-01

Mesenchymal stem cells (MSCs) secrete paracrine factors that could be cytoprotective and serve roles in immunoregulation during tissue injury. Although MSCs express HIV receptors, and co-receptors, and are susceptible to HIV infection, whether HIV-1 may affect biological properties of MSCs needs more study. We evaluated cellular proliferation, differentiation and paracrine functions of MSCs isolated from compact bones of healthy control mice and Tg26 HIV-1 transgenic mice. The ability of MSCs to protect against cisplatin toxicity was studied in cultured renal tubular cells as well as in intact mice. We successfully isolated MSCs from healthy mice and Tg26 HIV-1 transgenic mice and found the latter expressed viral Nef, Vpu, NL4-3 and Vif genes. The proliferation and differentiation of Tg26 HIV-1 MSCs was inferior to MSCs from healthy mice. Moreover, transplantation of Tg26 HIV-1 MSCs less effectively improved outcomes compared with healthy MSCs in mice with acute kidney injury. Also, Tg26 HIV-1 MSCs secreted multiple cytokines, but at significantly lower levels than healthy MSCs, which resulted in failure of conditioned medium from these MSCs to protect cultured renal tubular cells from cisplatin toxicity. Therefore, HIV-1 had adverse biological effects on MSCs extending to their proliferation, differentiation, function, and therapeutic potential. These findings will help in advancing mechanistical insight in renal injury and repair in the setting of HIV-1 infection. -- Highlights: •MSCs isolated from HIV mice displayed HIV genes. •MSCs isolated from HIV mice exhibited attenuated growth and paracrine functions. •AKI mice with transplanted HIV-MSC displayed poor outcome. •HIV-1 MSC secreted multiple cytokines but at a lower level

Bone-derived mesenchymal stromal cells from HIV transgenic mice exhibit altered proliferation, differentiation capacity and paracrine functions along with impaired therapeutic potential in kidney injury

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Cheng, Kang; Rai, Partab; Lan, Xiqian; Plagov, Andrei; Malhotra, Ashwani [Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhassett, NY (United States); Gupta, Sanjeev [Departments of Medicine and Pathology, Marion Bessin Liver Research Center, Diabetes Center, Cancer Center, Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Institute for Clinical and Translational Research, Albert Einstein College of Medicine, Bronx, NY (United States); Singhal, Pravin C., E-mail: psinghal@nshs.edu [Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhassett, NY (United States)

2013-08-15

Mesenchymal stem cells (MSCs) secrete paracrine factors that could be cytoprotective and serve roles in immunoregulation during tissue injury. Although MSCs express HIV receptors, and co-receptors, and are susceptible to HIV infection, whether HIV-1 may affect biological properties of MSCs needs more study. We evaluated cellular proliferation, differentiation and paracrine functions of MSCs isolated from compact bones of healthy control mice and Tg26 HIV-1 transgenic mice. The ability of MSCs to protect against cisplatin toxicity was studied in cultured renal tubular cells as well as in intact mice. We successfully isolated MSCs from healthy mice and Tg26 HIV-1 transgenic mice and found the latter expressed viral Nef, Vpu, NL4-3 and Vif genes. The proliferation and differentiation of Tg26 HIV-1 MSCs was inferior to MSCs from healthy mice. Moreover, transplantation of Tg26 HIV-1 MSCs less effectively improved outcomes compared with healthy MSCs in mice with acute kidney injury. Also, Tg26 HIV-1 MSCs secreted multiple cytokines, but at significantly lower levels than healthy MSCs, which resulted in failure of conditioned medium from these MSCs to protect cultured renal tubular cells from cisplatin toxicity. Therefore, HIV-1 had adverse biological effects on MSCs extending to their proliferation, differentiation, function, and therapeutic potential. These findings will help in advancing mechanistical insight in renal injury and repair in the setting of HIV-1 infection. -- Highlights: •MSCs isolated from HIV mice displayed HIV genes. •MSCs isolated from HIV mice exhibited attenuated growth and paracrine functions. •AKI mice with transplanted HIV-MSC displayed poor outcome. •HIV-1 MSC secreted multiple cytokines but at a lower level.

Overexpression of SIRT1 in mouse forebrain impairs lipid/glucose metabolism and motor function.

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Dongmei Wu

Full Text Available SIRT1 plays crucial roles in glucose and lipid metabolism, and has various functions in different tissues including brain. The brain-specific SIRT1 knockout mice display defects in somatotropic signaling, memory and synaptic plasticity. And the female mice without SIRT1 in POMC neuron are more sensitive to diet-induced obesity. Here we created transgenic mice overexpressing SIRT1 in striatum and hippocampus under the control of CaMKIIα promoter. These mice, especially females, exhibited increased fat accumulation accompanied by significant upregulation of adipogenic genes in white adipose tissue. Glucose tolerance of the mice was also impaired with decreased Glut4 mRNA levels in muscle. Moreover, the SIRT1 overexpressing mice showed decreased energy expenditure, and concomitantly mitochondria-related genes were decreased in muscle. In addition, these mice showed unusual spontaneous physical activity pattern, decreased activity in open field and rotarod performance. Further studies demonstrated that SIRT1 deacetylated IRS-2, and upregulated phosphorylation level of IRS-2 and ERK1/2 in striatum. Meanwhile, the neurotransmitter signaling in striatum and the expression of endocrine hormones in hypothalamus and serum T3, T4 levels were altered. Taken together, our findings demonstrate that SIRT1 in forebrain regulates lipid/glucose metabolism and motor function.

Ca2+-clock-dependent pacemaking in the sinus node is impaired in mice with a cardiac specific reduction in SERCA2 abundance

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Sunil Jit Ramamoorthy Jeewanlal Logantha

2016-06-01

Full Text Available Background: The sarcoplasmic reticulum Ca2+-ATPase (SERCA2 pump is an important component of the Ca2+-clock pacemaker mechanism that provides robustness and flexibility to sinus node pacemaking. We have developed transgenic mice with reduced cardiac SERCA2 abundance (Serca2 KO as a model for investigating SERCA2’s role in sinus node pacemaking.Methods and Results: In Serca2 KO mice, ventricular SERCA2a protein content measured by Western blotting was 75% (P70% Serca2 downregulation.Conclusions: Serca2 KO mice show a disrupted Ca2+-clock-dependent pacemaker mechanism contributing to impaired sinus node and atrioventricular node function.

Impaired LRP6-TCF7L2 Activity Enhances Smooth Muscle Cell Plasticity and Causes Coronary Artery Disease

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Roshni Srivastava

2015-10-01

Full Text Available Mutations in Wnt-signaling coreceptor LRP6 have been linked to coronary artery disease (CAD by unknown mechanisms. Here, we show that reduced LRP6 activity in LRP6R611C mice promotes loss of vascular smooth muscle cell (VSMC differentiation, leading to aortic medial hyperplasia. Carotid injury augmented these effects and led to partial to total vascular obstruction. LRP6R611C mice on high-fat diet displayed dramatic obstructive CAD and exhibited an accelerated atherosclerotic burden on LDLR knockout background. Mechanistically, impaired LRP6 activity leads to enhanced non-canonical Wnt signaling, culminating in diminished TCF7L2 and increased Sp1-dependent activation of PDGF signaling. Wnt3a administration to LRP6R611C mice improved LRP6 activity, led to TCF7L2-dependent VSMC differentiation, and rescued post-carotid-injury neointima formation. These findings demonstrate the critical role of intact Wnt signaling in the vessel wall, establish a causal link between impaired LRP6/TCF7L2 activities and arterial disease, and identify Wnt signaling as a therapeutic target against CAD.

Impaired LDL receptor-related protein 1 translocation correlates with improved dyslipidemia and atherosclerosis in apoE-deficient mice.

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Philip L S M Gordts

Full Text Available OBJECTIVE: Determination of the in vivo significance of LDL receptor-related protein 1 (LRP1 dysfunction on lipid metabolism and atherosclerosis development in absence of its main ligand apoE. METHODS AND RESULTS: LRP1 knock-in mice carrying an inactivating mutation in the NPxYxxL motif were crossed with apoE-deficient mice. In the absence of apoE, relative to LRP1 wild-type animals, LRP1 mutated mice showed an increased clearance of postprandial lipids despite a compromised LRP1 endocytosis rate and inefficient insulin-mediated translocation of the receptor to the plasma membrane, likely due to inefficient slow recycling of the mutated receptor. Postprandial lipoprotein improvement was explained by increased hepatic clearance of triglyceride-rich remnant lipoproteins and accompanied by a compensatory 1.6-fold upregulation of LDLR expression in hepatocytes. One year-old apoE-deficient mice having the dysfunctional LRP1 revealed a 3-fold decrease in spontaneous atherosclerosis development and a 2-fold reduction in LDL-cholesterol levels. CONCLUSION: These findings demonstrate that the NPxYxxL motif in LRP1 is important for insulin-mediated translocation and slow perinuclear endosomal recycling. These LRP1 impairments correlated with reduced atherogenesis and cholesterol levels in apoE-deficient mice, likely via compensatory LDLR upregulation.

Regular voluntary exercise cures stress-induced impairment of cognitive function and cell proliferation accompanied by increases in cerebral IGF-1 and GST activity in mice.

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Nakajima, Sanae; Ohsawa, Ikuroh; Ohta, Shigeo; Ohno, Makoto; Mikami, Toshio

2010-08-25

Chronic stress impairs cognitive function and hippocampal neurogenesis. This impairment is attributed to increases in oxidative stress, which result in the accumulation of lipid peroxide. On the other hand, voluntary exercise enhances cognitive function, hippocampal neurogenesis, and antioxidant capacity in normal animals. However, the effects of voluntary exercise on cognitive function, neurogenesis, and antioxidants in stressed mice are unclear. This study was designed to investigate whether voluntary exercise cures stress-induced impairment of cognitive function accompanied by improvement of hippocampal neurogenesis and increases in antioxidant capacity. Stressed mice were exposed to chronic restraint stress (CRS), which consisted of 12h immobilization daily and feeding in a small cage, for 8 weeks. Exercised mice were allowed free access to a running wheel during their exposure to CRS. At the 6th week, cognitive function was examined using the Morris water maze (MWM) test. Daily voluntary exercise restored stress-induced impairment of cognitive function and the hippocampal cell proliferation of newborn cells but not cell survival. Voluntary exercise increased insulin-like growth factor 1 (IGF-1) protein and mRNA expression in the cerebral cortex and liver, respectively. In addition, CRS resulted in a significant increase in the number of 4-hydrosynonenal (4-HNE)-positive cells in the hippocampal dentate gyrus; whereas, voluntary exercise inhibited it and enhanced glutathione s-transferases (GST) activity in the brain. These findings suggest that voluntary exercise attenuated the stress-induced impairment of cognitive function accompanied by improvement of cell proliferation in the dentate gyrus. This exercise-induced improvement was attributed to exercise-induced enhancement of IGF-1 protein and GST activity in the brain. Copyright 2010 Elsevier B.V. All rights reserved.

Hyperglycemia Impairs Neutrophil-Mediated Bacterial Clearance in Mice Infected with the Lyme Disease Pathogen.

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Ashkan Javid

Full Text Available Insulin-insufficient type 1 diabetes is associated with attenuated bactericidal function of neutrophils, which are key mediators of innate immune responses to microbes as well as pathological inflammatory processes. Neutrophils are central to immune responses to the Lyme pathogen Borrelia burgdorferi. The effect of hyperglycemia on host susceptibility to and outcomes of B. burgdorferi infection has not been examined. The present study investigated the impact of sustained obesity-independent hyperglycemia in mice on bacterial clearance, inflammatory pathology and neutrophil responses to B. burgdorferi. Hyperglycemia was associated with reduced arthritis incidence but more widespread tissue colonization and reduced clearance of bacterial DNA in multiple tissues including brain, heart, liver, lung and knee joint. B. burgdorferi uptake and killing were impaired in neutrophils isolated from hyperglycemic mice. Thus, attenuated neutrophil function in insulin-insufficient hyperglycemia was associated with reduced B. burgdorferi clearance in target organs. These data suggest that investigating the effects of comorbid conditions such as diabetes on outcomes of B. burgdorferi infections in humans may be warranted.

Distinct expression of synaptic NR2A and NR2B in the central nervous system and impaired morphine tolerance and physical dependence in mice deficient in postsynaptic density-93 protein

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Johns Roger A

2008-10-01

Full Text Available Abstract Postsynaptic density (PSD-93, a neuronal scaffolding protein, binds to and clusters N-methyl-D-aspartate receptor (NMDAR subunits NR2A and NR2B at cellular membranes in vitro. However, the roles of PSD-93 in synaptic NR2A and NR2B targeting in the central nervous system and NMDAR-dependent physiologic and pathologic processes are still unclear. We report here that PSD-93 deficiency significantly decreased the amount of NR2A and NR2B in the synaptosomal membrane fractions derived from spinal cord dorsal horn and forebrain cortex but did not change their levels in the total soluble fraction from either region. However, PSD-93 deficiency did not markedly change the amounts of NR2A and NR2B in either synaptosomal or total soluble fractions from cerebellum. In mice deficient in PSD-93, morphine dose-dependent curve failed to shift significantly rightward as it did in wild type (WT mice after acute and chronic morphine challenge. Unlike WT mice, PSD-93 knockout mice also showed marked losses of NMDAR-dependent morphine analgesic tolerance and associated abnormal sensitivity in response to mechanical, noxious thermal, and formalin-induced inflammatory stimuli after repeated morphine injection. In addition, PSD-93 knockout mice displayed dramatic loss of jumping activity, a typical NMDAR-mediated morphine withdrawal abstinence behavior. These findings indicate that impaired NMDAR-dependent neuronal plasticity following repeated morphine injection in PSD-93 knockout mice is attributed to PSD-93 deletion-induced alterations of synaptic NR2A and NR2B expression in dorsal horn and forebrain cortex neurons. The selective effect of PSD-93 deletion on synaptic NMDAR expression in these two major pain-related regions might provide the better strategies for the prevention and treatment of opioid tolerance and physical dependence.

Cardiac Ablation of Rheb1 Induces Impaired Heart Growth, Endoplasmic Reticulum-Associated Apoptosis and Heart Failure in Infant Mice

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Cao, Yunshan; Tao, Lichan; Shen, Shutong; Xiao, Junjie; Wu, Hang; Li, Beibei; Wu, Xiangqi; Luo, Wen; Xiao, Qi; Hu, Xiaoshan; Liu, Hailang; Nie, Junwei; Lu, Shuangshuang; Yuan, Baiyin; Han, Zhonglin; Xiao, Bo; Yang, Zhongzhou; Li, Xinli

2013-01-01

Ras homologue enriched in brain 1 (Rheb1) plays an important role in a variety of cellular processes. In this study, we investigate the role of Rheb1 in the post-natal heart. We found that deletion of the gene responsible for production of Rheb1 from cardiomyocytes of post-natal mice resulted in malignant arrhythmias, heart failure, and premature death of these mice. In addition, heart growth impairment, aberrant metabolism relative gene expression, and increased cardiomyocyte apoptosis were observed in Rheb1-knockout mice prior to the development of heart failure and arrhythmias. Also, protein kinase B (PKB/Akt) signaling was enhanced in Rheb1-knockout mice, and removal of phosphatase and tensin homolog (Pten) significantly prolonged the survival of Rheb1-knockouts. Furthermore, signaling via the mammalian target of rapamycin complex 1 (mTORC1) was abolished and C/EBP homologous protein (CHOP) and phosphorylation levels of c-Jun N-terminal kinase (JNK) were increased in Rheb1 mutant mice. In conclusion, this study demonstrates that Rheb1 is important for maintaining cardiac function in post-natal mice via regulation of mTORC1 activity and stress on the endoplasmic reticulum. Moreover, activation of Akt signaling helps to improve the survival of mice with advanced heart failure. Thus, this study provides direct evidence that Rheb1 performs multiple important functions in the heart of the post-natal mouse. Enhancing Akt activity improves the survival of infant mice with advanced heart failure. PMID:24351823

Glutaminase-Deficient Mice Display Hippocampal Hypoactivity, Insensitivity to Pro-Psychotic Drugs and Potentiated Latent Inhibition: Relevance to Schizophrenia

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Gaisler-Salomon, Inna; Miller, Gretchen M; Chuhma, Nao; Lee, Sooyeon; Zhang, Hong; Ghoddoussi, Farhad; Lewandowski, Nicole; Fairhurst, Stephen; Wang, Yvonne; Conjard-Duplany, Agnès; Masson, Justine; Balsam, Peter; Hen, René; Arancio, Ottavio; Galloway, Matthew P; Moore, Holly M; Small, Scott A; Rayport, Stephen

2009-01-01

Dysregulated glutamatergic neurotransmission has been strongly implicated in the pathophysiology of schizophrenia (SCZ). Recently, presynaptic modulation of glutamate transmission has been shown to have therapeutic promise. We asked whether genetic knockdown of glutaminase (gene GLS1) to reduce glutamatergic transmission presynaptically by slowing the recycling of glutamine to glutamate, would produce a phenotype relevant to SCZ and its treatment. GLS1 heterozygous (GLS1 het) mice showed about a 50% global reduction in glutaminase activity, and a modest reduction in glutamate levels in brain regions relevant to SCZ pathophysiology, but displayed neither general behavioral abnormalities nor SCZ-associated phenotypes. Functional imaging, measuring regional cerebral blood volume, showed hippocampal hypometabolism mainly in the CA1 subregion and subiculum, the inverse of recent clinical imaging findings in prodromal and SCZ patients. GLS1 het mice were less sensitive to the behavioral stimulating effects of amphetamine, showed a reduction in amphetamine-induced striatal dopamine release and in ketamine-induced frontal cortical activation, suggesting that GLS1 het mice are resistant to the effects of these pro-psychotic challenges. Moreover, GLS1 het mice showed clozapine-like potentiation of latent inhibition, suggesting that reduction in glutaminase has antipsychotic-like properties. These observations provide further support for the pivotal role of altered glutamatergic synaptic transmission in the pathophysiology of SCZ, and suggest that presynaptic modulation of the glutamine–glutamate pathway through glutaminase inhibition may provide a new direction for the pharmacotherapy of SCZ. PMID:19516252

Effector and naturally occurring regulatory T cells display no abnormalities in activation induced cell death in NOD mice.

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Ayelet Kaminitz

Full Text Available BACKGROUND: Disturbed peripheral negative regulation might contribute to evolution of autoimmune insulitis in type 1 diabetes. This study evaluates the sensitivity of naïve/effector (Teff and regulatory T cells (Treg to activation-induced cell death mediated by Fas cross-linking in NOD and wild-type mice. PRINCIPAL FINDINGS: Both effector (CD25(-, FoxP3(- and suppressor (CD25(+, FoxP3(+ CD4(+ T cells are negatively regulated by Fas cross-linking in mixed splenocyte populations of NOD, wild type mice and FoxP3-GFP trangeneess. Proliferation rates and sensitivity to Fas cross-linking are dissociated in Treg cells: fast cycling induced by IL-2 and CD3/CD28 stimulation improve Treg resistance to Fas-ligand (FasL in both strains. The effector and suppressor CD4(+ subsets display balanced sensitivity to negative regulation under baseline conditions, IL-2 and CD3/CD28 stimulation, indicating that stimulation does not perturb immune homeostasis in NOD mice. Effective autocrine apoptosis of diabetogenic cells was evident from delayed onset and reduced incidence of adoptive disease transfer into NOD.SCID by CD4(+CD25(- T cells decorated with FasL protein. Treg resistant to Fas-mediated apoptosis retain suppressive activity in vitro. The only detectable differential response was reduced Teff proliferation and upregulation of CD25 following CD3-activation in NOD mice. CONCLUSION: These data document negative regulation of effector and suppressor cells by Fas cross-linking and dissociation between sensitivity to apoptosis and proliferation in stimulated Treg. There is no evidence that perturbed AICD in NOD mice initiates or promotes autoimmune insulitis.

Mice with an Oncogenic HRAS Mutation are Resistant to High-Fat Diet-Induced Obesity and Exhibit Impaired Hepatic Energy Homeostasis

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Daiju Oba

2018-01-01

Full Text Available Costello syndrome is a “RASopathy” that is characterized by growth retardation, dysmorphic facial appearance, hypertrophic cardiomyopathy and tumor predisposition. >80% of patients with Costello syndrome harbor a heterozygous germline G12S mutation in HRAS. Altered metabolic regulation has been suspected because patients with Costello syndrome exhibit hypoketotic hypoglycemia and increased resting energy expenditure, and their growth is severely retarded. To examine the mechanisms of energy reprogramming by HRAS activation in vivo, we generated knock-in mice expressing a heterozygous Hras G12S mutation (HrasG12S/+ mice as a mouse model of Costello syndrome. On a high-fat diet, HrasG12S/+ mice developed a lean phenotype with microvesicular hepatic steatosis, resulting in early death compared with wild-type mice. Under starvation conditions, hypoketosis and elevated blood levels of long-chain fatty acylcarnitines were observed, suggesting impaired mitochondrial fatty acid oxidation. Our findings suggest that the oncogenic Hras mutation modulates energy homeostasis in vivo.

Lipopolysaccharide-induced brain activation of the indoleamine 2,3-dioxygenase and depressive-like behavior are impaired in a mouse model of metabolic syndrome.

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Dinel, Anne-Laure; André, Caroline; Aubert, Agnès; Ferreira, Guillaume; Layé, Sophie; Castanon, Nathalie

2014-02-01

Although peripheral low-grade inflammation has been associated with a high incidence of mood symptoms in patients with metabolic syndrome (MetS), much less is known about the potential involvement of brain activation of cytokines in that context. Recently we showed in a mouse model of MetS, namely the db/db mice, an enhanced hippocampal inflammation associated with increased anxiety-like behavior (Dinel et al., 2011). However, depressive-like behavior was not affected in db/db mice. Based on the strong association between depressive-like behavior and cytokine-induced brain activation of indoleamine 2,3-dioxygenase (IDO), the enzyme that metabolizes tryptophan along the kynurenine pathway, these results may suggest an impairment of brain IDO activation in db/db mice. To test this hypothesis, we measured the ability of db/db mice and their healthy db/+ littermates to enhance brain IDO activity and depressive-like behavior after a systemic immune challenge with lipopolysaccharide (LPS). Here we show that LPS (5 μg/mouse) significantly increased depressive-like behavior (increased immobility time in a forced-swim test, FST) 24h after treatment in db/+ mice, but not in db/db mice. Interestingly, db/db mice also displayed after LPS treatment blunted increase of brain kynurenine/tryptophan ratio compared to their db/+ counterparts, despite enhanced induction of hippocampal cytokine expression (interleukin-1β, tumor necrosis factor-α). Moreover, this was associated with an impaired effect of LPS on hippocampal expression of the brain-derived neurotrophic factor (BDNF) that contributes to mood regulation, including under inflammatory conditions. Collectively, these data indicate that the rise in brain tryptophan catabolism and depressive-like behavior induced by innate immune system activation is impaired in db/db mice. These findings could have relevance in improving the management and treatment of inflammation-related complications in MetS. Copyright © 2013 Elsevier

Nicotine Significantly Improves Chronic Stress-Induced Impairments of Cognition and Synaptic Plasticity in Mice.

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Shang, Xueliang; Shang, Yingchun; Fu, Jingxuan; Zhang, Tao

2017-08-01

The aim of this study was to examine if nicotine was able to improve cognition deficits in a mouse model of chronic mild stress. Twenty-four male C57BL/6 mice were divided into three groups: control, stress, and stress with nicotine treatment. The animal model was established by combining chronic unpredictable mild stress (CUMS) and isolated feeding. Mice were exposed to CUMS continued for 28 days, while nicotine (0.2 mg/kg) was also administrated for 28 days. Weight and sucrose consumption were measured during model establishing period. The anxiety and behavioral despair were analyzed using the forced swim test (FST) and open-field test (OFT). Spatial cognition was evaluated using Morris water maze (MWM) test. Following behavioral assessment, both long-term potentiation (LTP) and depotentiation (DEP) were recorded in the hippocampal dentate gyrus (DG) region. Both synaptic and Notch1 proteins were measured by Western. Nicotine increased stressed mouse's sucrose consumption. The MWM test showed that spatial learning and reversal learning in stressed animals were remarkably affected relative to controls, whereas nicotine partially rescued cognitive functions. Additionally, nicotine considerably alleviated the level of anxiety and the degree of behavioral despair in stressed mice. It effectively mitigated the depression-induced impairment of hippocampal synaptic plasticity, in which both the LTP and DEP were significantly inhibited in stressed mice. Moreover, nicotine enhanced the expression of synaptic and Notch1 proteins in stressed animals. The results suggest that nicotine ameliorates the depression-like symptoms and improves the hippocampal synaptic plasticity closely associated with activating transmembrane ion channel receptors and Notch signaling components. Graphical Abstract ᅟ.

Decreased spontaneous activity in AMPK alpha 2 muscle specific kinase dead mice is not caused by changes in brain dopamine metabolism

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Møller, Lisbeth Liliendal Valbjørn; Sylow, Lykke; Gøtzsche, Casper René

2016-01-01

was tested in an open field test. Furthermore, we investigated maximal running capacity and voluntary running over a period of 19 days. AMPK α2 KD mice ran 30% less in daily distance compared to WT. Furthermore, AMPK α2 KD mice showed significantly decreased locomotor activity in the open field test compared...... through alterations of the brain dopamine levels specifically in the striatal region. To test this hypothesis, transgenic mice overexpressing an inactivatable dominant negative α2 AMPK construct (AMPK α2 KD) in muscles and littermate wildtype (WT) mice were tested. AMPK α2 KD mice have impaired running...... capacity and display reduced voluntary wheel running activity. Striatal content of dopamine and its metabolites were measured under basal physiological conditions and after cocaine-induced dopamine efflux from the ventral striatum by in vivo microdialysis. Moreover, cocaine-induced locomotor activity...

Differential MR/GR Activation in Mice Results in Emotional States Beneficial or Impairing for Cognition

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Vera Brinks

2007-01-01

Full Text Available Corticosteroids regulate stress response and influence emotion, learning, and memory via two receptors in the brain, the high‐affinity mineralocorticoid (MR and low‐affinity glucocorticoid receptor (GR. We test the hypothesis that MR- and GR-mediated effects interact in emotion and cognition when a novel situation is encountered that is relevant for a learning process. By adrenalectomy and additional constant corticosterone supplement we obtained four groups of male C57BL/6J mice with differential chronic MR and GR activations. Using a hole board task, we found that mice with continuous predominant MR and moderate GR activations were fast learners that displayed low anxiety and arousal together with high directed explorative behavior. Progressive corticosterone concentrations with predominant action via GR induced strong emotional arousal at the expense of cognitive performance. These findings underline the importance of a balanced MR/GR system for emotional and cognitive functioning that is critical for mental health.

Gastroesophageal reflux activates the NF-κB pathway and impairs esophageal barrier function in mice

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Fang, Yu; Chen, Hao; Hu, Yuhui; Djukic, Zorka; Tevebaugh, Whitney; Shaheen, Nicholas J.; Orlando, Roy C.; Hu, Jianguo

2013-01-01

The barrier function of the esophageal epithelium is a major defense against gastroesophageal reflux disease. Previous studies have shown that reflux damage is reflected in a decrease in transepithelial electrical resistance associated with tight junction alterations in the esophageal epithelium. To develop novel therapies, it is critical to understand the molecular mechanisms whereby contact with a refluxate impairs esophageal barrier function. In this study, surgical models of duodenal and mixed reflux were developed in mice. Mouse esophageal epithelium was analyzed by gene microarray. Gene set enrichment analysis showed upregulation of inflammation-related gene sets and the NF-κB pathway due to reflux. Significance analysis of microarrays revealed upregulation of NF-κB target genes. Overexpression of NF-κB subunits (p50 and p65) and NF-κB target genes (matrix metalloproteinases-3 and -9, IL-1β, IL-6, and IL-8) confirmed activation of the NF-κB pathway in the esophageal epithelium. In addition, real-time PCR, Western blotting, and immunohistochemical staining also showed downregulation and mislocalization of claudins-1 and -4. In a second animal experiment, treatment with an NF-κB inhibitor, BAY 11-7085 (20 mg·kg−1·day−1 ip for 10 days), counteracted the effects of duodenal and mixed reflux on epithelial resistance and NF-κB-regulated cytokines. We conclude that gastroesophageal reflux activates the NF-κB pathway and impairs esophageal barrier function in mice and that targeting the NF-κB pathway may strengthen esophageal barrier function against reflux. PMID:23639809

Spirulina maxima Extract Ameliorates Learning and Memory Impairments via Inhibiting GSK-3β Phosphorylation Induced by Intracerebroventricular Injection of Amyloid-β 1-42 in Mice.

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Koh, Eun-Jeong; Kim, Kui-Jin; Song, Ji-Hyeon; Choi, Jia; Lee, Hyeon Yong; Kang, Do-Hyung; Heo, Ho Jin; Lee, Boo-Yong

2017-11-13

Spirulina maxima , a microalga containing high levels of protein and many polyphenols, including chlorophyll a and C-phycocyanin, has antioxidant and anti-inflammatory therapeutic effects. However, the mechanisms where by Spirulina maxima ameliorates cognitive disorders induced by amyloid-β 1-42 (Aβ 1-42 ) are not fully understood. In this study, we investigated whether a 70% ethanol extract of Spirulina maxima (SM70EE) ameliorated cognitive impairments induced by an intracerebroventricular injection of Aβ 1-42 in mice. SM70EE increased the step-through latency time in the passive avoidance test and decreased the escape latency time in the Morris water maze test in Aβ 1-42 -injected mice. SM70EE reduced hippocampal Aβ 1-42 levels and inhibited amyloid precursor protein processing-associated factors in Aβ 1-42 -injected mice. Additionally, acetylcholinesterase activity was suppressed by SM70EE in Aβ 1-42 -injected mice. Hippocampal glutathione levels were examined to determine the effects of SM70EE on oxidative stress in Aβ 1-42 -injected mice. SM70EE increased the levels of glutathione and its associated factors that were reduced in Aβ 1-42 -injected mice. SM70EE also promoted activation of the brain-derived neurotrophic factor/phosphatidylinositol-3 kinase/serine/threonine protein kinase signaling pathway and inhibited glycogen synthase kinase-3β phosphorylation. These findings suggested that SM70EE ameliorated Aβ 1-42 -induced cognitive impairments by inhibiting the increased phosphorylation of glycogen synthase kinase-3β caused by intracerebroventricular injection of Aβ 1-42 in mice.

Brain-Derived Neurotrophic Factor Val66Met Human Polymorphism Impairs the Beneficial Exercise-Induced Neurobiological Changes in Mice

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Ieraci, Alessandro; Madaio, Alessandro I; Mallei, Alessandra; Lee, Francis S; Popoli, Maurizio

2016-01-01

Several studies have shown that exercise improves cognitive functions and emotional behaviors. Positive effects of exercise have been associated with enhanced brain plasticity, adult hippocampal neurogenesis, and increased levels of brain-derived neurotrophic factor (BDNF). However, a substantial variability of individual response to exercise has been described, which may be accounted for by individual genetic variants. Here, we have assessed whether and how the common human BDNF Val66Met polymorphism influences the neurobiological effects modulated by exercise in BDNF Val66Met knock-in male mice. Wild-type (BDNFVal/Val) and homozygous BDNF Val66Met (BDNFMet/Met) male mice were housed in cages equipped with or without running wheels for 4 weeks. Changes in behavioral phenotype, hippocampal adult neurogenesis, and gene expression were evaluated in exercised and sedentary control mice. We found that exercise reduced the latency to feed in the novelty suppressed feeding and the immobility time in the forced swimming test in BDNFVal/Val but not in BDNFMet/Met mice. Hippocampal neurogenesis was reduced in BDNFMet/Met mice compared with BDNFVal/Val mice. BDNFMet/Met mice had lower basal BDNF protein levels in the hippocampus, which was not recovered following exercise. Moreover, exercise-induced expression of total BDNF, BDNF splice variants 1, 2, 4, 6 and fibronectin type III domain-containing protein 5 (FNDC5) mRNA levels were absent or reduced in the dentate gyrus of BDNFMet/Met mice. Exercise failed to enhance PGC-1α and FNDC5 mRNA levels in the BDNFMet/Met muscle. Overall these results indicate that, in adult male mice, the BDNF Val66Met polymorphism impairs the beneficial behavioral and neuroplasticity effects induced by physical exercise. PMID:27388329

Short-term inhibition of 11β-hydroxysteroid dehydrogenase type 1 reversibly improves spatial memory but persistently impairs contextual fear memory in aged mice.

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Wheelan, Nicola; Webster, Scott P; Kenyon, Christopher J; Caughey, Sarah; Walker, Brian R; Holmes, Megan C; Seckl, Jonathan R; Yau, Joyce L W

2015-04-01

High glucocorticoid levels induced by stress enhance the memory of fearful events and may contribute to the development of anxiety and posttraumatic stress disorder. In contrast, elevated glucocorticoids associated with ageing impair spatial memory. We have previously shown that pharmacological inhibition of the intracellular glucocorticoid-amplifying enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) improves spatial memory in aged mice. However, it is not known whether inhibition of 11β-HSD1 will have any beneficial effects on contextual fear memories in aged mice. Here, we examined the effects of UE2316, a selective 11β-HSD1 inhibitor which accesses the brain, on both spatial and contextual fear memories in aged mice using a vehicle-controlled crossover study design. Short-term UE2316 treatment improved spatial memory in aged mice, an effect which was reversed when UE2316 was substituted with vehicle. In contrast, contextual fear memory induced by foot-shock conditioning was significantly reduced by UE2316 in a non-reversible manner. When the order of treatment was reversed following extinction of the original fear memory, and a second foot-shock conditioning was given in a novel context, UE2316 treated aged mice (previously on vehicle) now showed increased fear memory compared to vehicle-treated aged mice (previously on UE2316). Renewal of the original extinguished fear memory triggered by exposure to a new environmental context may explain these effects. Thus 11β-HSD1 inhibition reverses spatial memory impairments with ageing while reducing the strength and persistence of new contextual fear memories. Potentially this could help prevent anxiety-related disorders in vulnerable elderly individuals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Genetic inactivation of Trpml3 does not lead to hearing and vestibular impairment in mice.

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Simone Jörs

2010-12-01

Full Text Available TRPML3, a member of the transient receptor potential (TRP family, is an inwardly rectifying, non-selective Ca2+-permeable cation channel that is regulated by extracytosolic Na+ and H+ and can be activated by a variety of small molecules. The severe auditory and vestibular phenotype of the TRPML3(A419P varitint-waddler mutation made this protein particularly interesting for inner ear biology. To elucidate the physiological role of murine TRPML3, we conditionally inactivated Trpml3 in mice. Surprisingly, lack of functional TRPML3 did not lead to circling behavior, balance impairment or hearing loss.

Behaviour of postnatally growth-impaired mice during malnutrition and after partial weight recovery

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Huber, Reinhard C.; Kolb, Andreas F.; Lillico, Simon

2013-01-01

Objectives: Early malnutrition is a highly prevalent condition in developing countries. Different rodent models of postnatal early malnutrition have been used to approach the subject experimentally, inducing early malnutrition by maternal malnutrition, temporal maternal separation, manipulation...... of litter size or the surgical nipple ligation to impair lactation. Studies on the behaviour of (previously) malnourished animals using animal models have produced sometimes contradictory results regarding the effects of early postnatal malnutrition and have been criticized for introducing potential...... confounding factors. The present paper is a first report on the behavioural effects of early malnutrition induced by an alternative approach: mice nursed by a-casein-deficient knockout dams showed a severe growth delay during early development and substantial catch-up growth after weaning when compared...

Impaired spatial learning strategies and novel object recognition in mice haploinsufficient for the dual specificity tyrosine-regulated kinase-1A (Dyrk1A.

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Glòria Arqué

Full Text Available BACKGROUND: Pathogenic aneuploidies involve the concept of dosage-sensitive genes leading to over- and underexpression phenotypes. Monosomy 21 in human leads to mental retardation and skeletal, immune and respiratory function disturbances. Most of the human condition corresponds to partial monosomies suggesting that critical haploinsufficient genes may be responsible for the phenotypes. The DYRK1A gene is localized on the human chromosome 21q22.2 region, and has been proposed to participate in monosomy 21 phenotypes. It encodes a dual-specificity kinase involved in neuronal development and in adult brain physiology, but its possible role as critical haploinsufficient gene in cognitive function has not been explored. METHODOLOGY/PRINCIPAL FINDINGS: We used mice heterozygous for a Dyrk1A targeted mutation (Dyrk1A+/- to investigate the implication of this gene in the cognitive phenotypes of monosomy 21. Performance of Dyrk1A+/- mice was assayed 1/ in a navigational task using the standard hippocampally related version of the Morris water maze, 2/ in a swimming test designed to reveal potential kinesthetic and stress-related behavioral differences between control and heterozygous mice under two levels of aversiveness (25 degrees C and 17 degrees C and 3/ in a long-term novel object recognition task, sensitive to hippocampal damage. Dyrk1A+/- mice showed impairment in the development of spatial learning strategies in a hippocampally-dependent memory task, they were impaired in their novel object recognition ability and were more sensitive to aversive conditions in the swimming test than euploid control animals. CONCLUSIONS/SIGNIFICANCE: The present results are clear examples where removal of a single gene has a profound effect on phenotype and indicate that haploinsufficiency of DYRK1A might contribute to an impairment of cognitive functions and stress coping behavior in human monosomy 21.

A Longitudinal Study of Cognition, Proton MR Spectroscopy and Synaptic and Neuronal Pathology in Aging Wild-type and AβPPswe-PS1dE9 Mice

Science.gov (United States)

Jansen, Diane; Zerbi, Valerio; Janssen, Carola I. F.; Dederen, Pieter J. W. C.; Mutsaers, Martina P. C.; Hafkemeijer, Anne; Janssen, Anna-Lena; Nobelen, Cindy L. M.; Veltien, Andor; Asten, Jack J.; Heerschap, Arend; Kiliaan, Amanda J.

2013-01-01

Proton magnetic resonance spectroscopy (1H MRS) is a valuable tool in Alzheimer’s disease research, investigating the functional integrity of the brain. The present longitudinal study set out to characterize the neurochemical profile of the hippocampus, measured by single voxel 1H MRS at 7 Tesla, in the brains of AβPPSswe-PS1dE9 and wild-type mice at 8 and 12 months of age. Furthermore, we wanted to determine whether alterations in hippocampal metabolite levels coincided with behavioral changes, cognitive decline and neuropathological features, to gain a better understanding of the underlying neurodegenerative processes. Moreover, correlation analyses were performed in the 12-month-old AβPP-PS1 animals with the hippocampal amyloid-β deposition, TBS-T soluble Aβ levels and high-molecular weight Aβ aggregate levels to gain a better understanding of the possible involvement of Aβ in neurochemical and behavioral changes, cognitive decline and neuropathological features in AβPP-PS1 transgenic mice. Our results show that at 8 months of age AβPPswe-PS1dE9 mice display behavioral and cognitive changes compared to age-matched wild-type mice, as determined in the open field and the (reverse) Morris water maze. However, there were no variations in hippocampal metabolite levels at this age. AβPP-PS1 mice at 12 months of age display more severe behavioral and cognitive impairment, which coincided with alterations in hippocampal metabolite levels that suggest reduced neuronal integrity. Furthermore, correlation analyses suggest a possible role of Aβ in inflammatory processes, synaptic dysfunction and impaired neurogenesis. PMID:23717459

Chronic administration of R-flurbiprofen attenuates learning impairments in transgenic amyloid precursor protein mice

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Kukar, Thomas; Prescott, Sonya; Eriksen, Jason L; Holloway, Vallie; Murphy, M Paul; Koo, Edward H; Golde, Todd E; Nicolle, Michelle M

2007-01-01

ability to selectively target Aβ42 production and improve cognitive impairments in transgenic APP mice, as well as promising data from a phase 2 human clinical trial, future studies are needed to investigate the utility of R-flurbiprofen as an AD therapeutic and its possible mechanisms of action. PMID:17650315

Chronic administration of R-flurbiprofen attenuates learning impairments in transgenic amyloid precursor protein mice

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Koo Edward H

2007-07-01

in Tg2576 mice. Given its ability to selectively target Aβ42 production and improve cognitive impairments in transgenic APP mice, as well as promising data from a phase 2 human clinical trial, future studies are needed to investigate the utility of R-flurbiprofen as an AD therapeutic and its possible mechanisms of action.

Effect of the Oculus Rift head mounted display on postural stability

DEFF Research Database (Denmark)

Epure, Paula; Gheorghe, Cristina; Nissen, Thomas

2014-01-01

board controlling a skiing game. Two tests were conducted: full-vision versus blindfolded and HMD versus monitor display. Results were that five of the six balance-impaired adults and six of the eight non-balance-impaired adults showed higher degree of postural stability while using a monitor display......This study explored how a HMD-experienced virtual environment influences physical balance of six balance-impaired adults 59-69 years-of-age, when compared to a control group of eight non-balance-impaired adults, 18-28 years-of-age. The setup included a Microsoft Kinect and a self-created balance....... Conclusions are that HMD, used in this context, leads to postural instability....

Primary coenzyme Q deficiency in Pdss2 mutant mice causes isolated renal disease.

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Min Peng

2008-04-01

Full Text Available 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 Pdss2(kd/kd genotype can be attributed to a mitochondrial CoQ biosynthetic defect. Levels of CoQ9 and CoQ10 in kidney homogenates from B6.Pdss2(kd/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,Pdss2(loxP/loxP knockout mice but not in conditional knockouts targeted to renal tubular epithelium, monocytes, or hepatocytes. Liver-conditional B6.Alb/cre,Pdss2(loxP/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.

Cyclic GMP-AMP Displays Mucosal Adjuvant Activity in Mice

OpenAIRE

Škrnjug, Ivana; Guzmán, Carlos Alberto; Ruecker, Christine

2014-01-01

The recently discovered mammalian enzyme cyclic GMP-AMP synthase produces cyclic GMP-AMP (cGAMP) after being activated by pathogen-derived cytosolic double stranded DNA. The product can stimulate STING-dependent interferon type I signaling. Here, we explore the efficacy of cGAMP as a mucosal adjuvant in mice. We show that cGAMP can enhance the adaptive immune response to the model antigen ovalbumin. It promotes antigen specific IgG and a balanced Th1/Th2 lymphocyte response in immunized mice....

Cannabinoid 1 receptor knockout mice display cold allodynia, but enhanced recovery from spared-nerve injury-induced mechanical hypersensitivity.

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Sideris, Alexandra; Piskoun, Boris; Russo, Lori; Norcini, Monica; Blanck, Thomas; Recio-Pinto, Esperanza

2016-01-01

significant recovery from spared-nerve injury-induced mechanical hypersensitivity are two novel phenotypes which characterize the global CB1R-/- mice. An increase in transient receptor potential channel of melastatin 8 channel function in DRG neurons may underlie the cold phenotype. Recovery of mechanical thresholds in the CB1R knockouts was independent of motor function. These results indicate that CB1R expression contributes to the development of persistent mechanical hypersensitivity, protects against the development of robust cold allodynia but is not involved in motor impairment following spared-nerve injury in mice. © The Author(s) 2016.

Exposure to electronic cigarettes impairs pulmonary anti-bacterial and anti-viral defenses in a mouse model.

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Thomas E Sussan

Full Text Available Electronic cigarettes (E-cigs have experienced sharp increases in popularity over the past five years due to many factors, including aggressive marketing, increased restrictions on conventional cigarettes, and a perception that E-cigs are healthy alternatives to cigarettes. Despite this perception, studies on health effects in humans are extremely limited and in vivo animal models have not been generated. Presently, we determined that E-cig vapor contains 7 x 10(11 free radicals per puff. To determine whether E-cig exposure impacts pulmonary responses in mice, we developed an inhalation chamber for E-cig exposure. Mice that were exposed to E-cig vapor contained serum cotinine concentrations that are comparable to human E-cig users. E-cig exposure for 2 weeks produced a significant increase in oxidative stress and moderate macrophage-mediated inflammation. Since, COPD patients are susceptible to bacterial and viral infections, we tested effects of E-cigs on immune response. Mice that were exposed to E-cig vapor showed significantly impaired pulmonary bacterial clearance, compared to air-exposed mice, following an intranasal infection with Streptococcus pneumonia. This defective bacterial clearance was partially due to reduced phagocytosis by alveolar macrophages from E-cig exposed mice. In response to Influenza A virus infection, E-cig exposed mice displayed increased lung viral titers and enhanced virus-induced illness and mortality. In summary, this study reports a murine model of E-cig exposure and demonstrates that E-cig exposure elicits impaired pulmonary anti-microbial defenses. Hence, E-cig exposure as an alternative to cigarette smoking must be rigorously tested in users for their effects on immune response and susceptibility to bacterial and viral infections.

Proinflammatory Stimulation of Toll-Like Receptor 9 with High Dose CpG ODN 1826 Impairs Endothelial Regeneration and Promotes Atherosclerosis in Mice.

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Alexander O Krogmann

Full Text Available Toll-like receptors (TLR of the innate immune system have been closely linked with the development of atherosclerotic lesions. TLR9 is activated by unmethylated CpG motifs within ssDNA, but also by CpG motifs in nucleic acids released during vascular apoptosis and necrosis. The role of TLR9 in vascular disease remains controversial and we sought to investigate the effects of a proinflammatory TLR9 stimulation in mice.TLR9-stimulation with high dose CpG ODN at concentrations between 6.25 nM to 30 nM induced a significant proinflammatory cytokine response in mice. This was associated with impaired reendothelialization upon acute denudation of the carotid and increased numbers of circulating endothelial microparticles, as a marker for amplified endothelial damage. Chronic TLR9 agonism in apolipoprotein E-deficient (ApoE-/- mice fed a cholesterol-rich diet increased aortic production of reactive oxygen species, the number of circulating endothelial microparticles, circulating sca-1/flk-1 positive cells, and most importantly augmented atherosclerotic plaque formation when compared to vehicle treated animals. Importantly, high concentrations of CpG ODN are required for these proatherogenic effects.Systemic stimulation of TLR9 with high dose CpG ODN impaired reendothelialization upon acute vascular injury and increased atherosclerotic plaque development in ApoE-/- mice. Further studies are necessary to fully decipher the contradictory finding of TLR9 agonism in vascular biology.

Extracellular superoxide dismutase deficiency impairs wound healing in advanced age by reducing neovascularization and fibroblast function.

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Fujiwara, Toshihiro; Duscher, Dominik; Rustad, Kristine C; Kosaraju, Revanth; Rodrigues, Melanie; Whittam, Alexander J; Januszyk, Michael; Maan, Zeshaan N; Gurtner, Geoffrey C

2016-03-01

Advanced age is characterized by impairments in wound healing, and evidence is accumulating that this may be due in part to a concomitant increase in oxidative stress. Extended exposure to reactive oxygen species (ROS) is thought to lead to cellular dysfunction and organismal death via the destructive oxidation of intra-cellular proteins, lipids and nucleic acids. Extracellular superoxide dismutase (ecSOD/SOD3) is a prime antioxidant enzyme in the extracellular space that eliminates ROS. Here, we demonstrate that reduced SOD3 levels contribute to healing impairments in aged mice. These impairments include delayed wound closure, reduced neovascularization, impaired fibroblast proliferation and increased neutrophil recruitment. We further establish that SOD3 KO and aged fibroblasts both display reduced production of TGF-β1, leading to decreased differentiation of fibroblasts into myofibroblasts. Taken together, these results suggest that wound healing impairments in ageing are associated with increased levels of ROS, decreased SOD3 expression and impaired extracellular oxidative stress regulation. Our results identify SOD3 as a possible target to correct age-related cellular dysfunction in wound healing. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Obese Mice Fed a Diet Supplemented with Enzyme-Treated Wheat Bran Display Marked Shifts in the Liver Metabolome Concurrent with Altered Gut Bacteria

DEFF Research Database (Denmark)

Kieffer, Dorothy A.; Piccolo, Brian D.; Marco, Maria L.

2016-01-01

) associated with specific microbes may be involved. Objective: The objective of this study was to characterize ETWB-driven shifts in the cecal microbiome and to identify correlates between microbial changes and diet-related differences in liver metabolism in diet-induced obese mice that typically display......Background: Enzyme-treated wheat bran (ETWB) contains a fermentable dietary fiber previously shown to decrease liver triglycerides (TGs) and modify the gut microbiome in mice. It is not clear which mechanisms explain how ETWB feeding affects hepatic metabolism, but factors (i.e., xenometabolites...... steatosis. Methods: Five-week-old male C57BL/6J mice fed a 45%-lard based fat diet supplemented with ETWB (20% wt:wt) or rapidly digestible starch (control) (n = 15/group) for 10 wk were characterized by using a multi-omics approach. Multivariate statistical analysis was used to identify variables that were...

Growth Hormone Receptor Antagonist Transgenic Mice Have Increased Subcutaneous Adipose Tissue Mass, Altered Glucose Homeostasis and No Change in White Adipose Tissue Cellular Senescence.

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Comisford, Ross; Lubbers, Ellen R; Householder, Lara A; Suer, Ozan; Tchkonia, Tamara; Kirkland, James L; List, Edward O; Kopchick, John J; Berryman, Darlene E

2016-01-01

Growth hormone (GH)-resistant/deficient mice experience improved glucose homeostasis and substantially increased lifespan. Recent evidence suggests that long-lived GH-resistant/deficient mice are protected from white adipose tissue (WAT) dysfunction, including WAT cellular senescence, impaired adipogenesis and loss of subcutaneous WAT in old age. This preservation of WAT function has been suggested to be a potential mechanism for the extended lifespan of these mice. The objective of this study was to examine WAT senescence, WAT distribution and glucose homeostasis in dwarf GH receptor antagonist (GHA) transgenic mice, a unique mouse strain having decreased GH action but normal longevity. 18-month-old female GHA mice and wild-type (WT) littermate controls were used. Prior to dissection, body composition, fasting blood glucose as well as glucose and insulin tolerance tests were performed. WAT distribution was determined by weighing four distinct WAT depots at the time of dissection. Cellular senescence in four WAT depots was assessed using senescence-associated β-galactosidase staining to quantify the senescent cell burden, and real-time qPCR to quantify gene expression of senescence markers p16 and IL-6. GHA mice had a 22% reduction in total body weight, a 33% reduction in lean mass and a 10% increase in body fat percentage compared to WT controls. GHA mice had normal fasting blood glucose and improved insulin sensitivity; however, they exhibited impaired glucose tolerance. Moreover, GHA mice displayed enhanced lipid storage in the inguinal subcutaneous WAT depot (p < 0.05) and a 1.7-fold increase in extra-/intraperitoneal WAT ratio compared to controls (p < 0.05). Measurements of WAT cellular senescence showed no difference between GHA mice and WT controls. Similar to other mice with decreased GH action, female GHA mice display reduced age-related lipid redistribution and improved insulin sensitivity, but no change in cellular senescence. The similar abundance of

Combination of exercise training and diet restriction normalizes limited exercise capacity and impaired skeletal muscle function in diet-induced diabetic mice.

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Suga, Tadashi; Kinugawa, Shintaro; Takada, Shingo; Kadoguchi, Tomoyasu; Fukushima, Arata; Homma, Tsuneaki; Masaki, Yoshihiro; Furihata, Takaaki; Takahashi, Masashige; Sobirin, Mochamad A; Ono, Taisuke; Hirabayashi, Kagami; Yokota, Takashi; Tanaka, Shinya; Okita, Koichi; Tsutsui, Hiroyuki

2014-01-01

Exercise training (EX) and diet restriction (DR) are essential for effective management of obesity and insulin resistance in diabetes mellitus. However, whether these interventions ameliorate the limited exercise capacity and impaired skeletal muscle function in diabetes patients remains unexplored. Therefore, we investigated the effects of EX and/or DR on exercise capacity and skeletal muscle function in diet-induced diabetic mice. Male C57BL/6J mice that were fed a high-fat diet (HFD) for 8 weeks were randomly assigned for an additional 4 weeks to 4 groups: control, EX, DR, and EX+DR. A lean group fed with a normal diet was also studied. Obesity and insulin resistance induced by a HFD were significantly but partially improved by EX or DR and completely reversed by EX+DR. Although exercise capacity decreased significantly with HFD compared with normal diet, it partially improved with EX and DR and completely reversed with EX+DR. In parallel, the impaired mitochondrial function and enhanced oxidative stress in the skeletal muscle caused by the HFD were normalized only by EX+DR. Although obesity and insulin resistance were completely reversed by DR with an insulin-sensitizing drug or a long-term intervention, the exercise capacity and skeletal muscle function could not be normalized. Therefore, improvement in impaired skeletal muscle function, rather than obesity and insulin resistance, may be an important therapeutic target for normalization of the limited exercise capacity in diabetes. In conclusion, a comprehensive lifestyle therapy of exercise and diet normalizes the limited exercise capacity and impaired muscle function in diabetes mellitus.

Refreshable Braille displays using EAP actuators

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Bar-Cohen, Yoseph

2010-04-01

Refreshable Braille can help visually impaired persons benefit from the growing advances in computer technology. The development of such displays in a full screen form is a great challenge due to the need to pack many actuators in small area without interferences. In recent years, various displays using actuators such as piezoelectric stacks have become available in commercial form but most of them are limited to one line Braille code. Researchers in the field of electroactive polymers (EAP) investigated methods of using these materials to form full screen displays. This manuscript reviews the state of the art of producing refreshable Braille displays using EAP-based actuators.

Refreshable Braille Displays Using EAP Actuators

Science.gov (United States)

Bar-Cohen, Yoseph

2010-01-01

Refreshable Braille can help visually impaired persons benefit from the growing advances in computer technology. The development of such displays in a full screen form is a great challenge due to the need to pack many actuators in small area without interferences. In recent years, various displays using actuators such as piezoelectric stacks have become available in commercial form but most of them are limited to one line Braille code. Researchers in the field of electroactive polymers (EAP) investigated methods of using these materials to form full screen displays. This manuscript reviews the state of the art of producing refreshable Braille displays using EAP-based actuators..

Communication impairments in mice lacking Shank1: reduced levels of ultrasonic vocalizations and scent marking behavior.

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Markus Wöhr

Full Text Available Autism is a neurodevelopmental disorder with a strong genetic component. Core symptoms are abnormal reciprocal social interactions, qualitative impairments in communication, and repetitive and stereotyped patterns of behavior with restricted interests. Candidate genes for autism include the SHANK gene family, as mutations in SHANK2 and SHANK3 have been detected in several autistic individuals. SHANK genes code for a family of scaffolding proteins located in the postsynaptic density of excitatory synapses. To test the hypothesis that a mutation in SHANK1 contributes to the symptoms of autism, we evaluated Shank1(-/- null mutant mice for behavioral phenotypes with relevance to autism, focusing on social communication. Ultrasonic vocalizations and the deposition of scent marks appear to be two major modes of mouse communication. Our findings revealed evidence for low levels of ultrasonic vocalizations and scent marks in Shank1(-/- mice as compared to wildtype Shank1(+/+ littermate controls. Shank1(-/- pups emitted fewer vocalizations than Shank1(+/+ pups when isolated from mother and littermates. In adulthood, genotype affected scent marking behavior in the presence of female urinary pheromones. Adult Shank1(-/- males deposited fewer scent marks in proximity to female urine than Shank1(+/+ males. Call emission in response to female urinary pheromones also differed between genotypes. Shank1(+/+ mice changed their calling pattern dependent on previous female interactions, while Shank1(-/- mice were unaffected, indicating a failure of Shank1(-/- males to learn from a social experience. The reduced levels of ultrasonic vocalizations and scent marking behavior in Shank1(-/- mice are consistent with a phenotype relevant to social communication deficits in autism.

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

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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.

Protective effects of Punica granatum seeds extract against aging and scopolamine induced cognitive impairments in mice.

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Kumar, Sokindra; Maheshwari, Kamal Kishore; Singh, Vijender

2008-10-25

Dementia is one of the age related mental problems and characteristic symptom of various neurodegenerative diseases including Alzheimer's disease. This impairment probably is due to the vulnerability of the brain cells to increased oxidative stress during aging process. Many studies have shown that certain phenolic antioxidants attenuate neuronal cell death induced by oxidative stress. The present work was undertaken to assess the effect of ethanolic extract of Punica granatum seeds on cognitive performance of aged and scopolamine treated young mice using one trial step-down type passive avoidance and elevated plus maze task. Aged or scopolamine treated mice showed poor retention of memory in step-down type passive avoidance and in elevated plus maze task. Chronic administration (21 days) of Punica granatum extract and vitamin C significantly (p Punica granatum extract also significantly lowered lipid peroxidation level and increased antioxidant glutathione level in brain tissues. Punica granatum preparations could be protective in the treatment of cognitive disorders such as dementia and Alzheimer's disease.

Thioacetamide-induced cirrhosis in selenium-adequate mice displays rapid and persistent abnormity of hepatic selenoenzymes which are mute to selenium supplementation

International Nuclear Information System (INIS)

Zhang Jinsong; Wang Huali; Yu Hanqing

2007-01-01

Selenium reduction in cirrhosis is frequently reported. The known beneficial effect of selenium supplementation on cirrhosis is probably obtained from nutritionally selenium-deficient subjects. Whether selenium supplementation truly improves cirrhosis in general needs additional experimental investigation. Thioacetamide was used to induce cirrhosis in selenium-adequate and -deficient mice. Selenoenzyme activity and selenium content were measured and the influence of selenium supplementation was evaluated. In Se-adequate mice, thioacetamide-mediated rapid onset of hepatic oxidative stress resulted in an increase in thioredoxin reductase activity and a decrease in both glutathione peroxidase activity and selenium content. The inverse activity of selenoenzymes (i.e. TrxR activity goes up and GPx activity goes down) was persistent and mute to selenium supplementation during the progress of cirrhosis; accordingly, cirrhosis was not improved by selenium supplementation in any period. On the other hand, selenium supplementation to selenium-deficient mice always more efficiently increased hepatic glutathione peroxidase activity and selenium content compared with those treated with thioacetamide, indicating that thioacetamide impairs the liver bioavailability of selenium. Although thioacetamide profoundly affects hepatic selenium status in selenium-adequate mice, selenium supplementation does not modify the changes. Selenium supplementation to cirrhotic subjects with a background of nutritional selenium deficiency can improve selenium status but cannot restore hepatic glutathione peroxidase and selenium to normal levels

Effects of Sleep Deprivation and Aging on Long-Term and Remote Memory in Mice

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Vecsey, Christopher G.; Park, Alan J.; Khatib, Nora; Abel, Ted

2015-01-01

Sleep deprivation (SD) following hippocampus-dependent learning in young mice impairs memory when tested the following day. Here, we examined the effects of SD on remote memory in both young and aged mice. In young mice, we found that memory is still impaired 1 mo after training. SD also impaired memory in aged mice 1 d after training, but, by a…

A Valepotriate Fraction of Valeriana glechomifolia Shows Sedative and Anxiolytic Properties and Impairs Recognition But Not Aversive Memory in Mice

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Natasha Maurmann

2011-01-01

Full Text Available Plants of the genus Valeriana (Valerianaceae are used in traditional medicine as a mild sedative, antispasmodic and tranquilizer in many countries. This study was undertaken to explore the neurobehavioral effects of systemic administration of a valepotriate extract fraction of known quantitative composition of Valeriana glechomifolia (endemic of southern Brazil in mice. Adult animals were treated with a single intraperitoneal injection of valepotriate fraction (VF in the concentrations of 1, 3 or 10 mg kg-1, or with vehicle in the pre-training period before each behavioral test. During the exploration of an open field, mice treated with 10 mg kg-1 of VF showed reduced locomotion and exploratory behavior. Although overall habituation sessions for locomotion and exploratory behavior among vehicle control and doses of VF were not affected, comparison between open-field and habituation sessions within each treatment showed that VF administration at 1 and 10 mg kg-1 impaired habituation. In the elevated plus-maze test, mice treated with VF (10 mg kg-1 showed a significant increase in the percentage of time spent in the open arms without significant effects in the number of total arm entries. VF at 3 mg kg-1 produced an impairment of novel-object recognition memory. In contrast, VF did not affect fear-related memory assessed in an inhibitory avoidance task. The results indicate that VF can have sedative effects and affect behavioral parameters related to recognition memory.

Deleting Both PHLPP1 and CANP1 Rescues Impairments in Long-Term Potentiation and Learning in Both Single Knockout Mice

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Liu, Yan; Sun, Jiandong; Wang, Yubin; Lopez, Dulce; Tran, Jennifer; Bi, Xiaoning; Baudry, Michel

2016-01-01

Calpain-1 (CANP1) has been shown to play a critical role in synaptic plasticity and learning and memory, as its deletion in mice results in impairment in theta-burst stimulation (TBS)-induced LTP and various forms of learning and memory. Likewise, PHLPP1 (aka SCOP) has also been found to participate in learning and memory, as PHLPP1 overexpression…

Arid1b haploinsufficient mice reveal neuropsychiatric phenotypes and reversible causes of growth impairment.

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Celen, Cemre; Chuang, Jen-Chieh; Luo, Xin; Nijem, Nadine; Walker, Angela K; Chen, Fei; Zhang, Shuyuan; Chung, Andrew S; Nguyen, Liem H; Nassour, Ibrahim; Budhipramono, Albert; Sun, Xuxu; Bok, Levinus A; McEntagart, Meriel; Gevers, Evelien F; Birnbaum, Shari G; Eisch, Amelia J; Powell, Craig M; Ge, Woo-Ping; Santen, Gijs We; Chahrour, Maria; Zhu, Hao

2017-07-11

Sequencing studies have implicated haploinsufficiency of ARID1B , a SWI/SNF chromatin-remodeling subunit, in short stature (Yu et al., 2015), autism spectrum disorder (O'Roak et al., 2012), intellectual disability (Deciphering Developmental Disorders Study, 2015), and corpus callosum agenesis (Halgren et al., 2012). In addition, ARID1B is the most common cause of Coffin-Siris syndrome, a developmental delay syndrome characterized by some of the above abnormalities (Santen et al., 2012; Tsurusaki et al., 2012; Wieczorek et al., 2013). We generated Arid1b heterozygous mice, which showed social behavior impairment, altered vocalization, anxiety-like behavior, neuroanatomical abnormalities, and growth impairment. In the brain, Arid1b haploinsufficiency resulted in changes in the expression of SWI/SNF-regulated genes implicated in neuropsychiatric disorders. A focus on reversible mechanisms identified Insulin-like growth factor (IGF1) deficiency with inadequate compensation by Growth hormone-releasing hormone (GHRH) and Growth hormone (GH), underappreciated findings in ARID1B patients. Therapeutically, GH supplementation was able to correct growth retardation and muscle weakness. This model functionally validates the involvement of ARID1B in human disorders, and allows mechanistic dissection of neurodevelopmental diseases linked to chromatin-remodeling.

Short-term inhibition of 11β-hydroxysteroid dehydrogenase type 1 reversibly improves spatial memory but persistently impairs contextual fear memory in aged mice

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Wheelan, Nicola; Webster, Scott P.; Kenyon, Christopher J.; Caughey, Sarah; Walker, Brian R.; Holmes, Megan C.; Seckl, Jonathan R.; Yau, Joyce L.W.

2015-01-01

High glucocorticoid levels induced by stress enhance the memory of fearful events and may contribute to the development of anxiety and posttraumatic stress disorder. In contrast, elevated glucocorticoids associated with ageing impair spatial memory. We have previously shown that pharmacological inhibition of the intracellular glucocorticoid-amplifying enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) improves spatial memory in aged mice. However, it is not known whether inhibition of 11β-HSD1 will have any beneficial effects on contextual fear memories in aged mice. Here, we examined the effects of UE2316, a selective 11β-HSD1 inhibitor which accesses the brain, on both spatial and contextual fear memories in aged mice using a vehicle-controlled crossover study design. Short-term UE2316 treatment improved spatial memory in aged mice, an effect which was reversed when UE2316 was substituted with vehicle. In contrast, contextual fear memory induced by foot-shock conditioning was significantly reduced by UE2316 in a non-reversible manner. When the order of treatment was reversed following extinction of the original fear memory, and a second foot-shock conditioning was given in a novel context, UE2316 treated aged mice (previously on vehicle) now showed increased fear memory compared to vehicle-treated aged mice (previously on UE2316). Renewal of the original extinguished fear memory triggered by exposure to a new environmental context may explain these effects. Thus 11β-HSD1 inhibition reverses spatial memory impairments with ageing while reducing the strength and persistence of new contextual fear memories. Potentially this could help prevent anxiety-related disorders in vulnerable elderly individuals. PMID:25497454

Growth hormone receptor antagonist (GHA) transgenic mice have increased subcutaneous adipose tissue mass, altered glucose homeostasis, and no change in white adipose tissue cellular senescence

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Comisford, Ross; Lubbers, Ellen R.; Householder, Lara; Suer, Ozan; Tchkonia, Tamara; Kirkland, James L.; List, Edward O.; Kopchick, John J.; Berryman, Darlene E.

2015-01-01

Background Growth hormone (GH) resistant/deficient mice experience improved glucose homeostasis and substantially increased lifespan. Recent evidence suggests long-lived GH resistant/deficient mice are protected from white adipose tissue (WAT) dysfunction, including WAT cellular senescence, impaired adipogenesis and loss of subcutaneous WAT in old age. This preservation of WAT function has been suggested to be a potential mechanism for the extended lifespan of these mice. OBJECTIVE The objective of this study was to examine white adipose tissue (WAT) senescence, WAT distribution, and glucose homeostasis in dwarf growth hormone receptor antagonist (GHA) transgenic mice, a unique mouse strain having decreased GH action but normal longevity. METHODS 18mo old female GHA mice and wild type (WT) littermate controls were used. Prior to dissection, body composition, fasting blood glucose, and glucose and insulin tolerance tests were performed. WAT distribution was determined by weighing four distinct WAT depots at the time of dissection. Cellular senescence in four WAT depots was assessed using senescence-associated β-galactosidase (SA-β-gal) staining to quantify the senescent cell burden and real time qPCR to quantify gene expression of senescence markers p16 and IL-6. RESULTS GHA mice had a 22% reduction in total body weight, 33% reduction in lean mass, and a 10% increase in body fat percentage compared to WT controls. GHA mice had normal fasting blood glucose and improved insulin sensitivity; however, they exhibited impaired glucose tolerance. Moreover, GHA mice displayed enhanced lipid storage in the inguinal subcutaneous WAT depot (p<.05) and a 1.7 fold increase in extra-/intraperitoneal WAT ratio compared to controls (p<.05). Measurements of WAT cellular senescence showed no difference between GHA mice and WT controls. CONCLUSIONS Similar to other mice with decreased GH action, female GHA mice display reduced age-related lipid redistribution and improved insulin

Reduction of the cholesterol sensor SCAP in the brains of mice causes impaired synaptic transmission and altered cognitive function.

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Ryo Suzuki

Full Text Available The sterol sensor SCAP is a key regulator of SREBP-2, the major transcription factor controlling cholesterol synthesis. Recently, we showed that there is a global down-regulation of cholesterol synthetic genes, as well as SREBP-2, in the brains of diabetic mice, leading to a reduction of cholesterol synthesis. We now show that in mouse models of type 1 and type 2 diabetes, this is, in part, the result of a decrease of SCAP. Homozygous disruption of the Scap gene in the brains of mice causes perinatal lethality associated with microcephaly and gliosis. Mice with haploinsufficiency of Scap in the brain show a 60% reduction of SCAP protein and ~30% reduction in brain cholesterol synthesis, similar to what is observed in diabetic mice. This results in impaired synaptic transmission, as measured by decreased paired pulse facilitation and long-term potentiation, and is associated with behavioral and cognitive changes. Thus, reduction of SCAP and the consequent suppression of cholesterol synthesis in the brain may play an important role in the increased rates of cognitive decline and Alzheimer disease observed in diabetic states.

Arctigenin effectively ameliorates memory impairment in Alzheimer's disease model mice targeting both β-amyloid production and clearance.

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Zhu, Zhiyuan; Yan, Jianming; Jiang, Wei; Yao, Xin-gang; Chen, Jing; Chen, Lili; Li, Chenjing; Hu, Lihong; Jiang, Hualiang; Shen, Xu

2013-08-07

Alzheimer's disease (AD) chiefly characterizes a progressively neurodegenerative disorder of the brain, and eventually leads to irreversible loss of intellectual abilities. The β-amyloid (Aβ)-induced neurodegeneration is believed to be the main pathological mechanism of AD, and Aβ production inhibition or its clearance promotion is one of the promising therapeutic strategies for anti-AD research. Here, we report that the natural product arctigenin from Arctium lappa (L.) can both inhibit Aβ production by suppressing β-site amyloid precursor protein cleavage enzyme 1 expression and promote Aβ clearance by enhancing autophagy through AKT/mTOR signaling inhibition and AMPK/Raptor pathway activation as investigated in cells and APP/PS1 transgenic AD model mice. Moreover, the results showing that treatment of arctigenin in mice highly decreased Aβ formation and senile plaques and efficiently ameliorated AD mouse memory impairment strongly highlight the potential of arctigenin in anti-AD drug discovery.

Heterozygous Disruption of Autism susceptibility candidate 2 Causes Impaired Emotional Control and Cognitive Memory.

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Kei Hori

Full Text Available Mutations in the Autism susceptibility candidate 2 gene (AUTS2 have been associated with a broad range of psychiatric illnesses including autism spectrum disorders, intellectual disability and schizophrenia. We previously demonstrated that the cytoplasmic AUTS2 acts as an upstream factor for the Rho family small GTPase Rac1 and Cdc42 that regulate the cytoskeletal rearrangements in neural cells. Moreover, genetic ablation of the Auts2 gene in mice has resulted in defects in neuronal migration and neuritogenesis in the developing cerebral cortex caused by inactivation of Rac1-signaling pathway, suggesting that AUTS2 is required for neural development. In this study, we conducted a battery of behavioral analyses on Auts2 heterozygous mutant mice to examine the involvement of Auts2 in adult cognitive brain functions. Auts2-deficient mice displayed a decrease in exploratory behavior as well as lower anxiety-like behaviors in the absence of any motor dysfunction. Furthermore, the capability for novel object recognition and cued associative memory were impaired in Auts2 mutant mice. Social behavior and sensory motor gating functions were, however, normal in the mutant mice as assessed by the three-chamber test and prepulse inhibition test, respectively. Together, our findings indicate that AUTS2 is critical for the acquisition of neurocognitive function.

Chronic consumption of a western diet modifies the DNA methylation profile in the frontal cortex of mice.

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Yokoyama, Amy S; Dunaway, Keith; Rutkowsky, Jennifer; Rutledge, John C; Milenkovic, Dragan

2018-02-21

In our previous work in mice, we have shown that chronic consumption of a Western diet (WD; 42% kcal fat, 0.2% total cholesterol and 34% sucrose) is correlated with impaired cognitive function. Cognitive decline has also been associated with alterations in DNA methylation. Additionally, although there have been many studies analyzing the effect of maternal consumption of a WD on DNA methylation in the offspring, few studies have analyzed how an individual's consumption of a WD can impact his/her DNA methylation. Since the frontal cortex is involved in the regulation of cognitive function and is often affected in cases of cognitive decline, this study aimed to examine how chronic consumption of a WD affects DNA methylation in the frontal cortex of mice. Eight-week-old male mice were fed either a control diet (CD) or a WD for 12 weeks, after which time alterations in DNA methylation were analyzed. Assessment of global DNA methylation in the frontal cortex using dot blot analysis revealed that there was a decrease in global DNA methylation in the WD-fed mice compared with the CD-fed mice. Bioinformatic analysis identified several networks and pathways containing genes displaying differential methylation, particularly those involved in metabolism, cell adhesion and cytoskeleton integrity, inflammation and neurological function. In conclusion, the results from this study suggest that consumption of a WD alters DNA methylation in the frontal cortex of mice and could provide one of the mechanisms by which consumption of a WD impairs cognitive function.

Impaired genome maintenance suppresses the growth hormone--insulin-like growth factor 1 axis in mice with Cockayne syndrome.

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Ingrid van der Pluijm

2007-01-01

Full Text Available Cockayne syndrome (CS is a photosensitive, DNA repair disorder associated with progeria that is caused by a defect in the transcription-coupled repair subpathway of nucleotide excision repair (NER. Here, complete inactivation of NER in Csb(m/m/Xpa(-/- mutants causes a phenotype that reliably mimics the human progeroid CS syndrome. Newborn Csb(m/m/Xpa(-/- mice display attenuated growth, progressive neurological dysfunction, retinal degeneration, cachexia, kyphosis, and die before weaning. Mouse liver transcriptome analysis and several physiological endpoints revealed systemic suppression of the growth hormone/insulin-like growth factor 1 (GH/IGF1 somatotroph axis and oxidative metabolism, increased antioxidant responses, and hypoglycemia together with hepatic glycogen and fat accumulation. Broad genome-wide parallels between Csb(m/m/Xpa(-/- and naturally aged mouse liver transcriptomes suggested that these changes are intrinsic to natural ageing and the DNA repair-deficient mice. Importantly, wild-type mice exposed to a low dose of chronic genotoxic stress recapitulated this response, thereby pointing to a novel link between genome instability and the age-related decline of the somatotroph axis.

Chronic restraint stress promotes learning and memory impairment due to enhanced neuronal endoplasmic reticulum stress in the frontal cortex and hippocampus in male mice.

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Huang, Rong-Rong; Hu, Wen; Yin, Yan-Yan; Wang, Yu-Chan; Li, Wei-Ping; Li, Wei-Zu

2015-02-01

Chronic stress has been implicated in many types of neurodegenerative diseases, such as Alzheimer's disease (AD). In our previous study, we demonstrated that chronic restraint stress (CRS) induced reactive oxygen species (ROS) overproduction and oxidative damage in the frontal cortex and hippocampus in mice. In the present study, we investigated the effects of CRS (over a period of 8 weeks) on learning and memory impairment and endoplasmic reticulum (ER) stress in the frontal cortex and hippocampus in male mice. The Morris water maze was used to investigate the effects of CRS on learning and memory impairment. Immunohistochemistry and immunoblot analysis were also used to determine the expression levels of protein kinase C α (PKCα), 78 kDa glucose-regulated protein (GRP78), C/EBP-homologous protein (CHOP) and mesencephalic astrocyte-derived neurotrophic factor (MANF). The results revealed that CRS significantly accelerated learning and memory impairment, and induced neuronal damage in the frontal cortex and hippocampus CA1 region. Moreover, CRS significantly increased the expression of PKCα, CHOP and MANF, and decreased that of GRP78 in the frontal cortex and hippocampus. Our data suggest that exposure to CRS (for 8 weeks) significantly accelerates learning and memory impairment, and the mechanisms involved may be related to ER stress in the frontal cortex and hippocampus.

A53T-alpha-synuclein overexpression impairs dopamine signaling and striatal synaptic plasticity in old mice.

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Alexander Kurz

2010-07-01

Full Text Available Parkinson's disease (PD, the second most frequent neurodegenerative disorder at old age, can be caused by elevated expression or the A53T missense mutation of the presynaptic protein alpha-synuclein (SNCA. PD is characterized pathologically by the preferential vulnerability of the dopaminergic nigrostriatal projection neurons.Here, we used two mouse lines overexpressing human A53T-SNCA and studied striatal dysfunction in the absence of neurodegeneration to understand early disease mechanisms. To characterize the progression, we employed young adult as well as old mice. Analysis of striatal neurotransmitter content demonstrated that dopamine (DA levels correlated directly with the level of expression of SNCA, an observation also made in SNCA-deficient (knockout, KO mice. However, the elevated DA levels in the striatum of old A53T-SNCA overexpressing mice may not be transmitted appropriately, in view of three observations. First, a transcriptional downregulation of the extraneural DA degradation enzyme catechol-ortho-methytransferase (COMT was found. Second, an upregulation of DA receptors was detected by immunoblots and autoradiography. Third, extensive transcriptome studies via microarrays and quantitative real-time RT-PCR (qPCR of altered transcript levels of the DA-inducible genes Atf2, Cb1, Freq, Homer1 and Pde7b indicated a progressive and genotype-dependent reduction in the postsynaptic DA response. As a functional consequence, long term depression (LTD was absent in corticostriatal slices from old transgenic mice.Taken together, the dysfunctional neurotransmission and impaired synaptic plasticity seen in the A53T-SNCA overexpressing mice reflect early changes within the basal ganglia prior to frank neurodegeneration. As a model of preclinical stages of PD, such insights may help to develop neuroprotective therapeutic approaches.

Communication Impairments in Mice Lacking Shank1: Reduced Levels of Ultrasonic Vocalizations and Scent Marking Behavior

Science.gov (United States)

Wöhr, Markus; Roullet, Florence I.; Hung, Albert Y.; Sheng, Morgan; Crawley, Jacqueline N.

2011-01-01

Autism is a neurodevelopmental disorder with a strong genetic component. Core symptoms are abnormal reciprocal social interactions, qualitative impairments in communication, and repetitive and stereotyped patterns of behavior with restricted interests. Candidate genes for autism include the SHANK gene family, as mutations in SHANK2 and SHANK3 have been detected in several autistic individuals. SHANK genes code for a family of scaffolding proteins located in the postsynaptic density of excitatory synapses. To test the hypothesis that a mutation in SHANK1 contributes to the symptoms of autism, we evaluated Shank1 −/− null mutant mice for behavioral phenotypes with relevance to autism, focusing on social communication. Ultrasonic vocalizations and the deposition of scent marks appear to be two major modes of mouse communication. Our findings revealed evidence for low levels of ultrasonic vocalizations and scent marks in Shank1 −/− mice as compared to wildtype Shank1 +/+ littermate controls. Shank1 −/− pups emitted fewer vocalizations than Shank1+/+ pups when isolated from mother and littermates. In adulthood, genotype affected scent marking behavior in the presence of female urinary pheromones. Adult Shank1 −/− males deposited fewer scent marks in proximity to female urine than Shank1+/+ males. Call emission in response to female urinary pheromones also differed between genotypes. Shank1+/+ mice changed their calling pattern dependent on previous female interactions, while Shank1 −/− mice were unaffected, indicating a failure of Shank1 −/− males to learn from a social experience. The reduced levels of ultrasonic vocalizations and scent marking behavior in Shank1 −/− mice are consistent with a phenotype relevant to social communication deficits in autism. PMID:21695253

Graft-versus-host reaction and immune function. III. Functional pre-T cells in the bone marrow of graft-versus-host-reactive mice displaying T cell immunodeficiency

International Nuclear Information System (INIS)

Seddik, M.; Seemayer, T.A.; Lapp, W.S.

1986-01-01

Studies were performed to determine whether pre-T cells develop normally in the bone marrow of mice displaying thymic dysplasia and T cell immunodeficiency as a consequence of a graft-versus-host (GVH) reaction. GVH reactions were induced in CBAxAF1 mice by the injection of A strain lymphoid cells. To test for the presence of pre-T cells in GVH-reactive mice, bone marrow from GVH-reactive mice (GVHBM) was injected into irradiated syngeneic F1 mice and 30-40 days later thymic morphology and function were studied. Morphology studies showed nearly normal thymic architectural restoration; moreover, such glands contained normal numbers of Thy-1-positive cells. Functional pre-T cells were evaluated by transferring thymocytes from the irradiated GVHBM-reconstituted mice into T-cell-deprived mice. These thymocytes reconstituted allograft reactivity, T helper cell function and Con A and PHA mitogen responses of T-cell-deprived mice. These results suggest that the pre-T cell population in the bone marrow is not affected by the GVH reaction. Therefore, the T cell immunodeficiency associated with the GVH reaction is not due to a deficiency of pre-T cells in the bone marrow but is more likely associated with GVH-induced thymic dysplasia

The secreted L-arabinose isomerase displays anti-hyperglycemic effects in mice.

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Rhimi, Moez; Bermudez-Humaran, Luis G; Huang, Yuan; Boudebbouze, Samira; Gaci, Nadia; Garnier, Alexandrine; Gratadoux, Jean-Jacques; Mkaouar, Héla; Langella, Philippe; Maguin, Emmanuelle

2015-12-21

The L-arabinose isomerase is an intracellular enzyme which converts L-arabinose into L-ribulose in living systems and D-galactose into D-tagatose in industrial processes and at industrial scales. D-tagatose is a natural ketohexose with potential uses in pharmaceutical and food industries. The D-galactose isomerization reaction is thermodynamically equilibrated, and leads to secondary subproducts at high pH. Therefore, an attractive L-arabinose isomerase should be thermoactive and acidotolerant with high catalytic efficiency. While many reports focused on the set out of a low cost process for the industrial production of D-tagatose, these procedures remain costly. When compared to intracellular enzymes, the production of extracellular ones constitutes an interesting strategy to increase the suitability of the biocatalysts. The L-arabinose isomerase (L-AI) from Lactobacillus sakei was expressed in Lactococcus lactis in fusion with the signal peptide of usp45 (SP(Usp45)). The L-AI protein and activity were detected only in the supernatant of the induced cultures of the recombinant L. lactis demonstrating the secretion in the medium of the intracellular L. sakei L-AI in an active form. Moreover, we showed an improvement in the enzyme secretion using either (1) L. lactis strains deficient for their two major proteases, ClpP and HtrA, or (2) an enhancer of protein secretion in L. lactis fused to the recombinant L-AI with the SP(Usp45). Th L-AI enzyme secreted by the recombinant L. lactis strains or produced intracellularly in E. coli, showed the same functional properties than the native enzyme. Furthermore, when mice are fed with the L. lactis strain secreting the L-AI and galactose, tagatose was produced in vivo and reduced the glycemia index. We report for the first time the secretion of the intracellular L-arabinose isomerase in the supernatant of food grade L. lactis cultures with hardly display other secreted proteins. The secreted L-AI originated from the food

Ethanol extract of Scutellaria baicalensis Georgi prevents oxidative damage and neuroinflammation and memorial impairments in artificial senescense mice

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Choi Youkyung

2011-02-01

Full Text Available Abstract Aging is a progressive process related to the accumulation of oxidative damage and neuroinflammation. We tried to find the anti-amnesic effect of the Scutellaria baicalens Georgia (SBG ethanol extract and its major ingredients. The antioxidative effect of SBG on the mice model with memory impairment induced by chronic injection of D-galactose and sodium nitrate was studied. The Y-maze test was used to evaluate the learning and memory function of mice. The activities of superoxide dismutase, catalase and the content of malondialdehyde in brain tissue were used for the antioxidation activities. Neuropathological alteration and expression of bcl-2 protein were investigated in the hippocampus by immunohistochemical staining. ROS, neuroinflammation and apoptosis related molecules expression such as Cox-2, iNOS, procaspase-3, cleaved caspase-3, 8 and 9, bcl-2 and bax protein and the products of iNOS and Cox-2, NO, PGE2, were studied using LPS-activated Raw 264.7 cells and microglia BV2 cells. The cognition of mice was significantly improved by the treatment of baicalein and 50 and 100 mg/kg of SBG in Y-maze test. Both SBG groups showed strong antioxidation, antiinflammation effects with significantly decreased iNOS and Cox-2 expression, NO and PGE2 production, increased bcl-2 and decreased bax and cleaved caspase-3 protein expression in LPS induced Raw 264.7 and BV2 cells. We also found that apoptotic pathway was caused by the intrinsic mitochondrial pathway with the decreased cleaved caspase-9 and unchanged cleaved caspase-8 expression. These findings suggest that SBG, especially high dose, 100 mg/kg, improved the memory impairments significantly and showed antioxidation, antiinflammation and intrinsic caspase-mediated apoptosis effects.

Gestational exposure to titanium dioxide nanoparticles impairs the placentation through dysregulation of vascularization, proliferation and apoptosis in mice.

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Zhang, Lu; Xie, Xingxing; Zhou, Yigang; Yu, Dainan; Deng, Yu; Ouyang, Jiexiu; Yang, Bei; Luo, Dan; Zhang, Dalei; Kuang, Haibin

2018-01-01

Titanium dioxide nanoparticles (TiO 2 NPs) have recently found applications in a wide variety of consumer goods. TiO 2 NPs exposure significantly increases fetal deformities and mortality. However, the potential toxicity of TiO 2 NPs on the growth and development of placenta has been rarely studied during mice pregnancy. The objective of this study was to investigate the effects of maternal exposure of TiO 2 NPs on the placentation. Mice were administered TiO 2 NPs by gavage at 0, 1 and 10 mg/kg/day from gestational day (GD) 1 to GD 13. Uteri and placentas from these mice were collected and counted the numbers of implanted and resorbed embryo and measured the placental weight on GD 13. Placental morphometry was observed by hematoxylin and eosin staining. The levels of Hand1, Esx1 , Eomes , Hand2 , Ascl2 and Fra1 mRNA were assessed by qRT-PCR. Uterine NK (uNK) cells were detected by using DBA lectin. Laminin immunohistochemical staining was to identify fetal vessels. Western blotting and transmission electron micrograph (TEM) were used to assess the apoptosis of placenta. No treatment-related difference was observed in the numbers of implanted and resorbed embryos and weight of placenta between the groups. However, 1 mg/kg/day TiO 2 NPs treatment significantly reduced the ratio of placenta/body weight on GD 13. The proportion of spongiotrophoblast in the 10 mg/kg/day dose group became higher than that in the control group, yet that of labyrinth was significantly lower in 10 mg/kg/day mice. The expression levels of Hand1 , Esx1 , Eomes , Hand2 , Ascl2 and Fra1 mRNA markedly decreased in TiO 2 NP treated placentas. Furthermore, TiO 2 NPs treatment impaired the formation of intricate networks of fetal vessels and reduced the number of uNK cells, and inhibited proliferation and induced apoptosis of placenta by nuclear pyknosis, the activation of caspase-3 and upregulation of Bax protein and downregulation of Bcl-2 protein on GD 13. Gestational exposure to TiO 2 NPs

Neuroligin 2 R215H Mutant Mice Manifest Anxiety, Increased Prepulse Inhibition, and Impaired Spatial Learning and Memory

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Chia-Hsiang Chen

2017-11-01

Full Text Available Neuroligin 2 (NLGN2 is a postsynaptic adhesion protein that plays an essential role in synaptogenesis and function of inhibitory neuron. We previously identified a missense mutation R215H of the NLGN2 in a patient with schizophrenia. This missense mutation was shown to be pathogenic in several cell-based assays. The objective of this study was to better understand the behavioral consequences of this mutation in vivo. We generated a line of transgenic mice carrying this mutation using a recombinant-based method. The mice were subjected to a battery of behavioral tests including open field locomotor activity assay, prepulse inhibition (PPI assay, accelerated rotarod test, novel location and novel recognition tests, elevated plus-maze (EPM test, and Morris water maze test. The transgenic animals were viable and fertile, but the Nlgn2 R215H knock-in (KI homozygous mice showed growth retardation, anxiety-like behavior, increased PPI, and impaired spatial learning and memory. There was no significant interaction between sex and genotype in most behavioral tests; however, we observed a significant interaction between sex and genotype in EPM test in this study. Also, we found that the Nlgn2 R215H homozygous KI mice did not express the NLGN2 protein, resembling Nlgn2 knockout mice. Our results demonstrate that Nlgn2 R215H KI homozygous mice manifest several behavioral abnormalities similar to those found in psychiatric patients carrying NLGN2 mutations, indicating that dysfunction of NLGN2 contributes to the pathogenesis of certain psychiatric symptoms commonly present in various mental disorders, not limited to schizophrenia.

Dorsal hippocampal microinjection of chlorpheniramine reverses the anxiolytic-like effects of l-histidine and impairs emotional memory in mice.

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Canto-de-Souza, L; Garção, D C; Romaguera, F; Mattioli, R

2015-02-05

Several findings have pointed to the role of histaminergic neurotransmission in the modulation of anxiety-like behaviors and emotional memory. The elevated plus-maze (EPM) test has been widely used to investigate the process of anxiety and also has been used to investigate the process of learning and memory. Visual cues are relevant to the formation of spatial maps, and as the hippocampus is involved in this task, experiment 1 explored this issue. Experiment 2 investigated the effects of intraperitoneal (i.p.) injections of l-histidine (LH, a precursor of histamine) and of intra-dorsal hippocampus (intra-DH) injections of chlorpheniramine (CPA, an H1 receptor antagonist) on anxiety and emotional memory in mice re-exposed to the EPM. Mice received saline (SAL) or LH i.p. and SAL or CPA (0.016, 0.052, and 0.16 nmol/0.1 μl) intra-DH prior to Trial 1 (T1) and Trial 2 (T2). No significant changes were observed in the number of enclosed-arm entries (EAE) in T1, an EPM index of general exploratory activity. LH had an anxiolytic-like effect that was reversed by intra-DH injections of CPA. T2 versus T1 analysis revealed that only the lower dose of CPA resulted in impaired emotional memory. Combined injections of LH and CPA revealed that higher doses of CPA impair emotional memory. Taken together, these results suggest that LH and H1 receptors present in the dorsal hippocampus are involved in anxiety-related behaviors and emotional memory in mice submitted to EPM. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Adult vitamin D deficiency exacerbates impairments caused by social stress in BALB/c and C57BL/6 mice.

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Groves, Natalie J; Zhou, Mei; Jhaveri, Dhanisha J; McGrath, John J; Burne, Thomas H J

2017-12-01

Vitamin D deficiency is prevalent in adults throughout the world. Epidemiological studies have shown significant associations between vitamin D deficiency and an increased risk of various neuropsychiatric and neurodegenerative disorders, such as schizophrenia, depression, Alzheimer's disease and cognitive impairment. However, studies based on observational epidemiology cannot address questions of causality; they cannot determine if vitamin D deficiency is a causal factor leading to the adverse health outcome. The main aim of this study was to determine if AVD deficiency would exacerbate the effects of a secondary exposure, in this case social stress, in BALB/c mice and in the more resilient C57BL/6 mice. Ten-week old male BALB/c and C57BL/6 mice were fed a control or vitamin D deficient diet for 10 weeks, and the mice were further separated into one of two groups for social treatment, either Separated (SEP) or Social Defeat (DEF). SEP mice were placed two per cage with a perforated Plexiglas divider, whereas the DEF mice underwent 10days of social defeat prior to behavioural testing. We found that AVD-deficient mice were more vulnerable to the effects of social stress using a social avoidance test, and this was dependent on strain. These results support the hypothesis that vitamin D deficiency may exacerbate behavioural outcomes in mice vulnerable to stress, a finding that can help guide future studies. Importantly, these discoveries support the epidemiological link between vitamin D deficiency and neuropsychiatric and neurodegenerative disorders; and has provided clues that can guide future studies related to unravelling the mechanisms of action linking adult vitamin D deficiency and adverse brain related outcomes. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Impairment of blood lipids pattern in gamma irradiated albino mice and prophylactic role of thiols and W R-2721

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EL-dighidy, E A.M.; El-Kady, M H.R. [National Centre for Radiation Research and Technology, Atomic Energy Authority, Cairo, (Egypt)

1987-12-31

The present work aims to investigate the effect of shot doses of whole body gamma irradiation at the levels, 6, 7.5, 11, 25 and 15 Gy, on the blood lipids pattern in male swiss albino mice. This has been manifested by the levels of total lipids, triglycerides, phospholipids and cholesterol. The radioprotective capacities of two sulfhydryl compounds: thiols and W R-2721, against impairment in blood lipids pattern, have been evaluated in mice received the higher shot radiation dose-level at 15 Gy. Significant increases in the levels of blood total lipid, phospholipids, triglycerides and cholesterol have been recorded on the third day post exposure under the experiment conditions, the data indicated more efficient protection of blood lipid pattern exerted by W R-2721 than in case of thiols. 2 figs., 2 tabs.

Impairment of blood lipids pattern in gamma irradiated albino mice and prophylactic role of thiols and W R-2721

International Nuclear Information System (INIS)

EL-dighidy, E.A.M.; El-Kady, M.H.R.

1986-01-01

The present work aims to investigate the effect of shot doses of whole body gamma irradiation at the levels, 6, 7.5, 11, 25 and 15 Gy, on the blood lipids pattern in male swiss albino mice. This has been manifested by the levels of total lipids, triglycerides, phospholipids and cholesterol. The radioprotective capacities of two sulfhydryl compounds: thiols and W R-2721, against impairment in blood lipids pattern, have been evaluated in mice received the higher shot radiation dose-level at 15 Gy. Significant increases in the levels of blood total lipid, phospholipids, triglycerides and cholesterol have been recorded on the third day post exposure under the experiment conditions, the data indicated more efficient protection of blood lipid pattern exerted by W R-2721 than in case of thiols. 2 figs., 2 tabs

Mitochondria-targeted antioxidant SkQ1 improves impaired dermal wound healing in old mice.

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Demyanenko, Ilya A; Popova, Ekaterina N; Zakharova, Vlada V; Ilyinskaya, Olga P; Vasilieva, Tamara V; Romashchenko, Valeria P; Fedorov, Artem V; Manskikh, Vasily N; Skulachev, Maxim V; Zinovkin, Roman A; Pletjushkina, Olga Yu; Skulachev, Vladimir P; Chernyak, Boris V

2015-07-01

The process of skin wound healing is delayed or impaired in aging animals. To investigate the possible role of mitochondrial reactive oxygen species (mtROS) in cutaneous wound healing of aged mice, we have applied the mitochondria-targeted antioxidant SkQ1. The SkQ1 treatment resulted in accelerated resolution of the inflammatory phase, formation of granulation tissue, vascularization and epithelization of the wounds. The wounds of SkQ1-treated mice contained increased amount of myofibroblasts which produce extracellular matrix proteins and growth factors mediating granulation tissue formation. This effect resembled SkQ1-induced differentiation of fibroblasts to myofibroblast, observed earlierin vitro. The Transforming Growth Factor beta (TGFb) produced by SkQ1-treated fibroblasts was found to stimulated motility of endothelial cells in vitro, an effect which may underlie pro-angiogenic action of SkQ1 in the wounds. In vitro experiments showed that SkQ1 prevented decomposition of VE-cadherin containing contacts and following increase in permeability of endothelial cells monolayer, induced by pro-inflammatory cytokine TNF. Prevention of excessive reaction of endothelium to the pro-inflammatory cytokine(s) might account for anti-inflammatory effect of SkQ1. Our findings point to an important role of mtROS in pathogenesis of age-related chronic wounds.

Oral intake of beet extract provides protection against skin barrier impairment in hairless mice.

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Kawano, Ken-Ichi; Umemura, Kazuo

2013-05-01

The epidermis acts as a functional barrier against the external environment. Disturbances in the function of this barrier cause water loss and increase the chances of penetration by various irritable stimuli, leading to skin diseases such as dry skin, atopic dermatitis, and psoriasis. Ceramides are a critical natural element of the protective epidermal barrier. The aim of this study was to evaluate whether the oral intake of beet (Beta vulgaris) extract, a natural product rich in glucosylceramide (GlcCer), may prevent disturbance in skin barrier function. When HR-1 hairless mice were fed a special diet (HR-AD), transepidermal water loss (TEWL) from the dorsal skin increased, with a compensatory increase in water intake after 5 weeks. Mice fed with HR-AD had dry skin with erythema and showed increased scratching behaviour. Histological examinations revealed a remarkable increase in the thickness of the skin at 8 weeks. Supplemental addition of beet extract, which contained GlcCer at a final concentration of 0.1%, significantly prevented an increase TEWL, water intake, cumulative scratching time, and epidermal thickness at 8 weeks. These results indicate that oral intake of beet extract shows potential for preventing skin diseases associated with impaired skin barrier function. Copyright © 2012 John Wiley & Sons, Ltd.

Obese mice on a high-fat alternate-day fasting regimen lose weight and improve glucose tolerance.

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Joslin, P M N; Bell, R K; Swoap, S J

2017-10-01

Alternate-day fasting (ADF) causes body weight (BW) loss in humans and rodents. However, it is not clear that ADF while maintaining a high-fat (HF) diet results in weight loss and the accompanying improvement in control of circulating glucose. We tested the hypotheses that a high-fat ADF protocol in obese mice would result in (i) BW loss, (ii) improved glucose control, (iii) fluctuating phenotypes on 'fasted' days when compared to 'fed' days and (iv) induction of torpor on 'fasted days'. We evaluated the physiological effects of ADF in diet-induced obese mice for BW, heart rate (HR), body temperature (T b ), glucose tolerance, insulin responsiveness, blood parameters (leptin, insulin, free fatty acids) and hepatic gene expression. Diet-induced obese male C57BL/6J mice lost one-third of their pre-diet BW while on an ADF diet for 10 weeks consisting of HF food. The ADF protocol improved glucose tolerance and insulin sensitivity, although mice on a fast day were less glucose tolerant than the same mice on a fed day. ADF mice on a fast day had low circulating insulin, but had an enhanced response to an insulin-assisted glucose tolerance test, suggesting the impaired glucose tolerance may be a result of insufficient insulin production. On fed days, ADF mice were the warmest, had a high HR and displayed hepatic gene expression and circulating leptin that closely mimicked that of mice fed an ad lib HF diet. ADF mice never entered torpor as assessed by HR and T b . However, on fast days, they were the coolest, had the slowest HR, and displayed hepatic gene expression and circulating leptin that closely mimicked that of Chow-Fed mice. Collectively, the ADF regimen with a HF diet in obese mice results in weight loss, improved blood glucose control, and daily fluctuations in selected physiological and biochemical parameters in the mouse. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Altered behaviour and cognitive function following combined deletion of Toll-like receptors 2 and 4 in mice.

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Too, Lay Khoon; McGregor, Iain S; Baxter, Alan G; Hunt, Nicholas H

2016-04-15

Activation of the immune system due to infection or aging is increasingly linked to impaired neuropsychological function. Toll-like receptors 2 and 4 (TLR2, TLR4) are well-characterised for their role in inflammatory events, and their combined activation has been implicated in neurological diseases. We therefore determined whether TLR2 and TLR4 double gene knockout (GKO) mice showed modified behaviour and cognitive function during a 16-day test sequence that employed the automated IntelliCage test system. The IntelliCage features a home cage environment in which groups of mice live and where water reward is gained through performing various tasks centred on drinking stations in each corner of the apparatus. All mice were tested twice, one month apart (the first sequence termed "R1"and the second "R2"). There were fewer corner visits and nosepokes in TLR2/4 GKO compared to wild-type mice during early exploration in R1, suggesting elevated neophobia in GKO mice. Reduced exploration persisted over subsequent test modules during the dark phase. TLR2/4 GKO mice also displayed increased corner visits during drinking sessions compared to non-drinking sessions, but this was not associated with increased drinking. In subsequent, more complex test modules, TLR2/4 GKO mice had unimpaired spatial learning, but showed markedly poorer performance in a visual discrimination reversal task compared to wild-type mice. These results indicated subtle impairments in behaviour and cognitive functions due to double deficiency in TLR2 and TLR4. These finding are highly relevant to understanding the combined actions of TLR2 and TLR4 on neurological status in a range of different disease conditions. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Co-segregation of hyperactivity, active coping styles and cognitive dysfunction in mice selectively bred for low levels of anxiety

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Yi-Chun eYen

2013-08-01

Full Text Available We established mouse models of extremes in trait anxiety, which are based on selective breeding for low vs. normal vs. high open-arm exploration on the elevated plus-maze. Genetically selected low anxiety-related behavior (LAB coincided with hyperactivity in the home cage. Given the fact that several psychiatric disorders such as schizophrenia, mania and attention deficit hyperactivity disorder (ADHD share hyperactivity symptom, we systematically examined LAB mice with respect to unique and overlapping endophenotypes of the three diseases. To this end Venn diagrams were used as an instrument for discrimination of possible models. We arranged the endophenotypes in Venn diagrams and translated them into different behavioral tests. LAB mice showed elevated levels of locomotion in the open field test with deficits in habituation, compared to mice bred for normal (NAB and high anxiety-related behavior (HAB. Cross-breeding of hypoactive HAB and hyperactive LAB mice resulted in offspring showing a low level of locomotion comparable to HAB mice, indicating that the HAB alleles are dominant over LAB alleles in determining the level of locomotion. In a holeboard test, LAB mice spent less time in hole exploration, as shown in patients with schizophrenia and ADHD; however, LAB mice displayed no impairments in social interaction and prepulse inhibition, implying a unlikelihood of LAB as an animal model of schizophrenia. Although LAB mice displayed hyperarousal, active coping styles and cognitive deficits, symptoms shared by mania and ADHD, they failed to reveal the classic manic endophenotypes, such as increased hedonia and object interaction. The neuroleptic haloperidol reduced locomotor activity in all mouse lines. The mood stabilizer lithium and the psychostimulant amphetamine, in contrast, selectively reduced hyperactivity in LAB mice. Based on the behavioral and pharmacological profiles, LAB mice are suggested as a novel rodent model of ADHD

Co-segregation of hyperactivity, active coping styles, and cognitive dysfunction in mice selectively bred for low levels of anxiety.

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Yen, Yi-Chun; Anderzhanova, Elmira; Bunck, Mirjam; Schuller, Julia; Landgraf, Rainer; Wotjak, Carsten T

2013-01-01

We established mouse models of extremes in trait anxiety, which are based on selective breeding for low vs. normal vs. high open-arm exploration on the elevated plus-maze. Genetically selected low anxiety-related behavior (LAB) coincided with hyperactivity in the home cage. Given the fact that several psychiatric disorders such as schizophrenia, mania, and attention deficit hyperactivity disorder (ADHD) share hyperactivity symptom, we systematically examined LAB mice with respect to unique and overlapping endophenotypes of the three diseases. To this end Venn diagrams were used as an instrument for discrimination of possible models. We arranged the endophenotypes in Venn diagrams and translated them into different behavioral tests. LAB mice showed elevated levels of locomotion in the open field (OF) test with deficits in habituation, compared to mice bred for normal (NAB) and high anxiety-related behavior (HAB). Cross-breeding of hypoactive HAB and hyperactive LAB mice resulted in offspring showing a low level of locomotion comparable to HAB mice, indicating that the HAB alleles are dominant over LAB alleles in determining the level of locomotion. In a holeboard test, LAB mice spent less time in hole exploration, as shown in patients with schizophrenia and ADHD; however, LAB mice displayed no impairments in social interaction and prepulse inhibition (PPI), implying a unlikelihood of LAB as an animal model of schizophrenia. Although LAB mice displayed hyperarousal, active coping styles, and cognitive deficits, symptoms shared by mania and ADHD, they failed to reveal the classic manic endophenotypes, such as increased hedonia and object interaction. The neuroleptic haloperidol reduced locomotor activity in all mouse lines. The mood stabilizer lithium and the psychostimulant amphetamine, in contrast, selectively reduced hyperactivity in LAB mice. Based on the behavioral and pharmacological profiles, LAB mice are suggested as a novel rodent model of ADHD-like symptoms.

Co-segregation of hyperactivity, active coping styles, and cognitive dysfunction in mice selectively bred for low levels of anxiety

Science.gov (United States)

Yen, Yi-Chun; Anderzhanova, Elmira; Bunck, Mirjam; Schuller, Julia; Landgraf, Rainer; Wotjak, Carsten T.

2013-01-01

We established mouse models of extremes in trait anxiety, which are based on selective breeding for low vs. normal vs. high open-arm exploration on the elevated plus-maze. Genetically selected low anxiety-related behavior (LAB) coincided with hyperactivity in the home cage. Given the fact that several psychiatric disorders such as schizophrenia, mania, and attention deficit hyperactivity disorder (ADHD) share hyperactivity symptom, we systematically examined LAB mice with respect to unique and overlapping endophenotypes of the three diseases. To this end Venn diagrams were used as an instrument for discrimination of possible models. We arranged the endophenotypes in Venn diagrams and translated them into different behavioral tests. LAB mice showed elevated levels of locomotion in the open field (OF) test with deficits in habituation, compared to mice bred for normal (NAB) and high anxiety-related behavior (HAB). Cross-breeding of hypoactive HAB and hyperactive LAB mice resulted in offspring showing a low level of locomotion comparable to HAB mice, indicating that the HAB alleles are dominant over LAB alleles in determining the level of locomotion. In a holeboard test, LAB mice spent less time in hole exploration, as shown in patients with schizophrenia and ADHD; however, LAB mice displayed no impairments in social interaction and prepulse inhibition (PPI), implying a unlikelihood of LAB as an animal model of schizophrenia. Although LAB mice displayed hyperarousal, active coping styles, and cognitive deficits, symptoms shared by mania and ADHD, they failed to reveal the classic manic endophenotypes, such as increased hedonia and object interaction. The neuroleptic haloperidol reduced locomotor activity in all mouse lines. The mood stabilizer lithium and the psychostimulant amphetamine, in contrast, selectively reduced hyperactivity in LAB mice. Based on the behavioral and pharmacological profiles, LAB mice are suggested as a novel rodent model of ADHD-like symptoms

The protective effect of 20(S)-protopanaxadiol (PPD) against chronic sleep deprivation (CSD)-induced memory impairments in mice.

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Lu, Cong; Lv, Jingwei; Dong, Liming; Jiang, Ning; Wang, Yan; Fan, Bei; Wang, Fengzhong; Liu, Xinmin

2018-03-01

Sleep deprivation (SD) is associated with oxidative stress that causes learning and memory impairment. 20(S)-Protopanaxadiol (PPD), one of the protopanaxadiol-type saponins, has antioxidant and neuroprotective effect. This study was designed to research the protective effect of PPD against cognitive deficits induced by chronic sleep deprivation (CSD) in mice. The CSD model was induced by subjecting the mice to our self-made Sleep Interruption Apparatus (SIA) continuously for 14 days. The memory enhancing effects of PPD were evaluated by behavioral tests and the related mechanism was further explored by observing the oxidative stress changes in the cortex and hippocampus of mice. The results revealed that PPD (20 and 40 μmol/kg, i.p.) administration significantly improved the cognitive performance of CSD model mice in object location recognition experiment, novel object recognition task and Morris water maze test. Furthermore, PPD effectively restored the levels/activities of antioxidant defense biomarkers in the cortex and hippocampus, including the superoxide dismutase (SOD) enzyme activity, catalase (CAT) enzyme activity, glutathione (GSH), and lipid peroxidation (LPO). In conclusion, PPD could attenuate cognitive deficits induced by CSD, and the neuroprotective effect of PPD might be mediated by alleviation of oxidative stress. It was assumed that PPD has the potential to be a neuroprotective substance for cognition dysfunction. Copyright © 2018 Elsevier Inc. All rights reserved.

Transgenic neuronal expression of proopiomelanocortin attenuates hyperphagic response to fasting and reverses metabolic impairments in leptin-deficient obese mice.

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Mizuno, Tooru M; Kelley, Kevin A; Pasinetti, Giulio M; Roberts, James L; Mobbs, Charles V

2003-11-01

Hypothalamic proopiomelanocortin (POMC) gene expression is reduced in many forms of obesity and diabetes, particularly in those attributable to deficiencies in leptin or its receptor. To assess the functional significance of POMC in mediating metabolic phenotypes associated with leptin deficiency, leptin-deficient mice bearing a transgene expressing the POMC gene under control of the neuron-specific enolase promoter were produced. The POMC transgene attenuated fasting-induced hyperphagia in wild-type mice. Furthermore, the POMC transgene partially reversed obesity, hyperphagia, and hypothermia and effectively normalized hyperglycemia, glucosuria, glucose intolerance, and insulin resistance in leptin-deficient mice. Effects of the POMC transgene on glucose homeostasis were independent of the partial correction of hyperphagia and obesity. Furthermore, the POMC transgene normalized the profile of hepatic and adipose gene expression associated with gluconeogenesis, glucose output, and insulin sensitivity. These results indicate that central POMC is a key modulator of glucose homeostasis and that agonists of POMC products may provide effective therapy in treating impairments in glucose homeostasis when hypothalamic POMC expression is reduced, as occurs with leptin deficiency, hypothalamic damage, and aging.

Peripheral surgical wounding and age-dependent neuroinflammation in mice.

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Zhipeng Xu

Full Text Available Post-operative cognitive dysfunction is associated with morbidity and mortality. However, its neuropathogenesis remains largely to be determined. Neuroinflammation and accumulation of β-amyloid (Aβ have been reported to contribute to cognitive dysfunction in humans and cognitive impairment in animals. Our recent studies have established a pre-clinical model in mice, and have found that the peripheral surgical wounding without the influence of general anesthesia induces an age-dependent Aβ accumulation and cognitive impairment in mice. We therefore set out to assess the effects of peripheral surgical wounding, in the absence of general anesthesia, on neuroinflammation in mice with different ages. Abdominal surgery under local anesthesia was established in 9 and 18 month-old mice. The levels of tumor necrosis factor-α (TNF-α, interleukin-6 (IL-6, Iba1 positive cells (the marker of microglia activation, CD33, and cognitive function in mice were determined. The peripheral surgical wounding increased the levels of TNF-α, IL-6, and Iba1 positive cells in the hippocampus of both 9 and 18 month-old mice, and age potentiated these effects. The peripheral surgical wounding increased the levels of CD33 in the hippocampus of 18, but not 9, month-old mice. Finally, anti-inflammatory drug ibuprofen ameliorated the peripheral surgical wounding-induced cognitive impairment in 18 month-old mice. These data suggested that the peripheral surgical wounding could induce an age-dependent neuroinflammation and elevation of CD33 levels in the hippocampus of mice, which could lead to cognitive impairment in aged mice. Pending further studies, anti-inflammatory therapies may reduce the risk of postoperative cognitive dysfunction in elderly patients.

PX-RICS-deficient mice mimic autism spectrum disorder in Jacobsen syndrome through impaired GABAA receptor trafficking.

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Nakamura, Tsutomu; Arima-Yoshida, Fumiko; Sakaue, Fumika; Nasu-Nishimura, Yukiko; Takeda, Yasuko; Matsuura, Ken; Akshoomoff, Natacha; Mattson, Sarah N; Grossfeld, Paul D; Manabe, Toshiya; Akiyama, Tetsu

2016-03-16

Jacobsen syndrome (JBS) is a rare congenital disorder caused by a terminal deletion of the long arm of chromosome 11. A subset of patients exhibit social behavioural problems that meet the diagnostic criteria for autism spectrum disorder (ASD); however, the underlying molecular pathogenesis remains poorly understood. PX-RICS is located in the chromosomal region commonly deleted in JBS patients with autistic-like behaviour. Here we report that PX-RICS-deficient mice exhibit ASD-like social behaviours and ASD-related comorbidities. PX-RICS-deficient neurons show reduced surface γ-aminobutyric acid type A receptor (GABAAR) levels and impaired GABAAR-mediated synaptic transmission. PX-RICS, GABARAP and 14-3-3ζ/θ form an adaptor complex that interconnects GABAAR and dynein/dynactin, thereby facilitating GABAAR surface expression. ASD-like behavioural abnormalities in PX-RICS-deficient mice are ameliorated by enhancing inhibitory synaptic transmission with a GABAAR agonist. Our findings demonstrate a critical role of PX-RICS in cognition and suggest a causal link between PX-RICS deletion and ASD-like behaviour in JBS patients.

Effects of Social Defeat Stress on Sleep in Mice.

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Henderson, Fiona; Vialou, Vincent; El Mestikawy, Salah; Fabre, Véronique

2017-01-01

Stress plays a key role in the development of psychiatric disorders and has a negative impact on sleep integrity. In mice, chronic social defeat stress (CSDS) is an ethologically valid model of stress-related disorders but little is known about its effects on sleep regulation. Here, we investigated the immediate and long-term effects of 10 consecutive days of social defeat (SD) on vigilance states in C57Bl/6J male mice. Social behavior was assessed to identify susceptible mice, i.e., mice that develop long-lasting social avoidance, and unsusceptible mice. Sleep-wake stages in mice of both groups were analyzed by means of polysomnographic recordings at baseline, after the first, third, and tenth stress sessions and on the 5th recovery day (R5) following the 10-day CSDS. In susceptible mice, each SD session produced biphasic changes in sleep-wake states that were preserved all along 10-day CSDS. These sessions elicited a short-term enhancement of wake time while rapid eye-movement (REM) sleep was strongly inhibited. Concomitantly, delta power was increased during non REM (NREM) sleep. During the following dark period, an increase in total sleep time, as well as wake fragmentation, were observed after each analyzed SD session. Similar changes were observed in unsusceptible mice. At R5, elevated high-frequency EEG activity, as observed in insomniacs, emerged during NREM sleep in both susceptible and unsusceptible groups suggesting that CSDS impaired sleep quality. Furthermore, susceptible but not unsusceptible mice displayed stress-anticipatory arousal during recovery, a common feature of anxiety disorders. Altogether, our findings show that CSDS has profound impacts on vigilance states and further support that sleep is tightly regulated by exposure to stressful events. They also revealed that susceptibility to chronic psychological stress is associated with heightened arousal, a physiological feature of stress vulnerability.

Effects of Social Defeat Stress on Sleep in Mice

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Fiona Henderson

2017-11-01

Full Text Available Stress plays a key role in the development of psychiatric disorders and has a negative impact on sleep integrity. In mice, chronic social defeat stress (CSDS is an ethologically valid model of stress-related disorders but little is known about its effects on sleep regulation. Here, we investigated the immediate and long-term effects of 10 consecutive days of social defeat (SD on vigilance states in C57Bl/6J male mice. Social behavior was assessed to identify susceptible mice, i.e., mice that develop long-lasting social avoidance, and unsusceptible mice. Sleep-wake stages in mice of both groups were analyzed by means of polysomnographic recordings at baseline, after the first, third, and tenth stress sessions and on the 5th recovery day (R5 following the 10-day CSDS. In susceptible mice, each SD session produced biphasic changes in sleep-wake states that were preserved all along 10-day CSDS. These sessions elicited a short-term enhancement of wake time while rapid eye-movement (REM sleep was strongly inhibited. Concomitantly, delta power was increased during non REM (NREM sleep. During the following dark period, an increase in total sleep time, as well as wake fragmentation, were observed after each analyzed SD session. Similar changes were observed in unsusceptible mice. At R5, elevated high-frequency EEG activity, as observed in insomniacs, emerged during NREM sleep in both susceptible and unsusceptible groups suggesting that CSDS impaired sleep quality. Furthermore, susceptible but not unsusceptible mice displayed stress-anticipatory arousal during recovery, a common feature of anxiety disorders. Altogether, our findings show that CSDS has profound impacts on vigilance states and further support that sleep is tightly regulated by exposure to stressful events. They also revealed that susceptibility to chronic psychological stress is associated with heightened arousal, a physiological feature of stress vulnerability.

Neonatal Whisker Trimming Impairs Fear/Anxiety-Related Emotional Systems of the Amygdala and Social Behaviors in Adult Mice.

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Hitomi Soumiya

Full Text Available Abnormalities in tactile perception, such as sensory defensiveness, are common features in autism spectrum disorder (ASD. While not a diagnostic criterion for ASD, deficits in tactile perception contribute to the observed lack of social communication skills. However, the influence of tactile perception deficits on the development of social behaviors remains uncertain, as do the effects on neuronal circuits related to the emotional regulation of social interactions. In neonatal rodents, whiskers are the most important tactile apparatus, so bilateral whisker trimming is used as a model of early tactile deprivation. To address the influence of tactile deprivation on adult behavior, we performed bilateral whisker trimming in mice for 10 days after birth (BWT10 mice and examined social behaviors, tactile discrimination, and c-Fos expression, a marker of neural activation, in adults after full whisker regrowth. Adult BWT10 mice exhibited significantly shorter crossable distances in the gap-crossing test than age-matched controls, indicating persistent deficits in whisker-dependent tactile perception. In contrast to controls, BWT10 mice exhibited no preference for the social compartment containing a conspecific in the three-chamber test. Furthermore, the development of amygdala circuitry was severely affected in BWT10 mice. Based on the c-Fos expression pattern, hyperactivity was found in BWT10 amygdala circuits for processing fear/anxiety-related responses to height stress but not in circuits for processing reward stimuli during whisker-dependent cued learning. These results demonstrate that neonatal whisker trimming and concomitant whisker-dependent tactile discrimination impairment severely disturbs the development of amygdala-dependent emotional regulation.

Scutellarin Mitigates Aβ-Induced Neurotoxicity and Improves Behavior Impairments in AD Mice

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Yue-Qin Zeng

2018-04-01

Full Text Available Alzheimer’s disease (AD is pathologically characterized by excessive accumulation of amyloid-beta (Aβ within extracellular spaces of the brain. Aggregation of Aβ has been shown to trigger oxidative stress, inflammation, and neurotoxicity resulting in cognitive dysfunction. In this study, we use models of cerebral Aβ amyloidosis to investigate anti-amyloidogenic effects of scutellarin in vitro and in vivo. Our results show that scutellarin, through binding to Aβ42, efficiently inhibits oligomerization as well as fibril formation and reduces Aβ oligomer-induced neuronal toxicity in cell line SH-SY5Y. After nine months of treatment in APP/PS1 double-transgenic mice, scutellarin significantly improves behavior, reduces soluble and insoluble Aβ levels in the brain and plasma, decreases Aβ plaque associated gliosis and levels of proinflammatory cytokines TNF-α and IL-6, attenuates neuroinflammation, displays anti-amyloidogenic effects, and highlights the beneficial effects of intervention on development or progression of AD-like neuropathology.

Size-dependent impairment of cognition in mice caused by the injection of gold nanoparticles

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Chen, Yu-Shiun; Hong, Meng-Yeng; Huang, G Steve; Hung, Yao-Ching; Lin, Li-Wei; Liau, Ian

2010-01-01

We explored the size-dependent impairment of cognition in mice caused by the injection of gold nanoparticles (GNPs). GNPs of 17 and 37 nm in diameter were injected intraperitoneally into BALB/c mice at doses ranging from 0.5 to 14.6 mg kg -1 . ICP-MS was performed on brain tissue collected 1, 14 and 21 days after the injection. A passive-avoidance test was performed on day 21. Monoamine levels were determined on day 21. The microscopic distribution of GNPs in the hippocampus was examined using coherent anti-Stokes Raman scattering (CARS) microscopy and transmission electron microscopy (TEM). The results indicated that 17 nm GNPs passed through the blood-brain barrier more rapidly than 37 nm GNPs. Treatment with 17 nm GNPs decreased the latency time, which was comparable to the effect of scopolamine treatment, while 37 nm GNPs showed no significant effect. Dopamine levels and serotonin levels in the brain were significantly altered by the injection of 17 and 37 nm GNPs. GNPs affected dopaminergic and serotonergic neurons. CARS microscopy indicated that 17 nm GNPs entered the Cornu Ammonis (CA) region of the hippocampus, while 37 nm GNPs were excluded from the CA region. TEM verified the presence of 17 nm GNPs in the cytoplasm of pyramidal cells. In this study, we showed that the ability of GNPs to damage cognition in mice was size-dependent and associated with the ability of the particles to invade the hippocampus. The dosage and duration of the treatment should be taken into account if GNPs are used in the future as vehicles to carry therapeutic agents into the brain.

Size-dependent impairment of cognition in mice caused by the injection of gold nanoparticles

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Chen, Yu-Shiun; Hong, Meng-Yeng; Huang, G Steve [Institute of Nanotechnology, Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 300, Taiwan (China); Hung, Yao-Ching [Section of Gynecologic Oncology, Department of Obstetrics and Gynecology, China Medical University and Hospital, 91 Hsueh Shih Road, Taichung 404, Taiwan (China); Lin, Li-Wei [School of Chinese Medicine for Post-Baccalaureate, I-Shou University, 8 Yida Road, Yanchao Township, Kaohsiung Country 82445, Taiwan (China); Liau, Ian, E-mail: gstevehuang@mail.nctu.edu.tw [Department of Applied Chemistry, National Chiao Tung University, 1001 University Road, Hsinchu 300, Taiwan (China)

2010-12-03

We explored the size-dependent impairment of cognition in mice caused by the injection of gold nanoparticles (GNPs). GNPs of 17 and 37 nm in diameter were injected intraperitoneally into BALB/c mice at doses ranging from 0.5 to 14.6 mg kg{sup -1}. ICP-MS was performed on brain tissue collected 1, 14 and 21 days after the injection. A passive-avoidance test was performed on day 21. Monoamine levels were determined on day 21. The microscopic distribution of GNPs in the hippocampus was examined using coherent anti-Stokes Raman scattering (CARS) microscopy and transmission electron microscopy (TEM). The results indicated that 17 nm GNPs passed through the blood-brain barrier more rapidly than 37 nm GNPs. Treatment with 17 nm GNPs decreased the latency time, which was comparable to the effect of scopolamine treatment, while 37 nm GNPs showed no significant effect. Dopamine levels and serotonin levels in the brain were significantly altered by the injection of 17 and 37 nm GNPs. GNPs affected dopaminergic and serotonergic neurons. CARS microscopy indicated that 17 nm GNPs entered the Cornu Ammonis (CA) region of the hippocampus, while 37 nm GNPs were excluded from the CA region. TEM verified the presence of 17 nm GNPs in the cytoplasm of pyramidal cells. In this study, we showed that the ability of GNPs to damage cognition in mice was size-dependent and associated with the ability of the particles to invade the hippocampus. The dosage and duration of the treatment should be taken into account if GNPs are used in the future as vehicles to carry therapeutic agents into the brain.

Chronic mild stress impairs latent inhibition and induces region-specific neural activation in CHL1-deficient mice, a mouse model of schizophrenia.

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Buhusi, Mona; Obray, Daniel; Guercio, Bret; Bartlett, Mitchell J; Buhusi, Catalin V

2017-08-30

Schizophrenia is a neurodevelopmental disorder characterized by abnormal processing of information and attentional deficits. Schizophrenia has a high genetic component but is precipitated by environmental factors, as proposed by the 'two-hit' theory of schizophrenia. Here we compared latent inhibition as a measure of learning and attention, in CHL1-deficient mice, an animal model of schizophrenia, and their wild-type littermates, under no-stress and chronic mild stress conditions. All unstressed mice as well as the stressed wild-type mice showed latent inhibition. In contrast, CHL1-deficient mice did not show latent inhibition after exposure to chronic stress. Differences in neuronal activation (c-Fos-positive cell counts) were noted in brain regions associated with latent inhibition: Neuronal activation in the prelimbic/infralimbic cortices and the nucleus accumbens shell was affected solely by stress. Neuronal activation in basolateral amygdala and ventral hippocampus was affected independently by stress and genotype. Most importantly, neural activation in nucleus accumbens core was affected by the interaction between stress and genotype. These results provide strong support for a 'two-hit' (genes x environment) effect on latent inhibition in CHL1-deficient mice, and identify CHL1-deficient mice as a model of schizophrenia-like learning and attention impairments. Copyright © 2017 Elsevier B.V. All rights reserved.

Insulin-Independent GABAA Receptor-Mediated Response in the Barrel Cortex of Mice with Impaired Met Activity.

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Lo, Fu-Sun; Erzurumlu, Reha S; Powell, Elizabeth M

2016-03-30

Autism spectrum disorder (ASD) is a neurodevelopmental disorder caused by genetic variants, susceptibility alleles, and environmental perturbations. The autism associated geneMETtyrosine kinase has been implicated in many behavioral domains and endophenotypes of autism, including abnormal neural signaling in human sensory cortex. We investigated somatosensory thalamocortical synaptic communication in mice deficient in Met activity in cortical excitatory neurons to gain insights into aberrant somatosensation characteristic of ASD. The ratio of excitation to inhibition is dramatically increased due to decreased postsynaptic GABAAreceptor-mediated inhibition in the trigeminal thalamocortical pathway of mice lacking active Met in the cerebral cortex. Furthermore, in contrast to wild-type mice, insulin failed to increase GABAAreceptor-mediated response in the barrel cortex of mice with compromised Met signaling. Thus, lacking insulin effects may be a risk factor in ASD pathogenesis. A proposed common cause of neurodevelopmental disorders is an imbalance in excitatory neural transmission, provided by the glutamatergic neurons, and the inhibitory signals from the GABAergic interneurons. Many genes associated with autism spectrum disorders impair synaptic transmission in the expected cell type. Previously, inactivation of the autism-associated Met tyrosine kinase receptor in GABAergic interneurons led to decreased inhibition. In thus report, decreased Met signaling in glutamatergic neurons had no effect on excitation, but decimated inhibition. Further experiments indicate that loss of Met activity downregulates GABAAreceptors on glutamatergic neurons in an insulin independent manner. These data provide a new mechanism for the loss of inhibition and subsequent abnormal excitation/inhibition balance and potential molecular candidates for treatment or prevention. Copyright © 2016 the authors 0270-6474/16/363691-07$15.00/0.

Age-dependent loss of cholinergic neurons in learning and memory-related brain regions and impaired learning in SAMP8 mice with trigeminal nerve damage

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Yifan He; Jihong Zhu; Fang Huang; Liu Qin; Wenguo Fan; Hongwen He

2014-01-01

The tooth belongs to the trigeminal sensory pathway. Dental damage has been associated with impairments in the central nervous system that may be mediated by injury to the trigeminal nerve. In the present study, we investigated the effects of damage to the inferior alveolar nerve, an important peripheral nerve in the trigeminal sensory pathway, on learning and memory be-haviors and structural changes in related brain regions, in a mouse model of Alzheimer’s disease. Inferior alveolar nerve transection or sham surgery was performed in middle-aged (4-month-old) or elderly (7-month-old) senescence-accelerated mouse prone 8 (SAMP8) mice. When the middle-aged mice reached 8 months (middle-aged group 1) or 11 months (middle-aged group 2), and the elderly group reached 11 months, step-down passive avoidance and Y-maze tests of learn-ing and memory were performed, and the cholinergic system was examined in the hippocampus (Nissl staining and acetylcholinesterase histochemistry) and basal forebrain (choline acetyltrans-ferase immunohistochemistry). In the elderly group, animals that underwent nerve transection had fewer pyramidal neurons in the hippocampal CA1 and CA3 regions, fewer cholinergic ifbers in the CA1 and dentate gyrus, and fewer cholinergic neurons in the medial septal nucleus and vertical limb of the diagonal band, compared with sham-operated animals, as well as showing impairments in learning and memory. Conversely, no signiifcant differences in histology or be-havior were observed between middle-aged group 1 or group 2 transected mice and age-matched sham-operated mice. The present ifndings suggest that trigeminal nerve damage in old age, but not middle age, can induce degeneration of the septal-hippocampal cholinergic system and loss of hippocampal pyramidal neurons, and ultimately impair learning ability. Our results highlight the importance of active treatment of trigeminal nerve damage in elderly patients and those with Alzheimer’s disease, and

Distinct motor impairments of dopamine D1 and D2 receptor knockout mice revealed by three types of motor behavior

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Toru eNakamura

2014-07-01

Full Text Available Both D1R and D2R knock out (KO mice of the major dopamine receptors show significant motor impairments. However, there are some discrepant reports, which may be due to the differences in genetic background and experimental procedures. In addition, only few studies directly compared the motor performance of D1R and D2R KO mice. In this paper, we examined the behavioral difference among N10 congenic D1R and D2R KO, and wild type (WT mice. First, we examined spontaneous motor activity in the home cage environment for consecutive five days. Second, we examined motor performance using the rota-rod task, a standard motor task in rodents. Third, we examined motor ability with the Step-Wheel task in which mice were trained to run in a motor-driven turning wheel adjusting their steps on foothold pegs to drink water. The results showed clear differences among the mice of three genotypes in three different types of behavior. In monitoring spontaneous motor activities, D1R and D2R KO mice showed higher and lower 24 h activities, respectively, than WT mice. In the rota-rod tasks, at a low speed, D1R KO mice showed poor performance but later improved, whereas D2R KO mice showed a good performance at early days without further improvement. When first subjected to a high speed task, the D2R KO mice showed poorer rota-rod performance at a low speed than the D1R KO mice. In the Step-Wheel task, across daily sessions, D2R KO mice increased the duration that mice run sufficiently close to the spout to drink water, and decreased time to touch the floor due to missing the peg steps and number of times the wheel was stopped, which performance was much better than that of D1R KO mice. These incongruent results between the two tasks for D1R and D2R KO mice may be due to the differences in the motivation for the rota-rod and Step-Wheel tasks, aversion- and reward-driven, respectively. The Step-Wheel system may become a useful tool for assessing the motor ability of WT

Increased anxiety and fear memory in adult mice lacking type 2 deiodinase.

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Bárez-López, Soledad; Montero-Pedrazuela, Ana; Bosch-García, Daniel; Venero, César; Guadaño-Ferraz, Ana

2017-10-01

A euthyroid state in the brain is crucial for its adequate development and function. Impairments in thyroid hormones (THs; T3 or 3,5,3'-triiodothyronine and T4 or thyroxine) levels and availability in brain can lead to neurological alterations and to psychiatric disorders, particularly mood disorders. The thyroid gland synthetizes mainly T4, which is secreted to circulating blood, however, most actions of THs are mediated by T3, the transcriptionally active form. In the brain, intracellular concentrations of T3 are modulated by the activity of type 2 (D2) and type 3 (D3) deiodinases. In the present work, we evaluated learning and memory capabilities and anxiety-like behavior at adult stages in mice lacking D2 (D2KO) and we analyzed the impact of D2-deficiency on TH content and on the expression of T3-dependent genes in the amygdala and the hippocampus. We found that D2KO mice do not present impairments in spatial learning and memory, but they display emotional alterations with increased anxiety-like behavior as well as enhanced auditory-cued fear memory and spontaneous recovery of fear memory following extinction. D2KO mice also presented reduced T3 content in the hippocampus and decreased expression of the T3-dependent gene Dio3 in the amygdala suggesting a hypothyroid status in this structure. We propose that the emotional dysfunctions found in D2KO mice can arise from the reduced T3 content in their brain, which consequently leads to alterations in gene expression with functional consequences. We found a downregulation in the gene encoding for the calcium-binding protein calretinin (Calb2) in the amygdala of D2KO mice that could affect the GABAergic transmission. The current findings in D2KO mice can provide insight into emotional disorders present in humans with DIO2 polymorphisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Three months of high-fructose feeding fails to induce excessive weight gain or leptin resistance in mice.

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Erik J Tillman

Full Text Available High-fructose diets have been implicated in obesity via impairment of leptin signaling in humans and rodents. We investigated whether fructose-induced leptin resistance in mice could be used to study the metabolic consequences of fructose consumption in humans, particularly in children and adolescents. Male C57Bl/6 mice were weaned to a randomly assigned diet: high fructose, high sucrose, high fat, or control (sugar-free, low-fat. Mice were maintained on their diets for at least 14 weeks. While fructose-fed mice regularly consumed more kcal and expended more energy, there was no difference in body weight compared to control by the end of the study. Additionally, after 14 weeks, both fructose-fed and control mice displayed similar leptin sensitivity. Fructose-feeding also did not change circulating glucose, triglycerides, or free fatty acids. Though fructose has been linked to obesity in several animal models, our data fail to support a role for fructose intake through food lasting 3 months in altering of body weight and leptin signaling in mice. The lack of impact of fructose in the food of growing mice on either body weight or leptin sensitivity over this time frame was surprising, and important information for researchers interested in fructose and body weight regulation.

Diet-induced obesity impairs endometrial stromal cell decidualization: a potential role for impaired autophagy.

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Rhee, Julie S; Saben, Jessica L; Mayer, Allyson L; Schulte, Maureen B; Asghar, Zeenat; Stephens, Claire; Chi, Maggie M-Y; Moley, Kelle H

2016-06-01

What effect does diet-induced obesity have on endometrial stromal cell (ESC) decidualization? Diet-induced obesity impairs ESC decidualization. Decidualization is important for successful implantation and subsequent health of the pregnancy. Compared with normal-weight women, obese women have lower pregnancy rates (both spontaneous and by assisted reproductive technology), higher rates of early pregnancy loss and poorer oocyte quality. Beginning at 6 weeks of age, female C57Bl/6J mice were fed either a high-fat/high-sugar diet (HF/HS; 58% Fat Energy/Sucrose) or a diet of standard mouse chow (CON; 13% Fat) for 12 weeks. At this point, metabolic parameters were measured. Some of the mice (n = 9 HF/HS and 9 CON) were mated with reproductively competent males, and implantation sites were assessed. Other mice (n = 11 HF/HS and 10 CON) were mated with vasectomized males, and artificial decidualization was induced. For in vitro human studies of primary ESCs, endometrial tissue was obtained via biopsy from normo-ovulatory patients without history of infertility (obese = BMI > 30 kg/m(2), n = 11 and lean = BMI treatment with cAMP and medroxyprogesterone. The level of expression of decidualization markers was assessed by RT-qPCR (mRNA) and western blotting (protein). ATP content of ESCs was measured, and levels of autophagy were assessed by western blotting of the autophagy regulators acetyl coa carboxylase (ACC) and ULK1 (Ser 317). Autophagic flux was measured by western blot of the marker LC3b-II. Mice exposed to an HF/HS diet became obese and metabolically impaired. HF/HS-exposed mice mated to reproductively competent males had smaller implantation sites in early pregnancy (P obese women than in those of normal-weight women (Ptreatment abrogated this increase. Many aspects of obesity and metabolic impairment could contribute to the decidualization defects observed in the HF/HS-exposed mice. Although our findings suggest that both autophagy and decidualization are impaired

Essential fatty acid deficiency in mice impairs lactose digestion

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Lukovac, S.; Los, E. L.; Stellaard, F.; Rings, E. H. H. M.; Verkade, H. J.

Essential fatty acid (EFA) deficiency in mice induces fat malabsorption. We previously reported indications that the underlying mechanism is located at the level of the intestinal mucosa. We have investigated the effects of EFA deficiency on small intestinal morphology and function. Mice were fed an

Toxoplasma gondii Infection in Mice Impairs Long-Term Fear Memory Consolidation through Dysfunction of the Cortex and Amygdala.

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Ihara, Fumiaki; Nishimura, Maki; Muroi, Yoshikage; Mahmoud, Motamed Elsayed; Yokoyama, Naoaki; Nagamune, Kisaburo; Nishikawa, Yoshifumi

2016-10-01

Chronic infection with Toxoplasma gondii becomes established in tissues of the central nervous system, where parasites may directly or indirectly modulate neuronal function. Epidemiological studies have revealed that chronic infection in humans is a risk factor for developing mental diseases. However, the mechanisms underlying parasite-induced neuronal dysfunction in the brain remain unclear. Here, we examined memory associated with conditioned fear in mice and found that T. gondii infection impairs consolidation of conditioned fear memory. To examine the brain pathology induced by T. gondii infection, we analyzed the parasite load and histopathological changes. T. gondii infects all brain areas, yet the cortex exhibits more severe tissue damage than other regions. We measured neurotransmitter levels in the cortex and amygdala because these regions are involved in fear memory expression. The levels of dopamine metabolites but not those of dopamine were increased in the cortex of infected mice compared with those in the cortex of uninfected mice. In contrast, serotonin levels were decreased in the amygdala and norepinephrine levels were decreased in the cortex and amygdala of infected mice. The levels of cortical dopamine metabolites were associated with the time spent freezing in the fear-conditioning test. These results suggest that T. gondii infection affects fear memory through dysfunction of the cortex and amygdala. Our findings provide insight into the mechanisms underlying the neurological changes seen during T. gondii infection. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Prenatal NMDA Receptor Antagonism Impaired Proliferation of Neuronal Progenitor, Leading to Fewer Glutamatergic Neurons in the Prefrontal Cortex

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Toriumi, Kazuya; Mouri, Akihiro; Narusawa, Shiho; Aoyama, Yuki; Ikawa, Natsumi; Lu, Lingling; Nagai, Taku; Mamiya, Takayoshi; Kim, Hyoung-Chun; Nabeshima, Toshitaka

2012-01-01

N-methyl--aspartate (NMDA) receptor is a glutamate receptor which has an important role on mammalian brain development. We have reported that prenatal treatment with phencyclidine (PCP), a NMDA receptor antagonist, induces long-lasting behavioral deficits and neurochemical changes. However, the mechanism by which the prenatal antagonism of NMDA receptor affects neurodevelopment, resulting in behavioral deficits, has remained unclear. Here, we report that prenatal NMDA receptor antagonism impaired the proliferation of neuronal progenitors, leading to a decrease in the progenitor pool in the ventricular and the subventricular zone. Furthermore, using a PCR array focused on neurogenesis and neuronal stem cells, we evaluated changes in gene expression causing the impairment of neuronal progenitor proliferation and found aberrant gene expression, such as Notch2 and Ntn1, in prenatal PCP-treated mice. Consequently, the density of glutamatergic neurons in the prefrontal cortex was decreased, probably resulting in glutamatergic hypofunction. Prenatal PCP-treated mice displayed behavioral deficits in cognitive memory and sensorimotor gating until adulthood. These findings suggest that NMDA receptors regulate the proliferation and maturation of progenitor cells for glutamatergic neuron during neurodevelopment, probably via the regulation of gene expression. PMID:22257896

Impaired Autophagy and Defective T Cell Homeostasis in Mice with T Cell-Specific Deletion of Receptor for Activated C Kinase 1

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Guihua Qiu

2017-05-01

Full Text Available Autophagy plays a central role in maintaining T cell homeostasis. Our previous study has shown that hepatocyte-specific deficiency of receptor for activated C kinase 1 (RACK1 leads to lipid accumulation in the liver, accompanied by impaired autophagy, but its in vivo role in T cells remains unclear. Here, we report that mice with T cell-specific deletion of RACK1 exhibit normal intrathymic development of conventional T cells and regulatory T (Treg cells but reduced numbers of peripheral CD4+ and CD8+ T cells. Such defects are cell intrinsic with impaired mitochondrial clearance, increased sensitivity to cell death, and decreased proliferation that could be explained by impaired autophagy. Furthermore, RACK1 is essential for invariant natural T cell development. In vivo, T cell-specific loss of RACK1 dampens concanavalin A-induced acute liver injury. Our data suggest that RACK1 is a key regulator of T cell homeostasis.

TLR2−/− Mice Display Decreased Severity of Giardiasis via Enhanced Proinflammatory Cytokines Production Dependent on AKT Signal Pathway

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Xin Li

2017-09-01

Full Text Available Giardia infection is one of the most common causes of waterborne diarrheal disease in a wide array of mammalian hosts, including humans globally. Although numerous studies have indicated that adaptive immune responses are important for Giardia defense, however, whether the host innate immune system such as TLRs recognizes Giardia remains poorly understood. TLR2 plays a crucial role in pathogen recognition, innate immunity activation, and the eventual pathogen elimination. In this study, we investigated the role of TLR2 as a non-protective inflammatory response on controlling the severity of giardiasis. RT-PCR analysis suggested that TLR2 expression was increased in vitro. We demonstrated that Giardia lamblia-induced cytokines expression by the activation of p38 and ERK pathways via TLR2. Interestingly, the expression of IL-12 p40, TNF-α, and IL-6, but not IFN-γ, was enhanced in TLR2-blocked and TLR2−/− mouse macrophages exposed to G. lamblia trophozoites compared with wild-type (WT mouse macrophages. Further analysis demonstrated that G. lamblia trophozoites reduced cytokines secretion by activating AKT pathway in WT mouse macrophages. Immunohistochemical staining in G. lamblia cysts infected TLR2−/− and WT mice showed that TLR2 was highly expressed in duodenum in infected WT mice. Also, infected TLR2−/− and AKT-blocked mice showed an increased production of IL-12 p40 and IFN-γ compared with infected WT mice at the early stage during infection. Interestingly, infected TLR2−/− and AKT-blocked mice displayed a decreased parasite burden, an increased weight gain rate, and short parasite persistence. Histological morphometry showed shortened villus length, hyperplastic crypt and decreased ratio of villus height/crypt depth in infected WT mice compared with in infected TLR2−/− and AKT-blocked mice. Together, our results suggested that TLR2 deficiency leads to alleviation of giardiasis and reduction of parasite burden through

Ames dwarf (Prop1(df)/Prop1(df)) mice display increased sensitivity of the major GH-signaling pathways in liver and skeletal muscle.

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Miquet, Johanna G; Muñoz, Marina C; Giani, Jorge F; González, Lorena; Dominici, Fernando P; Bartke, Andrzej; Turyn, Daniel; Sotelo, Ana I

2010-04-01

Growth hormone (GH) is an anabolic hormone that regulates growth and metabolism. Ames dwarf mice are natural mutants for Prop1, with impaired development of anterior pituitary and undetectable levels of circulating GH, prolactin and TSH. They constitute an endocrine model of life-long GH-deficiency. The main signaling cascades activated by GH binding to its receptor are the JAK2/STATs, PI-3K/Akt and the MAPK Erk1/2 pathways. We have previously reported that GH-induced STAT5 activation was higher in Ames dwarf mice liver compared to non-dwarf controls. The aim of this study was to evaluate the principal components of the main GH-signaling pathways under GH-deficiency in liver and skeletal muscle, another GH-target tissue. Ames dwarf mice and their non-dwarf siblings were assessed. Animals were injected i.p. with GH or saline 15min before tissue removal. Protein content and phosphorylation of signaling mediators were determined by immunoblotting of tissue solubilizates. GH was able to induce STAT5 and STAT3 tyrosine phosphorylation in both liver and muscle, but the response was higher for Ames dwarf mice than for non-dwarf controls. When Erk1/2 activation was assessed in liver, only dwarf mice showed GH-induced phosphorylation, while in muscle no response to the hormone was found in either genotype. GH-induced Akt phosphorylation at Ser473 in liver was only detected in dwarf mice. In skeletal muscle, both normal and dwarf mice responded to a GH stimulus, although dwarf mice presented higher GH activation levels. The phosphorylation of GSK-3, a substrate of Akt, increased upon hormone stimulation only in dwarf mice in both tissues. In contrast, no differences in the phosphorylation of mTOR, another substrate of Akt, were observed after GH stimulus, either in normal or dwarf mice in liver, while we were unable to determine mTOR in muscle. Protein content of GH-receptor and of the signaling mediators studied did not vary between normal and dwarf animals in the assessed

Syndecan-4 shedding impairs macrovascular angiogenesis in diabetes mellitus

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Li, Ran; Xie, Jun; Wu, Han; Li, Guannan; Chen, Jianzhou; Chen, Qinhua; Wang, Lian; Xu, Biao, E-mail: xubiao@medmail.com.cn

2016-05-20

Purpose: Syndecan-4 (synd4) is a ubiquitous heparan sulfate proteoglycan cell surface receptor that modulates cell proliferation, migration, mechanotransduction, and endocytosis. The extracellular domain of synd4 sheds heavily in acute inflammation, but the shedding of synd4 in chronic inflammation, such as diabetes mellitus (DM), is still undefined. We investigated the alterations of synd4 endothelial expression in DM and the influence of impaired synd4 signaling on angiogenesis in human umbilical vein endothelial cells (HUVECs), diabetic rats, synd4 null mice, and db/db mice. Material and methods: HUVECs were incubated with advanced glycation end products (AGEs). Western blot analysis was used to determine synd4 protein expression and ELISA was used to detect soluble synd4 fragments. The concentration of synd4 in the aortic endothelia of diabetic rats was detected by immunohistochemical staining. Aortic ring assays were performed to study the process of angiogenesis in the diabetic rats and in synd4 null and db/db mice. Recombinant adenoviruses containing the synd4 gene or null were constructed to enhance synd4 aortic expression in db/db mice. Results: Western blot analysis showed decreased expression of the synd4 extracellular domain in HUVECs, and ELISA detected increased soluble fragments of synd4 in the media. Synd4 endothelial expression in the aortas of diabetic rats was decreased. Aortic ring assay indicated impaired angiogenesis in synd4 null and db/db mice, which was partially reversed by synd4 overexpression in db/db mice. Conclusion: Synd4 shedding from vascular endothelial cells played an important role in the diabetes-related impairment of angiogenesis. -- Highlights: •Synd4 shedding from endothelial cells is accelerated under the stimulation of AGEs. •Extracellular domain of synd4 is diminished in the endothelium of DM rats. •Aortic rings of synd4 null mice showed impaired angiogenesis. •Overexpression of synd4 partly rescues macrovascular

Mechanism of impaired regeneration of fatty liver in mouse partial hepatectomy model.

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Murata, Hiroshi; Yagi, Takahito; Iwagaki, Hiromi; Ogino, Tetsuya; Sadamori, Hiroshi; Matsukawa, Hiroyoshi; Umeda, Yuzoh; Haga, Sanae; Takaka, Noriaki; Ozaki, Michitaka

2007-12-01

The mechanism of injury in steatotic liver under pathological conditions been extensively examined. However, the mechanism of an impaired regeneration is still not well understood. The aim of this study was to analyze the mechanism of impaired regeneration of steatotic liver after partial hepatectomy (PH). db/db fatty mice and lean littermates were used for the experiments. Following 70% PH, the survival rate and recovery of liver mass were examined. Liver tissue was histologically examined and analyzed by western blotting and RT-PCR. Of 35 db/db mice, 25 died within 48 h of PH, while all of the control mice survived. Liver regeneration of surviving db/db mice was largely impaired. In db/db mice, mitosis of hepatocytes after PH was disturbed, even though proliferating cell nuclear antigen (PCNA) expression (G1 to S phase marker) in hepatocytes was equally observed in both mice groups. Interestingly, phosphorylation of Cdc2 in db/db mice was suppressed by reduced expression of Wee1 and Myt1, which phosphorylate Cdc2 in S to G2 phase. In steatotic liver, cell-cycle-related proliferative disorders occurred at mid-S phase after PCNA expression. Reduced expression of Wee1 and Myt1 kinases may therefore maintain Cdc2 in an unphosphorylated state and block cell cycle progression in mid-S phase. These kinases may be critical factors involved in the impaired liver regeneration in fatty liver.

Maternal separation induces hippocampal changes in cadherin-1 (CDH-1) mRNA and recognition memory impairment in adolescent mice.

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de Azeredo, Lucas Araújo; Wearick-Silva, Luis Eduardo; Viola, Thiago Wendt; Tractenberg, Saulo Gantes; Centeno-Silva, Anderson; Orso, Rodrigo; Schröder, Nadja; Bredy, Timothy William; Grassi-Oliveira, Rodrigo

2017-05-01

In rodents, disruption of mother-infant attachment induced by maternal separation (MS) is associated with recognition memory impairment and long-term neurobiological consequences. Particularly stress-induced modifications have been associated to disruption of cadherin (CDH) adhesion function, which plays an important role in remodeling of neuronal connection and synaptic plasticity. This study investigated the sex-dependent effect of MS on recognition memory and mRNA levels of classical type I and type II CDH and the related β -catenin (β -Cat) in the hippocampus and prefrontal cortex of late adolescent mice. We provided evidence that the BALB/c mice exposed to MS present deficit in recognition memory, especially females. Postnatal MS induced higher hippocampal CDH-2 and CDH-8 mRNA levels, as well as an upregulation of CDH-1 in the prefrontal cortex in both males and females. MS-reared female mice presented lower CDH-1 mRNA levels in the hippocampus. In addition, hippocampal CDH-1 mRNA levels were positively correlated with recognition memory performance in females. MS-reared male mice exhibited higher β -Cat mRNA levels in the hippocampus. Considering sex-specific effects on CDH mRNA levels, it has been demonstrated mRNA changes in CDH-1, β -Cat, and CDH-6 in the hippocampus, as well as CDH-1, CDH-8 and CDH-11 in the prefrontal cortex. Overall, these findings suggest a complex interplay among MS, CDH mRNA expression, and sex differences in the PFC and hippocampus of adolescent mice. Copyright © 2017 Elsevier Inc. All rights reserved.

Lef1 haploinsufficient mice display a low turnover and low bone mass phenotype in a gender- and age-specific manner.

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Tommy Noh

Full Text Available We investigated the role of Lef1, one of the four transcription factors that transmit Wnt signaling to the genome, in the regulation of bone mass. Microcomputed tomographic analysis of 13- and 17-week-old mice revealed significantly reduced trabecular bone mass in Lef1(+/- females compared to littermate wild-type females. This was attributable to decreased osteoblast activity and bone formation as indicated by histomorphometric analysis of bone remodeling. In contrast to females, bone mass was unaffected by Lef1 haploinsufficiency in males. Similarly, females were substantially more responsive than males to haploinsufficiency in Gsk3beta, a negative regulator of the Wnt pathway, displaying in this case a high bone mass phenotype. Lef1 haploinsufficiency also led to low bone mass in males lacking functional androgen receptor (AR (tfm mutants. The protective skeletal effect of AR against Wnt-related low bone mass is not necessarily a result of direct interaction between the AR and Wnt signaling pathways, because Lef1(+/- female mice had normal bone mass at the age of 34 weeks. Thus, our results indicate an age- and gender-dependent role for Lef1 in regulating bone formation and bone mass in vivo. The resistance to Lef1 haploinsufficiency in males with active AR and in old females could be due to the reduced bone turnover in these mice.

Constitutive stimulatory G protein activity in limb mesenchyme impairs bone growth.

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Karaca, Anara; Malladi, Vijayram Reddy; Zhu, Yan; Tafaj, Olta; Paltrinieri, Elena; Wu, Joy Y; He, Qing; Bastepe, Murat

2018-05-01

GNAS mutations leading to constitutively active stimulatory G protein alpha-subunit (Gsα) cause different tumors, fibrous dysplasia of bone, and McCune-Albright syndrome, which are typically not associated with short stature. Enhanced signaling of the parathyroid hormone/parathyroid hormone-related peptide receptor, which couples to multiple G proteins including Gsα, leads to short bones with delayed endochondral ossification. It has remained unknown whether constitutive Gsα activity also impairs bone growth. Here we generated mice expressing a constitutively active Gsα mutant (Gsα-R201H) conditionally upon Cre recombinase (cGsα R201H mice). Gsα-R201H was expressed in cultured bone marrow stromal cells from cGsα R201H mice upon adenoviral-Cre transduction. When crossed with mice in which Cre is expressed in a tamoxifen-regulatable fashion (CAGGCre-ER™), tamoxifen injection resulted in mosaic expression of the transgene in double mutant offspring. We then crossed the cGsα R201H mice with Prx1-Cre mice, in which Cre is expressed in early limb-bud mesenchyme. The double mutant offspring displayed short limbs at birth, with narrow hypertrophic chondrocyte zones in growth plates and delayed formation of secondary ossification center. Consistent with enhanced Gsα signaling, bone marrow stromal cells from these mice demonstrated increased levels of c-fos mRNA. Our findings indicate that constitutive Gsα activity during limb development disrupts endochondral ossification and bone growth. Given that Gsα haploinsufficiency also leads to short bones, as in patients with Albright's hereditary osteodystrophy, these results suggest that a tight control of Gsα activity is essential for normal growth plate physiology. Copyright © 2018 Elsevier Inc. All rights reserved.

Evaluation of Mobile Phones for Large Display Interaction

OpenAIRE

Bauer, Jens; Thelen, Sebastian; Ebert, Achim

2012-01-01

Large displays have become more and more common in the last few years. While interaction with these displays can be conducted using standard methods such as computer mouse and keyboard, this approach causes issues in multi-user environments, where the various conditions for providing multiple keyboards and mice, together with the facilities to employ them, cannot be met. To solve this problem, interaction using mobile phones was proposed by several authors. Previous solutions were specialized...

Slitrk1-deficient mice display elevated anxiety-like behavior and noradrenergic abnormalities.

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Katayama, K; Yamada, K; Ornthanalai, V G; Inoue, T; Ota, M; Murphy, N P; Aruga, J

2010-02-01

Mutations in SLITRK1 are found in patients with Tourette's syndrome and trichotillomania. SLITRK1 encodes a transmembrane protein containing leucine-rich repeats that is produced predominantly in the nervous system. However, the role of this protein is largely unknown, except that it can modulate neurite outgrowth in vitro. To clarify the role of Slitrk1 in vivo, we developed Slitrk1-knockout mice and analyzed their behavioral and neurochemical phenotypes. Slitrk1-deficient mice exhibited elevated anxiety-like behavior in the elevated plus-maze test as well as increased immobility time in forced swimming and tail suspension tests. Neurochemical analysis revealed that Slitrk1-knockout mice had increased levels of norepinephrine and its metabolite 3-methoxy-4-hydroxyphenylglycol. Administration of clonidine, an alpha2-adrenergic agonist that is frequently used to treat patients with Tourette's syndrome, attenuated the anxiety-like behavior of Slitrk1-deficient mice in the elevated plus-maze test. These results lead us to conclude that noradrenergic mechanisms are involved in the behavioral abnormalities of Slitrk1-deficient mice. Elevated anxiety due to Slitrk1 dysfunction may contribute to the pathogenesis of neuropsychiatric diseases such as Tourette's syndrome and trichotillomania.

Neonatal exposure to polybrominated diphenyl ether (PBDE 153) disrupts spontaneous behaviour, impairs learning and memory, and decreases hippocampal cholinergic receptors in adult mice

International Nuclear Information System (INIS)

Viberg, Henrik; Fredriksson, Anders; Eriksson, Per

2003-01-01

Neonatal exposure to polybrominated diphenyl ether (PBDE 153) disrupts spontaneous behaviour, impairs learning and memory, and decreases hippocampal cholinergic receptors in adult mice. Flame retardants are used to suppress or inhibit combustion processes in an effort to reduce the risk of fire. One class of flame retardants, polybrominated diphenyl ethers (PBDEs), are present and increasing in the environment and in human milk. The present study shows that neonatal exposure to 2,2',4,4',5,5'-hexaBDE (PBDE 153), a PBDE persistent both in environment and in human milk, can induce developmental neurotoxic effects, such as changes in spontaneous behaviour (hyperactivity), impairments in learning and memory, and reduced amounts of nicotinic receptors, effects that get worse with age. Neonatal NMRI male mice were orally exposed on day 10 to 0.45, 0.9, or 9.0 mg of PBDE 153/kg of body weight. Spontaneous behaviour (locomotion, rearing, and total activity) was observed in 2-, 4-, and 6-month-old mice, Morris water maze at an age of 6 months. The behaviour tests showed that the effects were dose-response and time-response related. Animals showing defects in learning and memory also showed significantly reduced amounts of nicotinic receptors in hippocampus, using α-bungarotoxin binding assay. The observed developmental neurotoxic effects seen for PBDE 153 are similar to those seen for PBDE 99 and for certain PCBs. Furthermore, PBDEs appear to as potent as the PCBs

Oral administration of human papillomavirus type 16 E7 displayed on Lactobacillus casei induces E7-specific antitumor effects in C57/BL6 mice.

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Poo, Haryoung; Pyo, Hyun-Mi; Lee, Tae-Young; Yoon, Sun-Woo; Lee, Jong-Soo; Kim, Chul-Joong; Sung, Moon-Hee; Lee, Seung-Hoon

2006-10-01

The mounting of a specific immune response against the human papillomavirus type 16 E7 protein (HPV16 E7) is important for eradication of HPV16 E7-expressing cancer cells from the cervical mucosa. To induce a mucosal immune response by oral delivery of the E7 antigen, we expressed the HPV16 E7 antigen on the surface of Lactobacillus casei by employing a novel display system in which the poly-gamma-glutamic acid (gamma-PGA) synthetase complex A (PgsA) from Bacillus subtilis (chungkookjang) was used as an anchoring motif. After surface expression of the HPV16 E7 protein was confirmed by Western blot, flow cytometry and immunofluorescence microscopy, mice were orally inoculated with L. casei-PgsA-E7. E7-specific serum IgG and mucosal IgA productions were enhanced after oral administration and significantly enhanced after boosting. Systemic and local cellular immunities were significantly increased after boosting, as shown by increased counts of lymphocytes (SI = 9.7 +/- 1.8) and IFN-gamma secreting cells [510 +/- 86 spot-forming cells/10(6)cells] among splenocytes and increased IFN-gamma in supernatants of vaginal lymphocytes. Furthermore, in an E7-based mouse tumor model, animals receiving orally administered L. casei-PgsA-E7 showed reduced tumor size and increased survival rate versus mice receiving control (L. casei-PgsA) immunization. These results collectively indicate that the oral administration of E7 displayed on lactobacillus induces cellular immunity and antitumor effects in mice. Copyright 2006 Wiley-Liss, Inc.

An extensive phenotypic characterization of the hTNFα transgenic mice

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Tugusheva Marina

2007-12-01

Full Text Available Abstract Background Tumor necrosis factor alpha (TNFα is implicated in a wide variety of pathological and physiological processes, including chronic inflammatory conditions, coronary artery disease, diabetes, obesity, and cachexia. Transgenic mice expressing human TNFα (hTNFα have previously been described as a model for progressive rheumatoid arthritis. In this report, we describe extensive characterization of an hTNFα transgenic mouse line. Results In addition to arthritis, these hTNFα transgenic mice demonstrated major alterations in body composition, metabolic rate, leptin levels, response to a high-fat diet, bone mineral density and content, impaired fertility and male sexual function. Many phenotypes displayed an earlier onset and a higher degree of severity in males, pointing towards a significant degree of sexual dimorphism in response to deregulated expression of TNFα. Conclusion These results highlight the potential usefulness of this transgenic model as a resource for studying the progressive effects of constitutively expressed low levels of circulating TNFα, a condition mimicking that observed in a number of human pathological conditions.

CDKL5 knockout leads to altered inhibitory transmission in the cerebellum of adult mice.

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Sivilia, S; Mangano, C; Beggiato, S; Giuliani, A; Torricella, R; Baldassarro, V A; Fernandez, M; Lorenzini, L; Giardino, L; Borelli, A C; Ferraro, L; Calzà, L

2016-06-01

Mutations in the X-linked cyclin-dependent kinase-like 5 gene (CDKL5) are associated to severe neurodevelopmental alterations including motor symptoms. In order to elucidate the neurobiological substrate of motor symptoms in CDKL5 syndrome, we investigated the motor function, GABA and glutamate pathways in the cerebellum of CDKL5 knockout female mice. Behavioural data indicate that CDKL5-KO mice displayed impaired motor coordination on the Rotarod test, and altered steps, as measured by the gait analysis using the CatWalk test. A higher reduction in spontaneous GABA efflux, than that in glutamate, was observed in CDKL5-KO mouse cerebellar synaptosomes, leading to a significant increase of spontaneous glutamate/GABA efflux ratio in these animals. On the contrary, there were no differences between groups in K(+) -evoked GABA and glutamate efflux. The anatomical analysis of cerebellar excitatory and inhibitory pathways showed a selective defect of the GABA-related marker GAD67 in the molecular layer in CDKL5-KO mice, while the glutamatergic marker VGLUT1 was unchanged in the same area. Fine cerebellar structural abnormalities such as a reduction of the inhibitory basket 'net' estimated volume and an increase of the pinceau estimated volume were also observed in CDKL5-KO mice. Finally, the BDNF mRNA expression level in the cerebellum, but not in the hippocampus, was reduced compared with WT animals. These data suggest that CDKL5 deletion during development more markedly impairs the establishment of a correct GABAergic cerebellar network than that of glutamatergic one, leading to the behavioural symptoms associated with CDKL5 mutation. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Corticosterone facilitates extinction of fear memory in BALB/c mice but strengthens cue related fear in C57BL/6 mice.

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Brinks, V; de Kloet, E R; Oitzl, M S

2009-04-01

Corticosterone, the naturally occurring glucocorticoid of rodents is secreted in response to stressors and is known for its facilitating and detrimental effects on emotional learning and memory. The large variability in the action of corticosterone on processing of emotional memories is postulated to depend on genetic background and the spatio-temporal domain in which the hormone operates. To address this hypothesis, mice of two strains with distinct corticosterone secretory patterns and behavioural phenotype (BALB/c and C57BL/6J) were treated with corticosterone (250 microg/kg, i.p.), either 5 min before or directly after acquisition in a fear conditioning task. As the paradigm allowed assessing in one experimental procedure both context- and cue-related fear behaviour, we were able to detect generalization and specificity of fear. BALB/c showed generalized strong fear memory, while C57BL/6J mice discriminated between freezing during context- and cue episodes. Corticosterone had opposite effects on fear memory depending on the strain and time of injection. Corticosterone after acquisition did not affect C57BL/6J mice, but destabilized consolidation and facilitated extinction in BALB/c. Corticosterone 5 min before acquisition strengthened stress-associated signals: BALB/c no longer showed lower fear memory, while C57BL/6J mice displayed increased fear memory and impaired extinction in cue episodes. We propose that corticosterone-induced facilitation of fear memory in C57BL/6J mice can be used to study the development of fear memories, corticosterone administration in BALB/c mice presents a model to examine treatment. We conclude that genetic background and time of corticosterone action are modifiers of fear memory with interesting translational implications for anxiety-related diseases.

C/EBPα Expression is Partially Regulated by C/EBPβ in Response to DNA Damage and C/EBPα Deficient Fibroblasts Display an Impaired G1 Checkpoint

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Ranjan, Rakesh; Thompson, Elizabeth A.; Yoon, Kyungsil; Smart, Robert C.

2009-01-01

We observed that C/EBPα is highly inducible in primary fibroblasts by DNA damaging agents that induce strand breaks, alkylate and crosslink DNA as well as those that produce bulky DNA lesions. Fibroblasts deficient in C/EBPα (C/EBPα-/-) display an impaired G1 checkpoint as evidenced by inappropriate entry into S-phase in response to DNA damage and these cells also display an enhanced G1 to S transition in response to mitogens. The induction of C/EBPα by DNA damage in fibroblasts does not require p53. EMSA analysis of nuclear extracts prepared from UVB- and MNNG-treated fibroblasts revealed increased binding of C/EBPβ to a C/EBP consensus sequence and ChIP analysis revealed increased C/EBPβ binding to the C/EBPα promoter. To determine whether C/EBPβ has a role in the regulation of C/EBPα we treated C/EBPβ-/- fibroblasts with UVB or MNNG. We observed C/EBPα induction was impaired in both UVB- and MNNG- treated C/EBPβ-/- fibroblasts. Our study reveals a novel role for C/EBPβ in the regulation of C/EBPα in response to DNA damage and provides definitive genetic evidence that C/EBPα has a critical role in the DNA damage G1 checkpoint. PMID:19581927

Impaired bone formation in ovariectomized mice reduces implant integration as indicated by longitudinal in vivo micro-computed tomography.

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Li, Zihui; Kuhn, Gisela; Schirmer, Michael; Müller, Ralph; Ruffoni, Davide

2017-01-01

Although osteoporotic bone, with low bone mass and deteriorated bone architecture, provides a less favorable mechanical environment than healthy bone for implant fixation, there is no general agreement on the impact of osteoporosis on peri-implant bone (re)modeling, which is ultimately responsible for the long term stability of the bone-implant system. Here, we inserted an implant in a mouse model mimicking estrogen deficiency-induced bone loss and we monitored with longitudinal in vivo micro-computed tomography the spatio-temporal changes in bone (re)modeling and architecture, considering the separate contributions of trabecular, endocortical and periosteal surfaces. Specifically, 12 week-old C57BL/6J mice underwent OVX/SHM surgery; 9 weeks after we inserted special metal-ceramics implants into the 6th caudal vertebra and we measured bone response with in vivo micro-CT weekly for the following 6 weeks. Our results indicated that ovariectomized mice showed a reduced ability to increase the thickness of the cortical shell close to the implant because of impaired peri-implant bone formation, especially at the periosteal surface. Moreover, we observed that healthy mice had a significantly higher loss of trabecular bone far from the implant than estrogen depleted animals. Such behavior suggests that, in healthy mice, the substantial increase in peri-implant bone formation which rapidly thickened the cortex to secure the implant may raise bone resorption elsewhere and, specifically, in the trabecular network of the same bone but far from the implant. Considering the already deteriorated bone structure of estrogen depleted mice, further bone loss seemed to be hindered. The obtained knowledge on the dynamic response of diseased bone following implant insertion should provide useful guidelines to develop advanced treatments for osteoporotic fracture fixation based on local and selective manipulation of bone turnover in the peri-implant region.

Impaired bone formation in ovariectomized mice reduces implant integration as indicated by longitudinal in vivo micro-computed tomography.

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Zihui Li

Full Text Available Although osteoporotic bone, with low bone mass and deteriorated bone architecture, provides a less favorable mechanical environment than healthy bone for implant fixation, there is no general agreement on the impact of osteoporosis on peri-implant bone (remodeling, which is ultimately responsible for the long term stability of the bone-implant system. Here, we inserted an implant in a mouse model mimicking estrogen deficiency-induced bone loss and we monitored with longitudinal in vivo micro-computed tomography the spatio-temporal changes in bone (remodeling and architecture, considering the separate contributions of trabecular, endocortical and periosteal surfaces. Specifically, 12 week-old C57BL/6J mice underwent OVX/SHM surgery; 9 weeks after we inserted special metal-ceramics implants into the 6th caudal vertebra and we measured bone response with in vivo micro-CT weekly for the following 6 weeks. Our results indicated that ovariectomized mice showed a reduced ability to increase the thickness of the cortical shell close to the implant because of impaired peri-implant bone formation, especially at the periosteal surface. Moreover, we observed that healthy mice had a significantly higher loss of trabecular bone far from the implant than estrogen depleted animals. Such behavior suggests that, in healthy mice, the substantial increase in peri-implant bone formation which rapidly thickened the cortex to secure the implant may raise bone resorption elsewhere and, specifically, in the trabecular network of the same bone but far from the implant. Considering the already deteriorated bone structure of estrogen depleted mice, further bone loss seemed to be hindered. The obtained knowledge on the dynamic response of diseased bone following implant insertion should provide useful guidelines to develop advanced treatments for osteoporotic fracture fixation based on local and selective manipulation of bone turnover in the peri-implant region.

Cyclic GMP-AMP displays mucosal adjuvant activity in mice.

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Ivana Škrnjug

Full Text Available The recently discovered mammalian enzyme cyclic GMP-AMP synthase produces cyclic GMP-AMP (cGAMP after being activated by pathogen-derived cytosolic double stranded DNA. The product can stimulate STING-dependent interferon type I signaling. Here, we explore the efficacy of cGAMP as a mucosal adjuvant in mice. We show that cGAMP can enhance the adaptive immune response to the model antigen ovalbumin. It promotes antigen specific IgG and a balanced Th1/Th2 lymphocyte response in immunized mice. A characteristic of the cGAMP-induced immune response is the slightly reduced induction of interleukin-17 as a hallmark of Th17 activity--a distinct feature that is not observed with other cyclic di-nucleotide adjuvants. We further characterize the innate immune stimulation activity in vitro on murine bone marrow-derived dendritic cells and human dendritic cells. The observed results suggest the consideration of cGAMP as a candidate mucosal adjuvant for human vaccines.

Cyclic GMP-AMP displays mucosal adjuvant activity in mice.

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Škrnjug, Ivana; Guzmán, Carlos Alberto; Rueckert, Christine; Ruecker, Christine

2014-01-01

The recently discovered mammalian enzyme cyclic GMP-AMP synthase produces cyclic GMP-AMP (cGAMP) after being activated by pathogen-derived cytosolic double stranded DNA. The product can stimulate STING-dependent interferon type I signaling. Here, we explore the efficacy of cGAMP as a mucosal adjuvant in mice. We show that cGAMP can enhance the adaptive immune response to the model antigen ovalbumin. It promotes antigen specific IgG and a balanced Th1/Th2 lymphocyte response in immunized mice. A characteristic of the cGAMP-induced immune response is the slightly reduced induction of interleukin-17 as a hallmark of Th17 activity--a distinct feature that is not observed with other cyclic di-nucleotide adjuvants. We further characterize the innate immune stimulation activity in vitro on murine bone marrow-derived dendritic cells and human dendritic cells. The observed results suggest the consideration of cGAMP as a candidate mucosal adjuvant for human vaccines.

Impaired growth of denervated muscle contributes to contracture formation following neonatal brachial plexus injury.

Science.gov (United States)

Nikolaou, Sia; Peterson, Elizabeth; Kim, Annie; Wylie, Christopher; Cornwall, Roger

2011-03-02

The etiology of shoulder and elbow contractures following neonatal brachial plexus injury is incompletely understood. With use of a mouse model, the current study tests the novel hypothesis that reduced growth of denervated muscle contributes to contractures following neonatal brachial plexus injury. Unilateral brachial plexus injuries were created in neonatal mice by supraclavicular C5-C6 nerve root excision. Shoulder and elbow range of motion was measured four weeks after injury. Fibrosis, cross-sectional area, and functional length of the biceps, brachialis, and subscapularis muscles were measured over four weeks following injury. Muscle satellite cells were cultured from denervated and control biceps muscles to assess myogenic capability. In a comparison group, shoulder motion and subscapularis length were assessed following surgical excision of external rotator muscles. Shoulder internal rotation and elbow flexion contractures developed on the involved side within four weeks following brachial plexus injury. Excision of the biceps and brachialis muscles relieved the elbow flexion contractures. The biceps muscles were histologically fibrotic, whereas fatty infiltration predominated in the brachialis and rotator cuff muscles. The biceps and brachialis muscles displayed reduced cross-sectional and longitudinal growth compared with the contralateral muscles. The upper subscapularis muscle similarly displayed reduced longitudinal growth, with the subscapularis shortening correlating with internal rotation contracture. However, excision of the external rotators without brachial plexus injury caused no contractures or subscapularis shortening. Myogenically capable satellite cells were present in denervated biceps muscles despite impaired muscle growth in vivo. Injury of the upper trunk of the brachial plexus leads to impaired growth of the biceps and brachialis muscles, which are responsible for elbow flexion contractures, and impaired growth of the subscapularis

Effects of Early Chemotherapeutic Treatment on Learning in Adolescent Mice: Implications for Cognitive Impairment and Remediation in Childhood Cancer Survivors

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Bisen-Hersh, Emily B.; Hineline, Philip N.; Walker, Ellen A.

2013-01-01

Purpose Among children diagnosed with acute lymphoblastic leukemia (ALL) and given chemotherapy-only treatment, 40-70% of survivors experience neurocognitive impairment. The present study used a preclinical mouse model to investigate the effects of early exposure to common ALL chemotherapeutics methotrexate (MTX) and cytarabine (Ara-C) on learning and memory. Experimental Design Pre-weanling mouse pups were treated on postnatal day (PND) 14, 15, and 16 with saline, MTX, Ara-C, or a combination of MTX and Ara-C. Nineteen days following treatment (PND 35), behavioral tasks measuring different aspects of learning and memory were administered. Results Significant impairment in acquisition and retention over both short (1h) and long (24h) intervals, as measured by autoshaping and novel object recognition tasks, were found following treatment with MTX and Ara-C. Similarly, a novel conditional discrimination task revealed impairment in acquisition for chemotherapy-treated mice. No significant group differences were found following the extensive training component of this task, with impairment following the rapid training component occurring only for the highest MTX and Ara-C combination group. Conclusions Findings are consistent with clinical studies suggesting that childhood cancer survivors are slower at learning new information and primarily exhibit deficits in memory years after successful completion of chemotherapy treatment. The occurrence of mild deficits on a novel conditional discrimination task suggests that chemotherapy-induced cognitive impairment may be ameliorated through extensive training or practice. PMID:23596103

Effects of early chemotherapeutic treatment on learning in adolescent mice: implications for cognitive impairment and remediation in childhood cancer survivors.

Science.gov (United States)

Bisen-Hersh, Emily B; Hineline, Philip N; Walker, Ellen A

2013-06-01

Among children diagnosed with acute lymphoblastic leukemia (ALL) and given chemotherapy-only treatment, 40% to 70% of survivors experience neurocognitive impairment. The present study used a preclinical mouse model to investigate the effects of early exposure to common ALL chemotherapeutics methotrexate (MTX) and cytarabine (Ara-C) on learning and memory. Preweanling mouse pups were treated on postnatal day (PND) 14, 15, and 16 with saline, MTX, Ara-C, or a combination of MTX and Ara-C. Nineteen days after treatment (PND 35), behavioral tasks measuring different aspects of learning and memory were administered. Significant impairment in acquisition and retention over both short (1 hour) and long (24 hours) intervals, as measured by autoshaping and novel object recognition tasks, was found following treatment with MTX and Ara-C. Similarly, a novel conditional discrimination task revealed impairment in acquisition for chemotherapy-treated mice. No significant group differences were found following the extensive training component of this task, with impairment following the rapid training component occurring only for the highest MTX and Ara-C combination group. Findings are consistent with those from clinical studies suggesting that childhood cancer survivors are slower at learning new information and primarily exhibit deficits in memory years after successful completion of chemotherapy. The occurrence of mild deficits on a novel conditional discrimination task suggests that chemotherapy-induced cognitive impairment may be ameliorated through extensive training or practice. ©2013 AACR

Caspase-2 cleavage of tau reversibly impairs memory.

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Zhao, Xiaohui; Kotilinek, Linda A; Smith, Benjamin; Hlynialuk, Chris; Zahs, Kathleen; Ramsden, Martin; Cleary, James; Ashe, Karen H

2016-11-01

In Alzheimer's disease (AD) and other tauopathies, the tau protein forms fibrils, which are believed to be neurotoxic. However, fibrillar tau has been dissociated from neuron death and network dysfunction, suggesting the involvement of nonfibrillar species. Here we describe a novel pathological process in which caspase-2 cleavage of tau at Asp314 impairs cognitive and synaptic function in animal and cellular models of tauopathies by promoting the missorting of tau to dendritic spines. The truncation product, Δtau314, resists fibrillation and is present at higher levels in brains from cognitively impaired mice and humans with AD. The expression of tau mutants that resisted caspase-2 cleavage prevented tau from infiltrating spines, dislocating glutamate receptors and impairing synaptic function in cultured neurons, and it prevented memory deficits and neurodegeneration in mice. Decreasing the levels of caspase-2 restored long-term memory in mice that had existing deficits. Our results suggest an overall treatment strategy for re-establishing synaptic function and restoring memory in patients with AD by preventing tau from accumulating in dendritic spines.

Metabolism of Dopamine in Nucleus Accumbens Astrocytes Is Preserved in Aged Mice Exposed to MPTP

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Brittany M. Winner

2017-12-01

Full Text Available Parkinson disease (PD is prevalent in elderly individuals and is characterized by selective degeneration of nigrostriatal dopamine (NSDA neurons. Interestingly, not all dopamine (DA neurons are affected equally by PD and aging, particularly mesolimbic (ML DA neurons. Here, effects of aging were examined on presynaptic DA synthesis, reuptake, metabolism and neurotoxicant susceptibility of NSDA and mesolimbic dopamine (MLDA neurons and astrocyte DA metabolism. There were no differences in phenotypic markers of DA synthesis, reuptake or metabolism in NSDA or MLDA neurons in aged mice, but MLDA neurons displayed lower DA stores. Astrocyte metabolism of DA to 3-methoxytyramine (3-MT in the striatum was decreased in aged mice, but was maintained in the nucleus accumbens. Despite diminished DA vesicular storage capacity in MLDA neurons, susceptibility to acute neurotoxicant exposure was similar in young and aged mice. These results reveal an age- and neurotoxicant-induced impairment of DA metabolic activity in astrocytes surrounding susceptible NSDA neurons as opposed to maintenance of DA metabolism in astrocytes surrounding resistant MLDA neurons, and suggest a possible therapeutic target for PD.

Postnatal Ablation of Synaptic Retinoic Acid Signaling Impairs Cortical Information Processing and Sensory Discrimination in Mice.

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Park, Esther; Tjia, Michelle; Zuo, Yi; Chen, Lu

2018-06-06

Retinoic acid (RA) and its receptors (RARs) are well established essential transcriptional regulators during embryonic development. Recent findings in cultured neurons identified an independent and critical post-transcriptional role of RA and RARα in the homeostatic regulation of excitatory and inhibitory synaptic transmission in mature neurons. However, the functional relevance of synaptic RA signaling in vivo has not been established. Here, using somatosensory cortex as a model system and the RARα conditional knock-out mouse as a tool, we applied multiple genetic manipulations to delete RARα postnatally in specific populations of cortical neurons, and asked whether synaptic RA signaling observed in cultured neurons is involved in cortical information processing in vivo Indeed, conditional ablation of RARα in mice via a CaMKIIα-Cre or a layer 5-Cre driver line or via somatosensory cortex-specific viral expression of Cre-recombinase impaired whisker-dependent texture discrimination, suggesting a critical requirement of RARα expression in L5 pyramidal neurons of somatosensory cortex for normal tactile sensory processing. Transcranial two-photon imaging revealed a significant increase in dendritic spine elimination on apical dendrites of somatosensory cortical layer 5 pyramidal neurons in these mice. Interestingly, the enhancement of spine elimination is whisker experience-dependent as whisker trimming rescued the spine elimination phenotype. Additionally, experiencing an enriched environment improved texture discrimination in RARα-deficient mice and reduced excessive spine pruning. Thus, RA signaling is essential for normal experience-dependent cortical circuit remodeling and sensory processing. SIGNIFICANCE STATEMENT The importance of synaptic RA signaling has been demonstrated in in vitro studies. However, whether RA signaling mediated by RARα contributes to neural circuit functions in vivo remains largely unknown. In this study, using a RARα conditional

Impairment of the natriuretic peptide system in follitropin receptor knockout mice and reversal by estradiol: implications for obesity-associated hypertension in menopause.

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Belo, Najara O; Sairam, M Ram; Dos Reis, Adelina M

2008-03-01

Estrogen is considered a major regulator of adipose tissue in females. Estrogen increases circulating levels of atrial natriuretic peptide (ANP), a hormone with renal and cardiovascular effects. The aim of this study was to determine the status of the natriuretic peptide system in female follitropin-receptor knockout (FORKO) mice that could be associated with obesity and hypertension observed in these mutants. Furthermore, estradiol treatment was used to reverse alterations observed. FORKO and wild-type (WT) mice received daily injections of estradiol for 4 d. On the fifth day, blood was collected for determination of plasma ANP levels, and selected tissues were collected for determination of ANP, natriuretic peptide receptor type-A (NPR-A) and type-C (NPR-C) gene expression by RT-PCR and binding of [(125)I]ANP by autoradiography. At 5 months of age, FORKO mice were heavier and had more adipose tissue than WT mice. FORKO mice had lower plasma ANP levels and atrial ANP gene expression and higher renal and adipocyte NPR-C gene expression than WT mice. Estradiol treatment reduced weight gain and increased atrial ANP synthesis as well as decreased ANP clearance NPR-C receptors, resulting in elevation of circulating ANP level. In conclusion, this study shows that FORKO females have an impaired natriuretic peptide system, which may contribute to the susceptibility of FORKO mice to developing age-related hypertension previously shown in these animals. This study establishes a relation between estrogen, adipose tissue, and ANP, which may have important implications in menopausal women.

Liver-specific rescuing of CEACAM1 reverses endothelial and cardiovascular abnormalities in male mice with null deletion of Ceacam1 gene

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Lucia Russo

2018-03-01

Full Text Available Objective: Mice with global null mutation of Ceacam1 (Cc1−/−, display impairment of insulin clearance that causes hyperinsulinemia followed by insulin resistance, elevated hepatic de novo lipogenesis, and visceral obesity. In addition, they manifest abnormal vascular permeability and elevated blood pressure. Liver-specific rescuing of Ceacam1 reversed all of the metabolic abnormalities in Cc1−/−liver+ mice. The current study examined whether Cc1−/− male mice develop endothelial and cardiac dysfunction and whether this relates to the metabolic abnormalities caused by defective insulin extraction. Methods and results: Myography studies showed reduction of agonist-stimulated nitric oxide production in resistance arterioles in Cc1−/−, but not Cc1−/−liver+ mice. Liver-based rescuing of CEACAM1 also attenuated the abnormal endothelial adhesiveness to circulating leukocytes in parallel to reducing plasma endothelin-1 and recovering plasma nitric oxide levels. Echocardiography studies revealed increased septal wall thickness, cardiac hypertrophy and reduced cardiac performance in Cc1−/−, but not Cc1−/−xliver+ mice. Insulin signaling experiments indicated compromised IRS1/Akt/eNOS pathway leading to lower nitric oxide level, and activated Shc/MAPK pathway leading to more endothelin-1 production in the aortae and hearts of Cc1−/−, but not Cc1−/−xliver+ mice. The increase in the ratio of endothelin-1 receptor A/B indicated an imbalance in the vasomotor activity of Cc1−/− mice, which was normalized in Cc1−/−xliver+ mice. Conclusions: The data underscore a critical role for impaired CEACAM1-dependent hepatic insulin clearance pathways and resulting hyperinsulinemia and lipid accumulation in aortae and heart in regulating the cardiovascular function. Keywords: Insulin clearance, Hyperinsulinemia, Insulin resistance, Endothelial function, Cardiomyopathy

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