Browsing by Subject "mouse model"
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Item An acetylcholine alpha7 positive allosteric modulator rescues a schizophrenia-associated brain endophenotype in the 15q13.3 microdeletion, encompassing CHRNA7(Elsevier, 2016-07) Gass, Natalia; Weber-Fahr, Wolfgang; Sartorius, Alexander; Becker, Robert; Didriksen, Michael; Stensbøl, Tine Bryan; Bastlund, Jesper Frank; Meyer-Lindenberg, Andreas; Schwarz, Adam J.; Department of Radiology and Imaging Sciences, IU School of MedicineThe 15q13.3 microdeletion copy number variation is strongly associated with schizophrenia and epilepsy. The CHRNA7 gene, encoding nicotinic acetylcholine alpha 7 receptors (nAChA7Rs), is hypothesized to be one of the main genes in this deletion causing the neuropsychiatric phenotype. Here we used a recently developed 15q13.3 microdeletion mouse model to explore whether an established schizophrenia-associated connectivity phenotype is replicated in a murine model, and whether positive modulation of nAChA7 receptor might pharmacologically normalize the connectivity patterns. Resting-state fMRI data were acquired from male mice carrying a hemizygous 15q13.3 microdeletion (N=9) and from wild-type mice (N=9). To study the connectivity profile of 15q13.3 mice and test the effect of nAChA7 positive allosteric modulation, the 15q13.3 mice underwent two imaging sessions, one week apart, receiving a single intraperitoneal injection of either 15 mg/kg Lu AF58801 or saline. The control group comprised wild-type mice treated with saline. We performed seed-based functional connectivity analysis to delineate aberrant connectivity patterns associated with the deletion (15q13.3 mice (saline treatment) versus wild-type mice (saline treatment)) and their modulation by Lu AF58801 (15q13.3 mice (Lu AF58801 treatment) versus 15q13.3 mice (saline treatment)). Compared to wild-type mice, 15q13.3 mice evidenced a predominant hyperconnectivity pattern. The main effect of Lu AF58801 was a normalization of elevated functional connectivity between prefrontal and frontal, hippocampal, striatal, thalamic and auditory regions. The strongest effects were observed in brain regions expressing nAChA7Rs, namely hippocampus, cerebral cortex and thalamus. These effects may underlie the antiepileptic, pro-cognitive and auditory gating deficit-reversal effects of nAChA7R stimulation.Item Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms(ARVO, 2022-02) McDowell, Colleen M.; Kizhatil, Krishnakumar; Elliott, Michael H.; Overby, Darryl R.; Van Batenburg-Sherwood, Joseph; Millar, J. Cameron; Kuehn, Markus H.; Zode, Gulab; Acott, Ted S.; Anderson, Michael G.; Bhattacharya, Sanjoy K.; Bertrand, Jacques A.; Borras, Terete; Bovenkamp, Diane E.; Cheng, Lin; Danias, John; De Ieso, Michael Lucio; Du, Yiqin; Faralli, Jennifer A.; Fuchshofer, Rudolf; Ganapathy, Preethi S.; Gong, Haiyan; Herberg, Samuel; Hernandez, Humberto; Humphries, Peter; John, Simon W. M.; Kaufman, Paul L.; Keller, Kate E.; Kelley, Mary J.; Kelly, Ruth A.; Krizaj, David; Kumar, Ajay; Leonard, Brian C.; Lieberman, Raquel L.; Liton, Paloma; Liu, Yutao; Liu, Katy C.; Lopez, Navita N.; Mao, Weiming; Mavlyutov, Timur; McDonnell, Fiona; McLellan, Gillian J.; Mzyk, Philip; Nartey, Andrews; Pasquale, Louis R.; Patel, Gaurang C.; Pattabiraman, Padmanabhan P.; Peters, Donna M.; Raghunathan, Vijaykrishna; Rao, Ponugoti Vasantha; Rayana, Naga; Raychaudhuri, Urmimala; Reina-Torres, Ester; Ren, Ruiyi; Rhee, Douglas; Chowdhury, Uttio Roy; Samples, John R.; Samples, E. Griffen; Sharif, Najam; Schuman, Joel S.; Sheffield, Val C.; Stevenson, Cooper H.; Soundararajan, Avinash; Subramanian, Preeti; Sugali, Chenna Kesavulu; Sun, Yang; Toris, Carol B.; Torrejon, Karen Y.; Vahabikashi, Amir; Vranka, Janice A.; Wang, Ting; Willoughby, Colin E.; Xin, Chen; Yun, Hongmin; Zhang, Hao F.; Fautsch, Michael P.; Tamm, Ernst R.; Clark, Abbot F.; Ethier, C. Ross; Stamer, W. Daniel; Ophthalmology, School of MedicineDue to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings.Item Developmental Differences and Altered Gene Expression in the Ts65Dn Mouse Model of Down Syndrome(2012-03-20) Billingsley, Cherie Nicole; Roper, Randall J.; Chernoff, Ellen; Belecky-Adams, TeriTrisomy 21 occurs in approximately 1 out of 750 live births and causes brachycephaly, a small oral cavity, a shortened mid-face, and mental impairments in individuals with Down syndrome (DS). Craniofacial dysmorphology occurs in essentially all individuals with trisomy 21 and causes functional difficulties. Mouse models are commonly used to study the etiology of human disorders because of the conserved phenotypes between species. The Ts65Dn Down syndrome mouse model has triplicated homologues for approximately half the genes on human chromosome 21 and exhibits many phenotypes that parallel those found in individuals with DS. Specifically, newborn and adult Ts65Dn mice display similar craniofacial defects as humans with DS. Ts65Dn embryos also exhibit smaller mandibular precursors than their euploid littermates at embryonic day 9.5 (E9.5). Furthermore, Ts65Dn mice exhibit reduced birth weight which suggests a possible generalized delay in overall embryonic growth. Based on previous research at E9.5, it was hypothesized that Ts65Dn E13.5 embryos would have reduced mandibular precursors with altered gene expression. It was also hypothesized that other neural crest derived structures would be reduced in trisomic embryos. Using morphological measurements it was determined that the mandible, Meckel’s cartilage, and hyoid cartilage were significantly reduced in E13.5 trisomic embryos. The tongue was of similar size in trisomic and euploid embryos while cardiac and brain tissue volumes were not significantly different between genotypes. Analysis of total embryonic size at E9.5 and E13.5 revealed smaller trisomic embryos with developmental attenuation that was not related to maternal trisomy. A microarray analysis performed on the mandibular precursor revealed 155 differentially expressed non-trisomic genes. Sox9 was of particular interest for its role in cartilage condensation and endochondral ossification. It was hypothesized that the overexpression of Sox9 in the developing mandible would be localized to Meckel’s and hyoid cartilages. Immunohistochemistry performed on the mandibular precursor confirmed an overexpression of Sox9 in both Meckel’s and the hyoid cartilages. This research provides further insight into the development of trisomic tissues, both neural crest and non-neural crest-derived, and also the specific molecular mechanisms that negatively affect mandibular development in Ts65Dn mice and presumably individuals with Down syndrome.Item Effect of Epigallocatechin-3-gallate on a pattern separation task and hippocampal neurogenesis in a mouse model of Down syndrome(2015) Stringer, Megan Elizabeth; Goodlett, Charles R.; Roper, Randall J.; Neal-Beliveau, Bethany S.; Grahame, Nicholas J.Down syndrome (DS) is caused by three copies of human chromosome 21 (Hsa21) and results in an array of phenotypes including intellectual disability. Ts65Dn mice, the most extensively studied DS model, have three copies of ~50% of the genes on Hsa21 and display many phenotypes associated with DS, including cognitive deficits. DYRK1A is found in three copies in humans with Trisomy 21 and in Ts65Dn mice, and is involved in a number of critical pathways including CNS development and osteoclastogenesis. Epigallocatechin-3-gallate (EGCG), the main polyphenol in green tea, inhibits Dyrk1a activity. We have shown that a three-week EGCG treatment (~10mg/kg/day) during adolescence normalizes skeletal abnormalities in Ts65Dn mice, yet the same dose did not rescue deficits in the Morris water maze spatial learning task (MWM) or novel object recognition (NOR). Others have reported that An EGCG dose of 2-3 mg per day (90mg/ml) improved hippocampal-dependent task deficits in Ts65Dn mice. The current study investigated deficits in a radial arm maze pattern separation task in Ts65Dn mice. Pattern separation requires differentiation between similar memories acquired during learning episodes; distinguishing between these similar memories is thought to depend on distinctive encoding in the hippocampus. Pattern separation has been linked to functional activity of newly generated granule cells in the dentate gyrus. Recent studies in Ts65Dn mice have reported significant reductions in adult hippocampal neurogenesis, and after EGCG treatment, enhanced hippocampal neurogenesis. Thus, it was hypothesized that Ts65Dn mice would be impaired in the pattern separation task, and that EGCG would alleviate the pattern separation deficits seen in trisomic mice, in association with increased adult hippocampal neurogenesis. At weaning, Ts65Dn mice and euploid littermates were randomly assigned to the water control, or EGCG [0.4 mg/mL], with both treatments yielding average daily intakes of ~50 mg/kg/day. Beginning on postnatal day 75, all mice were trained on a radial arm maze-delayed non-matching-to-place pattern separation task. Euploid mice performed significantly better over training than Ts65Dn mice, including better performance at each of the three separations. EGCG did not significantly alleviate the pattern separation deficits in Ts65Dn mice. After the behavioral testing commenced, animals were given ad libitum food access for five days, received a 100mg/kg injection of BrdU, and were perfused two hours later. Coronal sections through the dorsal hippocampus were processed for BrdU labeling, and cells were manually counted throughout the subgranular zone of the dentate gyrus. The euploid controls had significantly more BrdU labeled cells than Ts65Dn mice, however, EGCG does not appear to increase proliferation of the hippocampal neuroprogenitor cells. This is the first report of deficits in Ts65Dn mice on a pattern separation task. To the extent that pattern separation depends on the functional involvement of newly generated neurons in an adult dentate gyrus, this approach in Ts65Dn mice may help identify more targeted pharmacotherapies for cognitive deficits in individuals with DS.Item Effects of 50 mg/kg EGCG Treatment of Ts65Dn Down Syndrome Mice on Novel Object Recognition(Office of the Vice Chancellor for Research, 2016-04-08) Stringer, Megan; Roper, Randall J.; Goodlett, Charles R.; Delgado Taboada, Maria FatimaDown syndrome (DS) is caused by trisomy of chromosome 21, and affects 1/700 live births. DYRK1A, a gene found in three copies in humans with DS and Ts65Dn DS mice, has been linked to alterations in morphology and function of the brain resulting in cognitive impairment. Epigallocatechin-3-gallate (EGCG), an inhibitor of DYRK1A activity, has been proposed as a possible treatment. Using the Ts65Dn DS mouse model, we examined the effects of EGCG treatment on on hippocampal dependent learning and memory using a novel object recognition task (NOR). A previous study analyzing the effects of EGCG at a concentration 30mg/kg/day showed that there was no genotype or treatment effect in the NOR task when treatment is continuous through testing. In this study, the mice were given 50 mg/kg/day EGCG or water via their drinking water starting at 3 weeks of age. The mice were handled two days before testing and then underwent a series of behavioral tests including NOR. They underwent testing at 3 weeks and 7 weeks of treatment. Treatment was continuous throughout behavioral testing. NOR consists of a box with the objects placed diagonally from each other. The mice underwent 3 days of testing with 15 minute sessions per day consisting of habituation, exposure, and test day, all of which were recorded and analyzed to determine time spent exploring novel object in relation to familiar. The amount of time spent at each object was scored by three independent scorers, blind to genotype and treatment. We observed no genotype or treatment effect at either the 3 or 7 week test results, which is consistent with our past results. A higher dose, along with a more sensitive test of recognition memory, may be needed in order to show a treatment effect on the Ts65Dn mice.Item Effects of EGCG treatment on deficits in a radial-arm maze spatial pattern separation task in a Down syndrome mouse model(Office of the Vice Chancellor for Research, 2015-04-17) Stringer, Megan; Stancombe, Kailey; Gainey, Sean; Sheikh, Zahir; Abeysekera, Irushi; Goodlett, Charles R.; Roper, Randall J.Down syndrome (DS) is caused by three copies of human chromosome 21 (Hsa 21) and results in a constellation of phenotypes that include intellectual disability. Ts65Dn mice, the most extensively studied model of DS, have three copies of approximately half the genes on Hsa 21 and display many of the phenotypes associated with DS, including cognitive deficits. DYRK1A is found in three copies in humans with Trisomy 21 and has increased expression in a number of tissues. Dyrk1a is also found in three copies in Ts65Dn mice, and has been shown to be involved in a number of critical pathways including CNS development and osteoclastogenesis. Epigallocatechin-3-gallate (EGCG), the main polyphenol found in green tea, is an inhibitor of Dyrk1a activity. We have previously shown that a three week treatment with EGCG normalizes skeletal abnormalities in Ts65Dn mice. Previous work has found that Ts65Dn mice are significantly impaired in several hippocampal-dependent tasks, including the Morris water maze and novel object recognition. Another hippocampal-dependent process, pattern separation, is the ability to differentiate between similar memories acquired during learning. Distinctive encoding of these similar memories in hippocampal formation is thought to be necessary to distinguish between them. Experimental reductions in adult neurogenesis have produced impairments in pattern separation performance. Given that recent studies in Ts65Dn mice have reported significant reductions in adult hippocampal neurogenesis, we hypothesize that Ts65Dn mice will be impaired in the pattern separation task. Furthermore, we hypothesize that treating Ts65Dn mice with EGCG throughout task learning would improve performance to control levels. A radial arm maze-delayed non-matching-toplace pattern separation task with three different degrees of spatial separation is used. Preliminary data suggests that, in contrast to control mice, Ts65Dn mice do not improve their performance over training.Item Eukaryotic translation initiation factor 5A inhibition alters physiopathology and immune responses in a “humanized” transgenic mouse model of type 1 diabetes(American Physiological Society (APS), 2014-04-01) Imam, Shahnawaz; Mirmira, Raghavendra G.; Jaume, Juan C.; Department of Pediatrics, IU School of MedicineTherapeutic options for treatment of type 1 diabetes (T1D) are still missing. New avenues for immune modulation need to be developed. Here we attempted at altering the diabetes outcome of our humanized model of T1D by inhibiting translation-initiation factor eIF5A hypusination in vivo. Double-transgenic (DQ8-GAD65) mice were immunized with adenoviral vectors carrying GAD65 for diabetes induction. Animals were subsequently treated with deoxyhypusine synthase (DHS) inhibitor GC7 and monitored for diabetes development over time. On one hand, helper CD4+ T cells were clearly affected by the downregulation of the eIF5A not just at the pancreas level but overall. On the other hand, the T regulatory cell component of CD4 responded with activation and proliferation significantly higher than in the non-GC7-treated controls. Female mice seemed to be more susceptible to these effects. All together, our results show for the first time that downregulation of eIF5A through inhibition of DHS altered the physiopathology and observed immune outcome of diabetes in an animal model that closely resembles human T1D. Although the development of diabetes could not be abrogated by DHS inhibition, the immunomodulatory capacity of this approach may supplement other interventions directed at increasing regulation of autoreactive T cells in T1D.Item Fast and slow rates of symptom progression in the transgenic SOD1 murine model of ALS(Office of the Vice Chancellor for Research, 2011-04-08) Haulcomb, Melissa M.; Mesnard, Nichole A.; Sanders, Virginia M.; Jones, Kathryn J.ALS is a disease targeting motoneurons (MN). In the SOD1 mouse model of ALS, an axonal dieback process is initiated during the pre-symptomatic stage where MN axons withdraw from target muscle. We have used facial nerve axotomy, which resembles the axonal die-back response, in pre-symptomatic SOD1 mice to investigate aspects of the disease. Apoptotic and pro-inflammatory gene expression is upregulated in pre-symptomatic SOD1 axotomized facial nuclei in addition to significant SOD1 MN death. Disease progression in symptomatic SOD1 facial nuclei resembles the molecular response initiated by axotomy. MN survival levels in symptomatic SOD1 and axotomized, presymptomatic SOD1 facial nuclei are similar. Therefore, facial nerve axotomy produces a disease onset-like response. The current study used behavioral testing to assess motor function, and revealed two groups of SOD1 mice with differing rates of symptomatic disease progression. The slow progression group had significantly less motor impairments compared to the fast progression group, but no difference in symptom onset was seen. Fast progression group showed higher mRNA levels for genes related to axonal injury. Symptomatic severity in SOD1 mice correlates to the cellular and molecular responses to axonal injury. Therefore, research using treatments to slow disease or extend.Item Inhibition of MEK signaling prevents SARS-CoV2-induced lung damage and improves the survival of infected mice(Wiley, 2022-08-28) Xie, Jingwu; Klemsz, Michael J.; Kacena, Melissa A.; Sandusky, George; Zhang, Xiaoli; Kaplan, Mark H.; Pathology and Laboratory Medicine, School of MedicineCoronavirus disease 2019 (COVID-19) is the illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Over 500 million confirmed cases of COVID-19 have been recorded, with 6 million deaths. Thus, reducing the COVID-19-related medical burden is an unmet need. Despite a vaccine that is successful in preventing COVID-19-caused death, effective medication to relieve COVID-19-associated symptoms and alleviate disease progression is still in high demand. In particular, one in three COVID-19 patients have signs of long COVID syndrome and are termed long haulers. At present, there are no effective ways to treat long haulers. In this study, we determine the effectiveness of inhibiting mitogen-activated protein kinase (MEK) signaling in preventing SARS-CoV-2-induced lung damage in mice. We showed that phosphorylation of extracellular signal-regulated kinase (ERK), a marker for MEK activation, is high in SARS-CoV-2-infected lung tissues of mice and humans. We show that selumetinib, a specific inhibitor of the upstream MEK kinases, reduces cell proliferation, reduces lung damage following SARS-CoV-2 infection, and prolongs the survival of the infected mice. Selumetinib has been approved by the US Food and Drug Administration (FDA) to treat cancer. Further analysis indicates that amphiregulin (AREG), an essential upstream molecule, was upregulated following SARS-CoV-2 infection. Our data suggest that MEK signaling activation represents a target for therapeutic intervention strategies against SARS-CoV-2-induced lung damage and that selumetinib may be repurposed to treat COVID-19.Item Multivariate Concentric Square Field unveils behavioral exploratory categories of locomotor activity in mouse model of Down syndrome(Office of the Vice Chancellor for Research, 2015-04-17) Stancombe, Kailey E.; Goodlett, Charles R.; Stewart, Robert J.; Stringer, Megan; Roper, Randall J.Down Syndrome (DS), trisomy 21(Ts21), is a genetic condition in which a third copy of chromosome 21 is present, and results in neurodevelopmental deficits including intellectual disability. DS has been modeled in mice; Ts65Dn mouse model displays many of the phenotypes associated with DS, including cognitive deficits. We previously studied behavioral phenotypes of Ts65Dn mice and observed significantly increased locomotor activity in a novel arena (an “open field”). In those studies, treatment of the Ts65Dn mice with ~10 mg/kg/day of epigallocatechin-3-gallate (EGCG), a selective inhibitor of the DYRK1A kinase (one of the genes implicated in the neurodevelopmental deficits in DS and in Ts65Dn mice), failed to attenuate hyperactivity. Locomotor activity in an open field is a basic measure of general exploration in a simple environment, and was only moderately sensitive to the hyperactivity of the Ts65Dn mice. The aim of the current study was to use a more advanced analysis of behavioral patterns of exploration in a more complex, multi-partitioned arena, termed the Multivariate Concentric Square Field (MCSF). The advantage of MCSF is that it provides more elaborate measures of exploratory behavior by examining different categories of exploration: general activity, exploratory activity, risk assessment, risk taking and shelter seeking behavior. Trisomic mice and euploid littermates were treated with a continuous high dose (~100 mg/kg/day) of EGCG or water (controls) beginning at weaning. At seven weeks of age, they were tested in the MCSF on two consecutive days. Our current results indicate that Ts65Dn mice displayed more exploratory behavior compared to controls, and the EGCG treatment may have normalized exploratory behavior toward that of controls. Identifying altered patterns of exploratory behavior in the Ts65Dn mouse and the normalizing effects of EGCG treatment may help provide a therapeutic approach to DS.