Project description:prenatal stress response, genetic modification Background: Prenatal stress (PS) exposure has been shown to increase the risk for emotional disorders in later life. Furthermore, the serotonin transporter (5-HTT) genotype is suggested to exert a modulating effect on the association between early life stress and the risk for depression. In the present study, we use a 5-HTT x PS paradigm to investigate whether the effects of PS are dependent upon the 5-HTT genotype. Methods: The effects of PS on cognition, anxiety- and depression-related behaviour were examined using a maternal restraint stress paradigm of PS in C57BL6 wild-type (WT) and heterozygous (+/-) 5-HTT knockout mice. Additionally, in the female offspring, a genome-wide hippocampal gene expression screening was performed. Results: 5-HTT +/- offspring showed enhanced memory performance and signs of reduced anxiety as compared to WT offspring. Conversely, exposure of 5-HTT +/- mice to PS was associated with altered stress-responsivity and increased depressive-like behaviour, particularly in female offspring. Further, 5-HTT genotype, PS and their interaction differentially affected the expression of numerous genes and related pathways within the female hippocampus. Specifically, MAPK and neurotrophin signalling were regulated by both the 5-HTT +/- genotype and PS exposure, whereas cytokine and Wnt signalling were affected in a 5-HTT genotype x PS manner, indicating a gene x environment interaction at the molecular level. Conclusions: The long-term behavioural effects of PS in C57BL6 mice are partly dependent on the 5-HTT genotype. Further, hippocampal gene expression profiles suggest that distinct molecular mechanisms mediate the behavioural effects of the 5-HTT genotype, PS exposure, and their interaction. total samples analysed are 12
Project description:prenatal stress response, genetic modification Background: Prenatal stress (PS) exposure has been shown to increase the risk for emotional disorders in later life. Furthermore, the serotonin transporter (5-HTT) genotype is suggested to exert a modulating effect on the association between early life stress and the risk for depression. In the present study, we use a 5-HTT x PS paradigm to investigate whether the effects of PS are dependent upon the 5-HTT genotype. Methods: The effects of PS on cognition, anxiety- and depression-related behaviour were examined using a maternal restraint stress paradigm of PS in C57BL6 wild-type (WT) and heterozygous (+/-) 5-HTT knockout mice. Additionally, in the female offspring, a genome-wide hippocampal gene expression screening was performed. Results: 5-HTT +/- offspring showed enhanced memory performance and signs of reduced anxiety as compared to WT offspring. Conversely, exposure of 5-HTT +/- mice to PS was associated with altered stress-responsivity and increased depressive-like behaviour, particularly in female offspring. Further, 5-HTT genotype, PS and their interaction differentially affected the expression of numerous genes and related pathways within the female hippocampus. Specifically, MAPK and neurotrophin signalling were regulated by both the 5-HTT +/- genotype and PS exposure, whereas cytokine and Wnt signalling were affected in a 5-HTT genotype x PS manner, indicating a gene x environment interaction at the molecular level. Conclusions: The long-term behavioural effects of PS in C57BL6 mice are partly dependent on the 5-HTT genotype. Further, hippocampal gene expression profiles suggest that distinct molecular mechanisms mediate the behavioural effects of the 5-HTT genotype, PS exposure, and their interaction.
Project description:Huntington's disease (HD) is a debilitating progressive neurodegenerative disorder that has profound effects on an individual's cognitive, motor, and behavioral functions. HD is caused by mutation in the huntingtin (HTT) gene that results in CAG repeat expansion and production of an aggregation-prone polyglutamine-containing protein (mHTT). The expression of mHTT causes selective degeneration, mainly in the striatum and cortex brain regions. Yet, the molecular signatures that underlie their selective sensitization remain incompletely characterized. In HD mouse models, we systematically employed immunopurification-mass spectrometry using HTT antibodies targeting non-overlapping epitopes to capture distinct sub-cellular pools of HTT complexes and postulate domain-specific interactions. We also identified mHTT- and tissue-dependent interactions at different disease stages, which were validated using targeted mass spectrometry and computational analysis of HD genetic modifiers. Among the polyQ-dependent, striatum-enriched interactions, we identified interaction with the mediator complex that results in its altered nuclear-cytoplasmic distribution. Integrating IP-MS data with thermal profiling of the mediator complex in HTT deficient cells supports an interaction interface with the mediator tail domain. Broadly, striatum-enriched HTT interactions highlight calcium homeostasis and ion transport at the synapse as sensitizing molecular signatures.
Project description:The serotonin transporter (5-HTT) gene-linked polymorphic region has been suggested to play a modulatory role in mediating the effects of early-life stress on psychopathology rendering carriers of the low-expression short (s)-allele more vulnerable to environmental adversity in later life. Here we analyzed the effects of prenatal stress (PS), 5-Htt genotype, and an interactin of both on DNA methylation in the hippocampi of female C57BL/6 mice. Here, we applied Methylated DNA ImmunoPrecipitation (MeDIP) in a maternal restraint stress paradigm to perform a global promoter DNA methylation screen: Hippocampal DNA of wild type and 5-Htt +/- mice in stressed and control environments were analyzed to define genotype- (G) and environment-dependent (E) as well as GxE-interactive effects on promoter DNA methylation in the brain region, where marked effects were expected. MeDIP-based promoter DNA methylation screen
Project description:Prenatal adversity or stress can have long-term consequences on developmental trajec-tories and health outcomes. Although the biological mechanisms underlying these effects are poorly understood, epigenetic modifications, such as DNA methylation, have the potential to link early-life environments to alterations in physiological systems, with long-term functional impli-cations. We investigated the consequences of two prenatal insults, prenatal alcohol exposure (PAE) and food-related stress, on DNA methylation profiles of the rat brain during early devel-opment. As these insults can have sex-specific effects on biological outcomes, we analyzed epige-nome-wide DNA methylation patterns in prefrontal cortex, a key brain region involved in cogni-tion, executive function, and behavior, of both males and females. We found sex-dependent and sex-concordant influences of these insults on epigenetic patterns. These alterations occurred in genes and pathways related to brain development and immune function, suggesting that PAE and food-related stress may reprogram neurobiological/physiological systems partly through central epigenetic changes, and may do so in a sex-dependent manner. Such epigenetic changes may re-flect the sex-specific effects of prenatal insults on long-term functional and health outcomes and may have important implications for understanding possible mechanisms underlying fetal alco-hol spectrum disorder and other neurodevelopmental disorders.
Project description:Huntington’s disease is a monogenic disorder, with only one known causative gene, huntingtin (HTT). Expansion of a trinucleotide (CAG) repeat within the HTT gene results in a mutant protein containing polyglutamine (polyQ) stretches. While mutant HTT is the primary driver of cellular degeneration in the brain, the molecular and cellular mechanisms are incompletely understood. To further understand the role of polyQ in disease pathogenesis, we studied the dynamics of HTT protein-protein interactions (PPIs) in the striatum of mice with wild-type (Q20) and mutant (Q140) HTT at pre-symptomatic and manifest HD ages using label-free and isotope-labeled IP-MS approaches. Combining these approaches, we demonstrated that HTT PPI dynamics are distinct in early and later disease phases. Computational analysis pointed to early protein interaction changes involving synaptic transmission and vesicle fusion functions, while later interactions underlie changes in synapse morphogenesis and impact the actin cytoskeletal network.
Project description:The serotonin transporter (5-HTT) gene-linked polymorphic region has been suggested to play a modulatory role in mediating the effects of early-life stress on psychopathology rendering carriers of the low-expression short (s)-allele more vulnerable to environmental adversity in later life. Here we analyzed the effects of prenatal stress (PS), 5-Htt genotype, and an interactin of both on DNA methylation in the hippocampi of female C57BL/6 mice. Here, we applied Methylated DNA ImmunoPrecipitation (MeDIP) in a maternal restraint stress paradigm to perform a global promoter DNA methylation screen: Hippocampal DNA of wild type and 5-Htt +/- mice in stressed and control environments were analyzed to define genotype- (G) and environment-dependent (E) as well as GxE-interactive effects on promoter DNA methylation in the brain region, where marked effects were expected.
Project description:Prenatal exposure to toxic metals is associated with altered placental function and adverse health outcomes. The underlying mechanisms linking in utero toxic metal exposures with later-in-life health remain unclear, though placental inflammation is posited as a potential driver. The aim of this study was to evaluate whether in utero metals presence is associated with sex-specific changes in placental protein expression. We hypothesized that sex-specific patterns of metal-associated placental protein expression would be observed, and metals presence would be positively associated with the altered expression of inflammation-associated pathways Using samples banked from the Extremely Low Gestational Age Newborn Study (ELGAN), umbilical cord tissue samples were analyzed via ICP-MS/MS for trace elements, and placental samples underwent a global untargeted proteomics analysis via LC-MS/MS. This work highlights the linkage between prenatal metals exposure and an altered placental proteome, revealing that metals in cord tissue were associated with largely distinct differences in placental protein expression, in a sexually-dimorphic manner.