Ts1Cje Mouse Research Articles

Reduced REST Expression in Neural Progenitor Cells, Adult Cortex, and Impaired REST Nuclear Translocation in the Prefrontal Cortex of Ts1Cje Mouse Model of Down Syndrome

Reduced REST Expression in Neural Progenitor Cells, Adult Cortex, and Impaired REST Nuclear Translocation in the Prefrontal Cortex of Ts1Cje Mouse Model of Down Syndrome

Visual discrimination and inhibitory control deficits in mouse models of Down syndrome: A pilot study using rodent touchscreen technology.

Several non-verbal cognitive and behavioral tests have been developed to assess learning deficits in humans with Down syndrome (DS). Here we used rodent touchscreen paradigms in adult male mice to investigate visual discrimination (VD) learning and inhibitory control in the Dp(16)1/Yey (C57BL/6J genetic background), Ts65Dn (mixed B6 X C3H genetic background) and Ts1Cje (C57BL/6J genetic background) mouse models of DS. Dp(16)1/Yey and Ts1Cje models did not exhibit motivation or learning deficits during early pre-training, however, Ts1Cje mice showed a significant learning delay after the introduction of the incorrect stimulus (late pre-training), suggesting prefrontal cortex defects in this model. Dp(16)1/Yey and Ts1Cje mice display learning deficits in VD but these deficits were more pronounced in the Dp(16)1/Yey model. Both models also exhibited compulsive behavior and abnormal cortical inhibitory control during Extinction compared to WT littermates. Finally, Ts65Dn mice outperformed WT littermates in pre-training stages by initiating a significantly higher number of trials due to their hyperactive behavior. Both Ts65Dn and WT littermates showed poor performance during late pre-training and were not tested in VD. These studies demonstrate significant learning deficits and compulsive behavior in the Ts1Cje and Dp(16)1/Yey mouse models of DS. They also demonstrate that the mouse genetic background (C57BL/6J vs. mixed B6 X C3H) and the absence of hyperactive behavior are key determinants of successful learning in touchscreen behavioral testing. These data will be used to select the mouse model that best mimics cognitive deficits in humans with DS and evaluate the effects of future therapeutic interventions.

Trib1 promotes the development of acute myeloid leukemia in a Ts1Cje mouse model of Down syndrome.

Trib1 promotes the development of acute myeloid leukemia in a Ts1Cje mouse model of Down syndrome.

Novel insights from fetal and placental phenotyping in 3 mouse models of Down syndrome

In human fetuses with Down syndrome, placental pathology, structural anomalies and growth restriction are present. There is currently a significant lack of information regarding the early life span in mouse models of Down syndrome. The objective of this study was to examine embryonic day 18.5 and placental phenotype in the 3 most common mouse models of Down syndrome (Ts65Dn, Dp(16)1/Yey, Ts1Cje). Based on prenatal and placental phenotyping in 3 mouse models of Down syndrome, we hypothesized that one or more of them would have a similar phenotype to human fetuses with trisomy 21, which would make it the most suitable for in utero treatment studies. Here, C57BL6J/6 female mice were mated to Dp(16)1/Yey and Ts1Cje male mice and Ts65Dn female mice to C57BL/B6Eic3Sn.BLiAF1/J male mice. At embryonic day 18.5, dams were euthanized. Embryos and placentas were examined blindly for weight and size. Embryos were characterized as euploid or trisomic, male or female by polymerase chain reaction. A subset of embryos (34 euploid and 34 trisomic) were examined for malformations. The Ts65Dn mouse model showed the largest differences in fetal growth, brain development, and placental development when comparing euploid and trisomic embryos. For the Dp(16)1/Yey mouse model, genotype did not impact fetal growth, but there were differences in brain and placental development. For the Ts1Cje mouse model, no significant association was found between genotype and fetal growth, brain development, or placental development. Euploid mouse embryos had no congenital anomalies; however, 1 mouse embryo died. Hepatic necrosis was seen in 6 of 12 Dp(16)1/Yey (50%) and 1 of 12 Ts1Cje (8%) mouse embryos; hepatic congestion or inflammation was observed in 3 of 10 Ts65Dn mouse embryos (30%). Renal pelvis dilation was seen in 5 of 12 Dp(16)1/Yey (42%), 5 of 10 Ts65Dn (50%), and 3 of 12 Ts1Cje (25%) mouse embryos. In addition, 1 Ts65Dn mouse embryo and 1 Dp(16)1/Yey mouse embryo had an aortic outflow abnormality. Furthermore, 2 Ts1Cje mouse embryos had ventricular septal defects. Ts65Dn mouse placentas had increased spongiotrophoblast necrosis. Fetal and placental growth showed varying trends across strains. Congenital anomalies were primarily seen in trisomic embryos. The presence of liver abnormalities in all 3 mouse models of Down syndrome (10 of 34 cases) is a novel finding. Renal pelvis dilation was also common (13 of 34 cases). Future research will examine human autopsy material to determine if these findings are relevant to infants with Down syndrome. Differences in placental histology were also observed among strains.

The expression profile of miR-3099 during neural development of Ts1Cje mouse model of Down syndrome

MicroRNA-3099 (miR-3099) plays a crucial role in regulating neuronal differentiation and development of the central nervous system (CNS). The miR-3099 is a pro-neuronal miRNA that promotes neural stem/progenitor cell (NSPC) differentiation into neuronal lineage by suppressing astrogliogenesis. Down syndrome (DS) brain exhibited increased astrogliogenesis and reduced neuronal cell density. The involvement of miR-3099 in the neurodevelopment of DS has not been investigated and potentially responsible for the neurogenic-to-gliogenic shift phenomenon observed in DS brain. To investigate the role of miR-3099 during DS brain development, neural/progenitor cell proliferation and differentiation, we profiled miR-3099 expression level in the Ts1Cje, a mouse model for DS. We analysed the Ts1Cje whole brain at embryonic day (E) 10.5, E14.5 and P1.5, proliferating neurospheres and differentiating neurospheres at 3, 9 and 15 days in vitro (DIV). Expression of miR-3099 in both the developing mouse brain and the differentiating neurosphere was not significantly different between Ts1Cje and wild type controls. In contrast, the expression level of miR-3099 was significantly higher (p<0.05) in proliferating NSPC derived from the Ts1Cje compared to wild-type. Further molecular profiling of NPSC and glial cell markers indicated that the expression of Sox2 (p<0.01) and Gfap (p<0.05) were significantly downregulated in Ts1Cje neurospheres as compared to that of wild type, respectively. While there were no significant differences in Tuj1 and Nestin expression levels between the Ts1Cje and wild type neurospheres, their expression levels were ~3-fold upregulated and ~2.6 downregulated Ts1Cje group, respectively. The findings suggest that dysregulation of miR-3099 affects NSPC lineage commitment as indicated by altered postmitotic neuronal cell markers. Further molecular characterisation and gene expression profiling of other neuronal and glial markers will help refine the analysis of gene-gene interactions underlying the neuropathologies of DS.

Apigenin as a Candidate Prenatal Treatment for Trisomy 21: Effects in Human Amniocytes and the Ts1Cje Mouse Model

Human fetuses with trisomy 21 (T21) have atypical brain development that is apparent sonographically in the second trimester. We hypothesize that by analyzing and integrating dysregulated gene expression and pathways common to humans with Down syndrome (DS) and mouse models we can discover novel targets for prenatal therapy. Here, we tested the safety and efficacy of apigenin, identified with this approach, in both human amniocytes from fetuses with T21 and in the Ts1Cje mouse model. Invitro, T21 cells cultured with apigenin had significantly reduced oxidative stress and improved antioxidant defense response. Invivo, apigenin treatment mixed with chow was administered prenatally to the dams and fed to the pups over their lifetimes. There was no significant increase in birth defects or pup deaths resulting from prenatal apigenin treatment. Apigenin significantly improved several developmental milestones and spatial olfactory memory in Ts1Cje neonates. In addition, we noted sex-specific effects on exploratory behavior and long-term hippocampal memory in adult mice, and males showed significantly more improvement than females. We demonstrated that the therapeutic effects of apigenin are pleiotropic, resulting in decreased oxidative stress, activation of pro-proliferative and pro-neurogenic genes (KI67, Nestin, Sox2, and PAX6), reduction of the pro-inflammatory cytokines INFG, IL1A, and IL12P70 through the inhibition of NFκB signaling, increase of the anti-inflammatory cytokines IL10 and IL12P40, and increased expression of the angiogenic and neurotrophic factors VEGFA and IL7. These studies provide proof of principle that apigenin has multiple therapeutic targets in preclinical models ofDS.

Phenotype microarrays reveal metabolic dysregulations of neurospheres derived from embryonic Ts1Cje mouse model of Down syndrome

Down syndrome (DS), is the most common cause of intellectual disability, and is characterized by defective neurogenesis during perinatal development. To identify metabolic aberrations in early neurogenesis, we profiled neurospheres derived from the embryonic brain of Ts1Cje, a mouse model of Down syndrome. High-throughput phenotypic microarray revealed a significant decrease in utilisation of 17 out of 367 substrates and significantly higher utilisation of 6 substrates in the Ts1Cje neurospheres compared to controls. Specifically, Ts1Cje neurospheres were less efficient in the utilisation of glucose-6-phosphate suggesting a dysregulation in the energy-producing pathway. T Cje neurospheres were significantly smaller in diameter than the controls. Subsequent preliminary study on supplementation with 6-phosphogluconic acid, an intermediate of glucose-6-phosphate metabolism, was able to rescue the Ts1Cje neurosphere size. This study confirmed the perturbed pentose phosphate pathway, contributing to defects observed in Ts1Cje neurospheres. We show for the first time that this comprehensive energetic assay platform facilitates the metabolic characterisation of Ts1Cje cells and confirmed their distinguishable metabolic profiles compared to the controls.

Perturbation of the immune cells and prenatal neurogenesis by the triplication of the Erg gene in mouse models of Down syndrome.

Some mouse models of Down syndrome (DS), including Ts1Cje mice, exhibit impaired prenatal neurogenesis with yet unknown molecular mechanism. To gain insights into the impaired neurogenesis, a transcriptomic and flow cytometry analysis of E14.5 Ts1Cje embryo brain was performed. Our analysis revealed that the neutrophil and monocyte ratios in the CD45-positive hematopoietic cells were relatively increased, in agreement with the altered expression of inflammation/immune-related genes, in Ts1Cje embryonic brain, whereas the relative number of brain macrophages was decreased in comparison to wild-type mice. Similar upregulation of inflammation-associated mRNAs was observed in other DS mouse models, with variable trisomic region lengths. We used genetic manipulation to assess the contribution of Erg, a trisomic gene in these DS models, known to regulation hemato-immune cells. The perturbed proportions of immune cells in Ts1Cje mouse brain were restored in Ts1Cje-Erg+/+/Mld2 mice, which are disomic for functional Erg but otherwise trisomic on a Ts1Cje background. Moreover, the embryonic neurogenesis defects observed in Ts1Cje cortex were reduced in Ts1Cje-Erg+/+/Mld2 embryos. Our findings suggest that Erg gene triplication contributes to the dysregulation of the homeostatic proportion of the populations of immune cells in the embryonic brain and decreased prenatal cortical neurogenesis in the prenatal brain with DS.

Gene and protein expression profiles of JAK-STAT signalling pathway in the developing brain of the Ts1Cje down syndrome mouse model

Aims: The JAK-STAT signalling pathway is one of the key regulators of pro-gliogenesis process during brain development. Down syndrome (DS) individuals, as well as DS mouse models, exhibit an increased number of astrocytes, suggesting an imbalance of neurogenic-to-gliogenic shift attributed to dysregulated JAK-STAT signalling pathway. The gene and protein expression profiles of JAK-STAT pathway members have not been characterised in the DS models. Therefore, we aimed to profile the expression of Jak1, Jak2, Stat1, Stat3 and Stat6 at different stages of brain development in the Ts1Cje mouse model of DS.Methods: Whole brain samples from Ts1Cje and wild-type mice at embryonic day (E)10.5, E15, postnatal day (P)1.5; and embryonic cortex-derived neurospheres were collected for gene and protein expression analysis. Gene expression profiles of three brain regions (cerebral cortex, cerebellum and hippocampus) from Ts1Cje and wild-type mice across four time-points (P1.5, P15, P30 and P84) were also analysed.Results: In the developing mouse brain, none of the Jak/Stat genes were differentially expressed in the Ts1Cje model compared to wild-type mice. However, Western blot analyses indicated that phosphorylated (p)-Jak2, p-Stat3 and p-Stat6 were downregulated in the Ts1Cje model. During the postnatal brain development, Jak/Stat genes showed complex expression patterns, as most of the members were downregulated at different selected time-points. Notably, embryonic cortex-derived neurospheres from Ts1Cje mouse brain expressed lower Stat3 and Stat6 protein compared to the wild-type group.Conclusion: The comprehensive expression profiling of Jak/Stat candidates provides insights on the potential role of the JAK-STAT signalling pathway during abnormal development of the Ts1Cje mouse brains.

Expression Profiling of Notch Signalling Pathway and Gamma-Secretase Activity in the Brain of Ts1Cje Mouse Model of Down Syndrome.

Notch signalling pathway is involved in the proliferation of neural progenitor cells (NPCs), to inhibit neuronal cell commitment and to promote glial cell fate. Notch protein is cleaved by gamma-secretase, a multisubunit transmembrane protein complex that releases the Notch intracellular domain (NICD) and subsequently activates the downstream targets. Down syndrome (DS) individuals exhibit an increased number of glial cells (particularly astrocytes), and reduced number of neurons suggesting the involvement of Notch signalling pathway in the neurogenic-to-gliogenic shift in DS brain. Ts1Cje is a DS mouse model that exhibit similar neuropathology to human DS individuals. To date, the spatiotemporal gene expression of the Notch and gamma-secretase genes have not been characterised in Ts1Cje mouse brain. Understanding the expression pattern of Notch and gamma-secretase genes may provide a better understanding of the underlying mechanism that leads to the shift. Gene expression analysis using RT-qPCR was performed on early embryonic and postnatal development of DS brain. In the developing mouse brain, mRNA expression analysis showed that gamma-secretase members (Psen1, Pen-2, Aph-1b, and Ncstn) were not differentially expressed. Notch2 was found to be downregulated in the developing Ts1Cje brain samples. Postnatal gene expression study showed complex expression patterns and Notch1 and Notch2 genes were found to be significantly downregulated in the hippocampus at postnatal day 30. Results from RT-qPCR analysis from E15.5 neurosphere culture showed an increase of expression of Psen1, and Aph-1b but downregulation of Pen-2 and Ncstn genes. Gamma-secretase activity in Ts1Cje E15.5 neurospheres was significantly increased by fivefold. In summary, the association and the role of Notch and gamma-secretase gene expression throughout development with neurogenic-to-gliogenic shift in Ts1Cje remain undefined and warrant further validation.

Copper accumulation in the brain causes the elevation of oxidative stress and less anxious behavior in Ts1Cje mice, a model of Down syndrome

Elevated oxidative stress (OS) is widely accepted to be involved in the pathogenesis of Down syndrome (DS). However, the mechanisms underlying the elevation of OS in DS are poorly understood. Biometals, in particular copper and iron, play roles in OS. We therefore focused on biometals in the brain with DS. In this study, we analyzed the profile of elements, including biometals, in the brain of Ts1Cje mice, a widely used genetic model of DS. An inductively coupled plasma-mass spectrometry (ICP-MS)-based comparative metallomic/elementomic analysis of Ts1Cje mouse brain revealed a higher level of copper in the hippocampus and cerebral cortex, but not in the striatum, in comparison to wild-type littermates. The expression of the copper transporter CTR1, which is involved in the transport of copper into cells, was decreased in the ependymal cells of Ts1Cje mice, suggesting a decrease in the CTR1-mediated transport of copper into the ependymal cells, which excrete copper into the cerebrospinal fluid. To evaluate the pathological significance of the accumulation of copper in the brain of Ts1Cje mice, we examined the effects of a diet with a low copper content (LoCD) on the elevated lipid peroxidation, the accumulation of hyperphosphorylated tau, and some behavioral anomalies. Reducing the copper concentration in the brain by an LoCD restored the enhanced lipid peroxidation and phosphorylation of tau in the brain and reduced anxiety-like behavior, but not hyperactivity or impaired spatial leaning, in Ts1Cje mice. The findings highlight the reduction of accumulation of copper in the brain may be a novel therapeutic strategy for DS.

Copper accumulation in the brain of Down syndrome model mice and its pathophysiological significance

Down syndrome caused by triplication of human chromosome 21 (HSA21) is the most frequent aneuploidy, resulting in mental retardation, intellectual disability and accelerated aging. Individuals with DS are at an increased risk of developing Alzheimer's disease (AD)-like dementia, with up to 75% of DS people in their 60s developing dementia. Oxidative stress is widely accepted as a mechanism underlying a number of DS symptoms, such as accelerated aging and cognitive decline. Superoxide disumutase 1 (Sod1) and amiloyd precursor protein (App) genes are suggested as the candidate genes in HSA21 underlying the enhanced oxidative stress in individuals with DS. However, we previously demonstrated that the Ts1Cje mouse model, which has a normal copy number of both candidate genes, also shows enhanced oxidative stress, suggesting that triplicated genes other than Sod1 and App likely enhance oxidative stress in the brain of DS people. To identify the molecules with enhanced oxidative stress in Ts1Cje mice, we performed several -omics analyses. Recently, we showed that copper was accumulated in the brain of adult Ts1Cje mice in an analysis using inductively coupled plasma mass spectrometry (ICP-MS), and a low-copper diet was able to improve the elevated levels of copper. The low-copper diet also resolved some anomalies, such as the enhanced oxidative stress, accumulation of phosphorylated tau and low anxiety. These findings suggest that the accumulation of copper in the DS brain may be a therapeutic target for ameliorating a number of abnormal phenotypes in individuals with DS.

Ultrastructural study of sciatic nerve in Ts1Cje mouse model for Down syndrome: an implication of peripheral nerve defects in hypotonia

Trisomy 21 is chromosomal abnormality that occurs as a result of triplication of human chromosome 21 (Hsa21), a condition also known as Down syndrome (DS). Beside the intellectual disability and systems anomalies, motor dysfunction due to hypotonia has also been characterised in individuals with DS and yet, its aetiology remains unclear. Ts1Cje, a mouse model for DS, has a partial trisomy (Mmu16) homology to Hsa21, is widely used for DS research. This study investigated the morphological changes and degree of myelination in sciatic nerves of the Ts1Cje mice using both light and transmission electron microscopes processed images. The result showed no morphological difference in the sciatic nerve between the Ts1Cje and WT mice. The g ratio of the Ts1Cje mice was significantly (P<0.0001) higher compared to that of the WT mice. Two factors are known to determine the g ratio, the axonal diameter and the myeline thickness. There was no significant (P=0.2146) difference in the axonal diameter between the two genotypes. Interestingly, the myeline thickness was significantly (P<0.0001) thinner in nerve fibres of the Ts1Cje mice as compared to that of the WT mice. It is therefore concluded that, the hypomyelination in Ts1Cje mice may affect the conduction velocity which in turn affect their motor activity.

Transcriptomic profiling of skeletal muscle from the Ts1Cje mouse model of Down syndrome suggests dysregulation of trisomic genes associated with neuromuscular junction signaling, oxidative stress and chronic inflammation

Ts1Cje is a mouse model of Down syndrome (DS) with partial triplication of chromosome 16, which encompasses a high number of human chromosome 21 (HSA21) orthologous genes. The mouse model exhibits muscle weakness resembling hypotonia in DS individuals. The effect of extra gene dosages on muscle weakness or hypotonia in Ts1Cje and DS individuals remains unknown. To identify molecular dysregulation of the skeletal muscle, we compared the transcriptomic signatures of soleus and extensor digitorum longus (EDL) muscles between the adult Ts1Cje and disomic littermates. A total of 166 and 262 differentially expressed protein-coding genes (DEGs) were identified in the soleus and EDL muscles, respectively. The partial trisomy of MMU16 in Ts1Cje mice has a greater effect on gene expression in EDL. Top-down clustering analysis of all DEGs for represented functional ontologies revealed 5 functional clusters in soleus associated with signal transduction, development of reproductive system, nucleic acid biosynthesis, protein modification and metabolism as well as regulation of gene expression. On the other hand, only 3 functional clusters were observed for EDL namely neuron and cell development, protein modification and metabolic processes as well as ion transport. A total of 11 selected DEGs were validated using qPCR (disomic DEGs: Mansc1; trisomic DEGs: Itsn1, Rcan1, Synj1, Donson, Dyrk1a, Ifnar1, Ifnar2, Runx1, Sod1 and Tmem50b). The validated DEGs were implicated in neuromuscular junction signalling (Itsn1, Syn1), oxidative stress (Sod1, Runx1) and chronic inflammation processes (Runx1, Rcan1, Ifnar1, Ifnar2). Other validated DEGs have not been well-documented as involved in the skeletal muscle development or function, thus serve as interesting novel candidates for future investigations. To our knowledge, the study was the first attempt to determine the transcriptomic profiles of both soleus and EDL muscles in Ts1Cje mice. It provides new insights on the possible disrupted molecular pathways associated with hypotonia in DS individuals.

Cellular function of satellite cells does not play a role in muscle weakness of adult Ts1Cje mice

Down syndrome (DS) is a genetic condition resulting from triplication of human chromosome (HSA)21. Besides intellectual disability, DS is frequently associated with hypotonia. Satellite cells are the resident cells that provides robust and remarkable regenerative capacity to the skeletal muscles, and its population size has been reported to be disease-associated. However, little is known about the population size of satellite cells in DS and the association of its intrinsic cellular functionality and hypotonia seen in DS. Here, we studied the Ts1Cje mouse, a DS murine model displays the muscle weakness characteristic. Satellite cell populations were immunostained with Pax7 and myonuclei numbers in the Ts1Cje extensor digitorum longus muscle were assessed. Their cellular function was further determined via in vitro assay in high-serum conditioned medium. Subsequently, the in vitro self-renewal, proliferative, and differentiation activities of these myogenic precursor cells were assessed after 24, 48, and 72h using Pax7, MyoD, and Ki67 immunomarkers. Our results showed that the population and functionality of Ts1Cje satellite cell did not differ significantly when compared to the wildtype cells isolated from disomic littermates. In conclusion, our findings indicate that intrinsic cellular functionality of the satellite cells, do not contribute to muscle weakness in Ts1Cje mouse.

Molecular Mechanism Underlying Abnormal Differentiation of Neural Progenitor Cells in the Developing Down Syndrome Brain.

Down syndrome (DS) is caused by trisomy for human chromosome 21. Individuals with DS commonly exhibit mental retardation, which is associated with abnormal brain development. In the neocortex of the DS brain, the density of neurons is markedly reduced, whereas that of astrocytes is increased. Similar to abnormalities seen in DS brains, mouse models of DS show deficits in brain development, and neural progenitor cells that give rise to neurons and glia show dysregulation in their differentiation. These suggest that the dysregulation of progenitor fate choices contributes to alterations in the numbers of neurons and astrocytes in the DS brain. Nevertheless, the molecular basis underlying these defects remains largely unknown. We showed that the overexpression of two human chromosome 21 genes, DYRK1A and DSCR1, contributes to suppressed neuronal differentiation of progenitors in the Ts1Cje mouse model of DS. In addition, the effect of DYRK1A and DSCR1 overexpression on neuronal differentiation is mediated by excessive attenuation of the transcription factor NFATc. Additionally, we demonstrated that an increased dosage of DYRK1A contributes to elevated potential of Ts1Cje progenitors to differentiate into astrocytes and enhanced astrogliogenesis in the Ts1Cje neocortex. Further, we linked the increased dosage of DYRK1A to dysregulation of STAT, a transcription factor critical for astrogliogenesis. Together, our studies identify critical pathways responsible for the proper differentiation of neural progenitors into neurons and astrocytes, with direct implications for the anomalies in brain development observed in DS.

Perinatal Natural History of the Ts1Cje Mouse Model of Down Syndrome: Growth Restriction, Early Mortality, Heart Defects, and Delayed Development.

BackgroundThe Ts1Cje model of Down syndrome is of particular interest for perinatal studies because affected males are fertile. This permits affected pups to be carried in wild-type females, which is similar to human pregnancies. Here we describe the early natural history and growth profiles of Ts1Cje embryos and neonates and determine if heart defects are present in this strain.MethodsPups were studied either on embryonic (E) day 15.5, or from postnatal (P) day 3 through weaning on P21. PCR amplification targeting the neomycin cassette (present in Ts1Cje) and Sry (present in males) was used to analyze pup genotypes and sex ratios. Body weights and lengths, as well as developmental milestones, were recorded in Ts1Cje mice and compared to their wild-type (WT) littermates. Histological evaluations were performed at E15.5 to investigate the presence or absence of heart defects. Pups were divided into two groups: Ts1Cje-I pups survived past weaning and Ts1Cje-II pups died at some point before P21.ResultsTs1Cje mouse embryos showed expected Mendelian ratios (45.8%, n = 66 for Ts1Cje embryos; 54.2%, n = 78 for WT embryos). Histological analysis revealed the presence of ventricular septal defects (VSDs) in 21% of Ts1Cje E15.5 embryos. After weaning, only 28.2% of pups were Ts1Cje (185 Ts1Cje out of 656 total pups generated), with males predominating (male:female ratio of 1.4:1). Among the recovered dead pups (n = 207), Ts1Cje (63.3%, n = 131, p<0.01) genotype was found significantly more often than WT (36.7%, n = 76). Retrospective analysis of Ts1Cje-II (pre-weaning deceased) pups showed that they were growth restricted compared to Ts1Cje-I pups (post-weaning survivors). Growth restriction correlated with statistically significant delays in achieving several neonatal milestones between P3 and P21 compared to Ts1Cje-I (post-weaning survivors) neonates and WT littermates.ConclusionsTs1Cje genotype is not associated with increased early in utero mortality. Cardiac defects, specifically VSDs, are part of the phenotype in this strain. There is increased neonatal mortality in Ts1Cje pups, with sex differences observed. Ts1Cje mice that died in the neonatal period were more likely to be growth restricted and delayed in achieving neonatal developmental milestones.

Disrupted interferon-related molecular networks and the over-expressed Ifnar1 in the brain of adult Ts1Cje mouse model of Down syndrome

Event Abstract Back to Event Disrupted interferon-related molecular networks and the over-expressed Ifnar1 in the brain of adult Ts1Cje mouse model of Down syndrome Kai-Leng Tan1, Han-Chung Lee2, King-Hwa Ling2, Hamish. S. Scott3, Mei-I Lai4, Sharmili Vidyadaran4 and Pike-See Cheah1* 1 Universiti Putra Malaysia, Department of Human Anatomy, Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Malaysia 2 Universiti Putra Malaysia, Department of Biomedical Science, Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Malaysia 3 University of Adelaide, Department of Molecular Pathology, SA Pathology and Centre for Cancer Biology, School of Medicine, Faculty of Health Sciences, Australia 4 Universiti Putra Malaysia, Department of Pathology, Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Malaysia Down syndrome (DS) is a chromosomal disorder resulting from trisomy of human chromosome 21 (HSA21) and all DS individual exhibit cognitive impairment. Ts1Cje mouse model of DS has a triplicated region of mouse chromosome 16 (MMU16) which is homologous to HSA21. Three interferon receptor genes (Ifnar1, Ifnar2 and Ifngr2) are located at the triplicated region in MMU16 and also in HSA21. In this study, we aimed to determine the disrupted molecular networks and the role of the candidate gene in the neurogenic-to-gliogenic shift of Ts1Cje mouse brain. A functional transcriptome analysis was performed on the cerebral cortex, cerebellum and hippocampus of Ts1Cje mice at 4 time-points: postnatal day (P)1, P15, P30 and P84. Functional clustering analysis of the identified 317 differentially expressed genes reported interferon-related signalling networks as the most significantly dysregulated pathway in Ts1Cje postnatal brain. Both Ifnar1 and Stat1 were found over-expressed in P84 Ts1Cje cerebral cortex and cerebellum when compared to wild type littermates through qRT-PCR and western blotting analysis. Subsequently, the role of triplicated Ifnar1 was determined by treating Ifnar1 antagonist on differentiating neural stem cells derived from the SVZ of adult Ts1Cje. The assessment on the antagonistic effect of Ifnar1 antagonist reported successful attenuation on the aberrant Stat1 expression in the Ts1Cje group to an expression level which was similar to the wild type group. Acknowledgements This work was supported by Sciencefund Grant, MOSTI, Malaysia (02-01-04-SF1306) awarded to P-SC; and K-HL was a recipient of the Melbourne International Fee Remission Scholarship and Universiti Putra Malaysia Staff Training Scholarship, and a Adelaide Fees Scholarship International equivalent. K-LT and H-CL were a recipient of Malaysian Ministry of Higher Education MyPhD scholarship. Keywords: Brain, Down Syndrome, Neuroinflammation, molecular genetics, Signalling pathway Conference: 14th Meeting of the Asian-Pacific Society for Neurochemistry, Kuala Lumpur, Malaysia, 27 Aug - 30 Aug, 2016. Presentation Type: Poster Presentation Session Topic: 14th Meeting of the Asian-Pacific Society for Neurochemistry Citation: Tan K, Lee H, Ling K, Scott H, Lai M, Vidyadaran S and Cheah P (2016). Disrupted interferon-related molecular networks and the over-expressed Ifnar1 in the brain of adult Ts1Cje mouse model of Down syndrome. Conference Abstract: 14th Meeting of the Asian-Pacific Society for Neurochemistry. doi: 10.3389/conf.fncel.2016.36.00159 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 04 Aug 2016; Published Online: 11 Aug 2016. * Correspondence: Dr. Pike-See Cheah, Universiti Putra Malaysia, Department of Human Anatomy, Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Serdang, Selangor, Malaysia, cheahpikesee@upm.edu.my Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Kai-Leng Tan Han-Chung Lee King-Hwa Ling Hamish. S. Scott Mei-I Lai Sharmili Vidyadaran Pike-See Cheah Google Kai-Leng Tan Han-Chung Lee King-Hwa Ling Hamish. S. Scott Mei-I Lai Sharmili Vidyadaran Pike-See Cheah Google Scholar Kai-Leng Tan Han-Chung Lee King-Hwa Ling Hamish. S. Scott Mei-I Lai Sharmili Vidyadaran Pike-See Cheah PubMed Kai-Leng Tan Han-Chung Lee King-Hwa Ling Hamish. S. Scott Mei-I Lai Sharmili Vidyadaran Pike-See Cheah Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Gene profiling of skeletal muscles of Ts1Cje mouse model for muscle weakness in Down syndrome

Event Abstract Back to Event Gene profiling of skeletal muscles of Ts1Cje mouse model for muscle weakness in Down syndrome Melody P. Leong1, Usman Bala2, Rozita Rosli1, 3, Pike See Cheah2, 3 and King-Hwa Ling1, 3* 1 Universiti Putra Malaysia, Department of Biomedical Science, Faculty of Medicine and Health Sciences, Malaysia 2 Universiti Putra Malaysia, Department of Human Anatomy, Faculty of Medicine and Health Sciences, Malaysia 3 Universiti Putra Malaysia, Genetics & Regenerative Medicine Research Centre (GRMRC); Faculty of Medicine and Health Sciences, Malaysia Down Syndrome (DS) is a chromosomal condition characterised by human chromosome 21 (HSA21) with DS critical region located on the chromosome 21q22. Deficit in motor functions throughout development such as muscle weakness, delayed acquisition of postural control and poor balance are among some of the phenotypes linked to DS. Determination of differentially expressed genes (DEGs) potentially contributing to disruption of molecular pathways of the skeletal muscle could help further understanding of how the additional gene dosage may affect muscle development and function in DS. Ts1Cje is a DS mouse model with partial trisomy for a region of MMU16, encompassing a high number of HSA21 orthologous genes. Ts1Cje was also characterized with muscle weakness that is similar to individuals with DS. In this study, the soleus and extensor digitorum longus (EDL) muscles were harvested from both Ts1Cje and disomic control mice. The gene profile of the samples were analysed and compared using Agilent microarray platform and bioinformatics analyses. Results showed a total of 166 DEGs found in soleus muscles with 37 of them located on MMU16 and a total of 262 DEGs found in EDL muscles with 13 of them located on MMU16 (p-value = 0.05, absolute fold change = 1.5). Nine genes found to be differently expressed in both soleus and EDL muscles were further validated with quantitative reverse transcription PCR (RT-qPCR). The genes were Cdk13, Mansc1, Ifnar1, Ifnar2, Donson, Dyrk1a, Runx1, Sod1, and Tmem50b with the later 5 being genes located on the triplicated region of MMU16 in Ts1Cje mice. Results from the microarray analysis were reflected by RT-qPCR where these genes were differentially upregulated in Ts1Cje mice except Cdk13, which was downregulated instead. Further investigation on the role of these genes at the protein level may provide insight on the underlying mechanism responsible for muscle weakness in Ts1Cje. Acknowledgements The study was supported by Malaysian Ministry of Higher Education's Fundamental Research Grant Scheme awarded to P.-S. Cheah (FRGS/1/2015/SKK08/UPM/02/1) and Malaysian Ministry of Science, Technology and Innovation's Sciencefund grant awarded to K.-H. Ling (02-01-04-SF2336). Keywords: Down Syndrome, Gene Expression, skeletal muscle, in vivo, hypotonia Conference: 14th Meeting of the Asian-Pacific Society for Neurochemistry, Kuala Lumpur, Malaysia, 27 Aug - 30 Aug, 2016. Presentation Type: Poster Presentation Session Topic: 14th Meeting of the Asian-Pacific Society for Neurochemistry Citation: Leong MP, Bala U, Rosli R, Cheah P and Ling K (2016). Gene profiling of skeletal muscles of Ts1Cje mouse model for muscle weakness in Down syndrome. Conference Abstract: 14th Meeting of the Asian-Pacific Society for Neurochemistry. doi: 10.3389/conf.fncel.2016.36.00131 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 04 Aug 2016; Published Online: 11 Aug 2016. * Correspondence: Dr. King-Hwa Ling, Universiti Putra Malaysia, Department of Biomedical Science, Faculty of Medicine and Health Sciences, Serdang, Selangor, 43400, Malaysia, lkh@upm.edu.my Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Melody P Leong Usman Bala Rozita Rosli Pike See Cheah King-Hwa Ling Google Melody P Leong Usman Bala Rozita Rosli Pike See Cheah King-Hwa Ling Google Scholar Melody P Leong Usman Bala Rozita Rosli Pike See Cheah King-Hwa Ling PubMed Melody P Leong Usman Bala Rozita Rosli Pike See Cheah King-Hwa Ling Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Characterisation of gamma-secretase role in the neurogenic-gliogenic shift in Ts1Cje mouse model of Down syndrome

Event Abstract Back to Event Characterisation of gamma-secretase role in the neurogenic-gliogenic shift in Ts1Cje mouse model of Down syndrome Hadri H. Yusof1, 2, Han C. Lee1, 2, De M. Chau2, Pike S. Cheah1, 3 and King-Hwa Ling1, 2* 1 Genetics & Regenerative Medicine Research Centre (GRMRC), Neurobiology and Genetics Group, Malaysia 2 Universiti Putra Malaysia, Medical Genetics Unit, Department of Biomedical Sciences, Faculty of Medical and Health Sciences, Malaysia 3 Universiti Putra Malaysia, Department of Human Anatomy, Faculty of Medicine and Health Sciences, Malaysia Down syndrome (DS) is a disorder caused by an extra copy of chromosome 21 that increases expression of genes located on chromosome 21. This leads to a cascade of direct or indirect effect to the development of the foetal structure and subsequently alters their behaviour during the lifespan. DS is also characterised by the cardinal neurogenic-to-gliogenic shift during neurogenesis and cell-fate determination. To understand the underlying mechanism responsible for the shift, we utilised a mouse model for DS known as Ts1Cje, which also demonstrates the off-balance cellular shift in the brain. Notch-1 mediated signalling pathway is crucial for mammalian CNS development via maintenance of neural stem cell (progenitor) state and inhibition of neuronal commitment and promotion of glial cell fates. The components of gamma-secretase complex (PSEN, NCSTN, Aph-1b and PSENEN) are required for Notch protein cleavage and have link to neurogenesis and gliogenesis in the brain. We aim to profile the spatio-temporal gene expression patterns of gamma-secretase complexes and its primary downstream/upstream components and its effects in neurogenic-gliogenic shift using Ts1Cje mouse model. A total of 72 RNA samples from P1.5, P15, P30 and P84 cerebral cortices, cerebella and hippocampi from the brain of Ts1Cje and disomic mice were collected and converted into cDNA samples. These samples from different region were screened for gene expression study. The expression level of gamma-secretase complexes (PSEN1, NCSTN, Aph-1b, PSENEN) and also the Notch signalling proteins (Notch-1, Notch-2) were analysed using real-time quantitative PCR (qPCR). Preliminary results show no alterations in the expression level of the selected genes between the Ts1Cje and disomic mouse groups. This might be due to the heterogeneity of the cell population in the brain. Further expression study through in vitro neurosphere culture might give us a better insight of the real genetic expression. Acknowledgements The study was supported by Malaysian Ministry of Higher Education's Fundamental Research Grant Scheme awarded to P.-S. Cheah (FRGS/1/2015/SKK08/UPM/02/1) and Malaysian Ministry of Science, Technology and Innovation's Sciencefund grant awarded to K.-H. Ling (02-01-04-SF2336). Keywords: Down Syndrome, Gene Expression, gamma-secretase, Neurogenic, gliogenic Conference: 14th Meeting of the Asian-Pacific Society for Neurochemistry, Kuala Lumpur, Malaysia, 27 Aug - 30 Aug, 2016. Presentation Type: Poster Presentation Session Topic: 14th Meeting of the Asian-Pacific Society for Neurochemistry Citation: Yusof HH, Lee HC, Chau DM, Cheah PS and Ling K (2016). Characterisation of gamma-secretase role in the neurogenic-gliogenic shift in Ts1Cje mouse model of Down syndrome. Conference Abstract: 14th Meeting of the Asian-Pacific Society for Neurochemistry. doi: 10.3389/conf.fncel.2016.36.00161 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 04 Aug 2016; Published Online: 11 Aug 2016. * Correspondence: Dr. King-Hwa Ling, Genetics & Regenerative Medicine Research Centre (GRMRC), Neurobiology and Genetics Group, UPM Serdang, Selangor, Malaysia, lkh@upm.edu.my Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Hadri H Yusof Han C Lee De M Chau Pike S Cheah King-Hwa Ling Google Hadri H Yusof Han C Lee De M Chau Pike S Cheah King-Hwa Ling Google Scholar Hadri H Yusof Han C Lee De M Chau Pike S Cheah King-Hwa Ling PubMed Hadri H Yusof Han C Lee De M Chau Pike S Cheah King-Hwa Ling Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.