Project description:Tet2 regulates gene expression by oxidizing 5-methylcytosine to 5-hydroxymethylcytosine. Profiling the genomic locations of 5-hydroxymethylcytosine after Tet2 manipulation can inform us of the targets of Tet2 regulation. We profiled hydroxymethylcytosine in Tet2 ovexpressing neurons to determine the targets of Tet2 in neurons.
Project description:Tet2 regulates gene expression by oxidizing 5-methylcytosine to 5-hydroxymethylcytosine. Profiling the genomic locations of 5-hydroxymethylcytosine after Tet2 manipulation can inform us of the targets of Tet2 regulation. We profiled hydroxymethylcytosine in Tet2 knockout neurons to determine the targets of Tet2 in neurons.
Project description:DNA methylation has emerged as a critical modulator of neuronal plasticity and cognitive function. Notwithstanding, the role of enzymes that demethylate DNA remain to be fully explored. Here, we report that loss of ten-eleven translocation methylcytosine dioxygenase 2 (Tet2), which catalyzes oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), in adult neurons enhances cognitive function. In the adult mouse hippocampus, we detected an enrichment of Tet2 in neurons. Viral-mediated neuronal overexpression and RNA interference of Tet2 altered dendritic complexity and synaptic-plasticity-related gene expression in vitro. Overexpression of neuronal Tet2 in adult hippocampus, and loss of Tet2 in adult glutamatergic neurons, resulted in differential hydroxymethylation associated with genes involved in synaptic transmission. Functionally, overexpression of neuronal Tet2 impaired hippocampal-dependent memory, while loss of neuronal Tet2 enhanced memory. Ultimately, these data identify neuronal Tet2 as a molecular target to boost cognitive function.
Project description:Gene expression profiles of Ngn3-overexpressing cultured hippocampal neurons was compared to the profile of the corresponding control populations. (neurons expressing GFP). Neurogenin3, a proneural transcription factor controlled by Notch receptor, is involved in hippocampal neuron differentiation and synapses, but little is known about the molecular bases of Ngn3 activity in neurons. Microarray analysis indicated that overexpression of Ngn3 upregulated a number of genes related with cytoskeleton dynamics. One of then was Fmn1 whose protein is associated with actin and microtubule cytoskeleton. Overexpression of the isoform Fmn1-Ib in cultured hippocampal neurons induced an increase in the number of primary dendrites and in the number of glutamatergic synaptic inputs without affecting GABAergic synapses resulting in a modification in the balance between excitation and inhibition. The same changes were provoked by overexpression of Ngn3. In addition downregulation of Fmn1 by the use of Fmn1-siRNAs impaired such morphological and synaptic changes induced by Ngn3 overexpression in neurons. These results reveal a previously unknown involvement of Formin1 in dendritic and synaptic plasticity as a key protein in the Nng3 signaling pathway that contributes to understanding of molecular mechanisms of the neuronal differentiation. Cultured hippocampal neurons were transduced using Sindbis virus bearing myc-tagged Ngn3 or GFP as control. Cells were lysed and total RNA was extracted.Gene expression profiles were obtained for each sample and compared
Project description:Chromatin methylation has emerged as a critical modulator of neuronal plasticity and cognitive function. Notwithstanding, the role of enzymes that demethylate DNA remain to be fully explored. Here we report that loss of ten eleven translocation methylcytosine dioxygenase 2 (Tet2), which catalyzes oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), in adult neurons enhances cognitive function. In the adult mouse hippocampus, we detected an enrichment of Tet2 in neurons. Abrogation of neuronal Tet2 in vitro altered synaptic-plasticity related gene expression. We observed that loss of Tet2 in mature glutamatergic neurons in adult mice resulted in differential hydroxymethylation on genes involved in synaptic transmission in the hippocampus. Correspondingly, RNA sequencing identified changes in both long-term potentiation pathways and immune-related genes linked to synaptic plasticity. Functionally, loss of neuronal Tet2 improved performance on hippocampal-dependent spatial and associative memory tasks. Ultimately, this work identifies neuronal Tet2 as a molecular target to enhance cognitive function.
Project description:Gene expression profiles of Ngn3-overexpressing cultured hippocampal neurons was compared to the profile of the corresponding control populations. (neurons expressing GFP). Neurogenin3, a proneural transcription factor controlled by Notch receptor, is involved in hippocampal neuron differentiation and synapses, but little is known about the molecular bases of Ngn3 activity in neurons. Microarray analysis indicated that overexpression of Ngn3 upregulated a number of genes related with cytoskeleton dynamics. One of then was Fmn1 whose protein is associated with actin and microtubule cytoskeleton. Overexpression of the isoform Fmn1-Ib in cultured hippocampal neurons induced an increase in the number of primary dendrites and in the number of glutamatergic synaptic inputs without affecting GABAergic synapses resulting in a modification in the balance between excitation and inhibition. The same changes were provoked by overexpression of Ngn3. In addition downregulation of Fmn1 by the use of Fmn1-siRNAs impaired such morphological and synaptic changes induced by Ngn3 overexpression in neurons. These results reveal a previously unknown involvement of Formin1 in dendritic and synaptic plasticity as a key protein in the Nng3 signaling pathway that contributes to understanding of molecular mechanisms of the neuronal differentiation.
Project description:We induced over-expression and under-expression of Camk2b in cultured rat hippocampal neurons through transfection with lentivirus plasmids. Then isobaric tag for relative and absolute quantitation (iTRAQ)-based quantitative proteomics followed by bioinformatics analyses were carried out to explore the impacts of Camk2b dysexpression on the proteome of the neurons.
Project description:T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive proliferation of T-lymphocytes usually associated with oncogenic activation of NOTCH1 signaling. Using a bone marrow transplantation approach, we have modeled murine CD4+ CD8+ T-ALL by overexpressing DNMT3A R882H in Tet2-/- multipotent progenitors. T-ALL derived from NOTCH1 L1601PdelP Tet2-/-, NOTCH1 L1601PdelP Tet2+/+ or TCL1A progenitors were used for comparison, as well as normal Tet2+/+ and Tet2-/- CD4+ CD8+ double positive (DP) thymocytes.
Project description:Tet2 functions in the CA1 as a negative regulator of long-term memory, and its haploinsufficiency in glutamatergic neurons or knockdown across the CA1 in mice is sufficient to enhance the fidelity of hippocampal-dependent spatial and associative memory.