Molecular and Cellular Neuroscience Commons^™

Mushroom Body-Specific Gene Regulation By The Swi/Snf Chromatin Remodeling Complex, Kevin Cj Nixon

Electronic Thesis and Dissertation Repository

Over the lifetime of an organism, neurons must establish, remodel, and maintain precise connections in order to form neural circuits that are required for proper nervous system functioning. Disruptions in these processes can lead to neurodevelopmental disorders such as intellectual disability (ID) and autism spectrum disorder. Mutations in genes encoding subunits of the SWI/SNF chromatin remodeling complex have been implicated in ID, yet the role of this complex in neurons is poorly understood. In this project, I established cell-type specific methods to examine the effect of SWI/SNF subunit knockdowns on gene transcription and chromatin structure in the memory-forming neurons of …

Behavioural And Molecular Consequences Of Postnatal Stress In A Mouse Model Of Fetal Alcohol Spectrum Disorder, Bonnie Alberry

Electronic Thesis and Dissertation Repository

Fetal alcohol spectrum disorders (FASD) are caused by prenatal alcohol exposure (PAE) and affect 1‑5% of the North American population. Children born with FASD often face maternal separation throughout childhood. How this early life stress (ELS) affects the severity of FASD-related deficits is poorly understood. Using a mouse model, this dissertation establishes that behavioural deficits accumulate following prenatal alcohol exposure and early life stress, assessed using tests for activity, anxiety-like behaviour as well as learning and memory. Hippocampal gene expression was evaluated using RNA-seq followed by clustering of expression profiles through weighted gene co-expression network analysis (WGCNA). A set of …

Epigenetic Alterations At Synaptic Plasticity Genes In A Genetically Heterogeneous Rat Model Of Neuropsychiatric Disorders, Doan M. On

Theses and Dissertations

Sensorimotor gating impairments are observed across a range of neuropsychiatric conditions. The prepulse inhibition of the acoustic startle response (PPI) is a validated measure of sensorimotor gating. Genetic and pharmacological manipulations in rodents have shown PPI is regulated by specific brain monoaminergic systems. Using genetically heterogeneous NIH-HS rats, we stratified individuals by %PPI. In low PPI animals, we observed elevated mRNA levels of certain neurotransmitter receptors, including metabotropic glutamate receptor Grm2, dopamine receptors Drd1 and Drd2, serotonin receptors Htr1a and Htr2a, and scaffolding protein Homer1, in the frontal cortex (FC) and striatum (STR). We found Drd2 …

Rejuvenation Of The Epigenetic Landscape Of The Aged Brain Through Manipulation Of Circulating Factors, Edward Koellhoffer

Dissertations & Theses (Open Access)

The aging population of the United States is expanding at an alarming rate. The Center for Disease Control and Prevention estimates that the population of those age 65 years and older will reach over 50 million by 2020 and will double to 100 million by 2060. This will not only put a massive strain on national healthcare resources, but will also increase the number of those who are not able to live and function independently. It is becoming increasingly vital to understand how the brain changes with age and mechanisms to possibly protect and rejuvenate the aged brain to a …

The Role Of Ash1l During Human Neurodevelopment, Anna Bagnell

Senior Theses

Autism spectrum disorders (ASD) are associated with defects in neuronal connectivity and are highly heritable. A significant proportion of ASD cases are of complex genetic etiology; complexity which might reflect the impact of gene-environment interactions. However, there is a gap in our understanding of the mechanisms that underlie the gene-environment interaction in autism complex etiology. Genome wide association studies in large ASD cohorts identified high risk variants associated with autism in genes that regulate histone modifications and remodel chromatin. These findings highlight the relevance of chromatin regulatory mechanisms in the pathology of ASD. Changes in Histone H3 methylation have been …

The Role Of H3k4 Methyltransferases In Drosophila Memory, Nicholas Raun

Electronic Thesis and Dissertation Repository

Gene transcription required for long-term memory requires the modification of histones. However, there are still many uncertainties about the identity and spatial expression of genes regulated by histone modifications during memory related processes. In this project I examined the role of Drosophila melanogaster methyltransferases Set1 and trx in courtship memory. Genetic knockdown of Set1 and trx in the mushroom body (MB) revealed that Set1 was necessary for short- and long-term memory, while trx was only required for long-term memory. Transcriptional profiling of MBs following trx-knockdown revealed expression changes in MB-enriched genes and genes involved in RNA processing. Among the …

Single-Base Resolution Mapping Of 5-Hydroxymethylcytosine Modifications In Hippocampus Of Alzheimer's Disease Subjects, Elizabeth M. Ellison, Melissa A. Bradley-Whitman, Mark A. Lovell

Chemistry Faculty Publications

Epigenetic modifications to cytosine have been shown to regulate transcription in cancer, embryonic development, and recently neurodegeneration. While cytosine methylation studies are now common in neurodegenerative research, hydroxymethylation studies are rare, particularly genome-wide mapping studies. As an initial study to analyze 5-hydroxymethylcytosine (5-hmC) in the Alzheimer’s disease (AD) genome, reduced representation hydroxymethylation profiling (RRHP) was used to analyze more than 2 million sites of possible modification in hippocampal DNA of sporadic AD and normal control subjects. Genes with differentially hydroxymethylated regions were filtered based on previously published microarray data for altered gene expression in hippocampal DNA of AD subjects. Our …

Overlapping Signatures Of Chronic Pain In The Dna Methylation Landscape Of Prefrontal Cortex And Peripheral T Cells, Renaud Massart, Sergiy Dymov, Magali Millecamps, Matthew Suderman, Stephanie Gregoire, Kevin Koenigs, Sebastian Alvarado, Maral Tajerian, Laura S. Stone, Moshe Szyf

Publications and Research

We tested the hypothesis that epigenetic mechanisms in the brain and the immune system are associated with chronic pain. Genome-wide DNA methylation assessed in 9 months post nerve-injury (SNI) and Sham rats, in the prefrontal cortex (PFC) as well as in T cells revealed a vast difference in the DNA methylation landscape in the brain between the groups and a remarkable overlap (72%) between differentially methylated probes in T cells and prefrontal cortex. DNA methylation states in the PFC showed robust correlation with pain score of animals in several genes involved in pain. Finally, only 11 differentially methylated probes in …

An Epigenetic Hypothesis For The Genomic Memory Of Pain, Sebastian Alvarado, Maral Tajerian, Matthew Suderman, Ziv Machnes, Stephanie Pierfelice, Magali Millecamps, Laura S. Stone, Moshe Szyf

Publications and Research

Chronic pain is accompanied with long-term sensory, affective and cognitive disturbances. What are the mechanisms that mediate the long-term consequences of painful experiences and embed them in the genome? We hypothesize that alterations in DNA methylation, an enzymatic covalent modification of cytosine bases in DNA,serve as a “genomic” memory of pain in the adult cortex. DNA methylation is an epigenetic mechanism for long-term regulation of gene expression. Neuronal plasticity at the neuroanatomical, functional, morphological, physiological and molecular levels has been demonstrated throughout the neuroaxis in response to persistent pain, including in the adult prefrontal cortex (PFC). We have previously reported …

Polychlorinated Biphenyl Exposure Alters Oxytocin Receptor Gene Expression And Maternal Behavior In Rat, Howard Cromwell

Howard Casey Cromwell

Polychlorinated biphenyl (PCB) is a persistent organic pollutant known to induce diverse molecular and behavioral alterations. Effects of PCB exposure could be transmitted to future generations via changes in behavior and gene expression. Previous work has shown that PCB-exposure can alter social behavior. The present study extends this work by examining a possible molecular mechanism for these changes. Pregnant rats (Sprague-Dawley) were exposed through diet to a combination of non-coplanar (PCB 47 - 2,20,4,40-tetrachlorobiphenyl) and coplanar (PCB 77 - 3,30,4,40- tetrachlorobiphenyl) congeners. Maternal care behaviors were examined by evaluating the rate and quality of nest building on the last 4 …

Understanding Ten-Eleven Translocation-2 In Hematological And Nervous Systems, Feng Pan

FIU Electronic Theses and Dissertations

I proposed the study of two distinct aspects of Ten-Eleven Translocation 2 (TET2) protein for understanding specific functions in different body systems.

In Part I, I characterized the molecular mechanisms of Tet2 in the hematological system. As the second member of Ten-Eleven Translocation protein family, TET2 is frequently mutated in leukemic patients. Previous studies have shown that the TET2 mutations frequently occur in 20% myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN), 10% T-cell lymphoma leukemia and 2% B-cell lymphoma leukemia. Genetic mouse models also display distinct phenotypes of various types of hematological malignancies. I performed 5-hydroxymethylcytosine (5hmC) chromatin immunoprecipitation sequencing (ChIP-Seq) and RNA …

Definition Of The Landscape Of Chromatin Structure At The Frataxin Gene In Friedreich’S Ataxia, Eunah Kim

Dissertations & Theses (Open Access)

Friedreich’s ataxia (FRDA) is caused by the transcriptional silencing of the frataxin (FXN) gene. FRDA patients have expansion of GAA repeats in intron 1 of the FXN gene in both alleles. A number of studies demonstrated that specific histone deacetylase inhibitors (HDACi) affect either histone modifications at the FXN gene or FXN expression in FRDA cells, indicating that the hyperexpanded GAA repeat may facilitate heterochromatin formation. However, the correlation between chromatin structure and transcription at the FXN gene is currently limited due to a lack of more detailed analysis. Therefore, I analyzed the effects of the hyperexpanded GAA …