Project description:To gain a deeper insight into roles of Arid1a in mice hippocampus development, we performed ChIP-seq and RNA-seq to analyze the genome-wide changes of histone marks and transcriptome changes before and after Arid1a deletion in hippocampus of the E16.5 and P21 mouse using Cre-lox system.
Project description:Single-nuclei Assay for Transposase-Accessible Chromatin with sequencing (snATACseq) was applied to examine chromatin landscape changes and transcriptional regulator (TR) DNA motif accessibility in reactive astrocytes following traumatic spinal cord injury (SCI). Astrocyte nuclei were isolated from the spinal cord of wild type mice and mice with astrocyte-specific conditional gene deletion (cKO) of test-case TRs, SMARCA4 (Smarca4-astro-cKO) or STAT3 knockout (Stat3-astro-cKO). Comparison of differential chromatin accessibility revealed substantial remodeling during astrocyte reactivity, with more chromatin opening than closing. Marked alterations in access to SCI reactivity-associated TR motifs were also detected.
Project description:Single-nuclei Assay for Transposase-Accessible Chromatin with sequencing (snATACseq) was applied to examine chromatin landscape changes and transcriptional regulator (TR) DNA motif accessibility in reactive astrocytes following neuroinflammatory insult by systemic administration of lipopolysaccharide (LPS). Astrocyte nuclei were isolated from the spinal cord of wild type mice and mice with astrocyte-specific conditional gene deletion (cKO) of test-case TRs, SMARCA4 (Smarca4-astro-cKO) or STAT3 knockout (Stat3-astro-cKO). Comparison of differential chromatin accessibility revealed substantial remodeling during astrocyte reactivity, with more chromatin opening than closing. Marked alterations in access to LPS reactivity-associated TR motifs were also detected.
Project description:Prolonged seizures can disrupt stem cell behavior in the adult hippocampus, an important brain structure for spatial memory. Here, using a mouse model of pilocarpine-induced status epilepticus (SE), we characterized spatiotemporal expression of Lin28a mRNA and proteins after SE. Unlike Lin28a transcripts, induction of LIN28A protein after SE was detected mainly in the subgranular zone, where immunoreactivity was found in progenitors, neuroblasts, and immature and mature granule neurons. To investigate roles of LIN28A in epilepsy, we generated Nestin-Cre::Lin28aloxP/loxP (cKO) and Nestin-Cre::Lin28a+/+ (WT) mice to block LIN28A upregulation in all neuronal lineages after acute seizure. Adult-generated neuron- and hippocampus-associated cognitive impairments were absent in epileptic LIN28A cKO mice as evaluated by pattern separation and contextual fear conditioning tests, respectively, while sham-manipulated WT and cKO animals showed comparable memory function. Moreover, numbers of hilar PROX1-expressing ectopic granule cells (EGCs), together with PROX1/NEUN+ mature EGCs, were significantly reduced in epileptic cKO mice. Transcriptomic analysis and immunohistochemical validation at 3 d post-pilocarpine provided potential LIN28A downstream targets such as serotonin receptor 4. Collectively, our findings indicate that LIN28A is a novel target for regulation of newborn neuron-associated memory dysfunction in epilepsy by modulating seizure-induced aberrant neurogenesis.
Project description:We aimed at investigating the function of TIP60 in the in the mammalian hippocampus. For this, we used mice with a forebrain-specific deletion of Tip60 upon tamoxifen injection (Tip60 cKO). RNA-sequencing was applied to examine the transcriptome changes in the CA1 region upon Tip60 deletion. We observed massive transcriptional changes and identified a neurodegeneration-related signature at a time when there are no obvious morphological changes in Tip60 cKO mice. Later on these mice develop extensive neurodegeneration in hippocampal CA1.
Project description:CCCTC-binding factor (CTCF) is an 11 zinc finger DNA-binding domain protein that regulates gene expression by modifying 3D chromatin structure. Human mutations in CTCF cause intellectual disability and autistic features. Knocking out Ctcf in mouse embryonic neurons is lethal by neonatal age, but the effects of CTCF deficiency in postnatal neurons are less well studied. We knocked out Ctcf postnatally in glutamatergic forebrain neurons under the control of Camk2a-Cre. Ctcf loxP/loxP;Camk2a-Cre (Ctcf CKO) mice of both sexes were viable and exhibited profound deficits in spatial learning/memory, impaired motor coordination, and decreased sociability by 4 months of age. Ctcf CKO mice also had reduced dendritic spine density in the hippocampus and cerebral cortex. Microarray analysis of mRNA from Ctcf CKO mouse hippocampus identified increased transcription of inflammation-related genes linked to microglia. Separate microarray analysis of mRNA isolated specifically from Ctcf CKO mouse hippocampal neurons by ribosomal affinity purification identified upregulation of chemokine signaling genes, suggesting crosstalk between neurons and microglia in Ctcf CKO hippocampus. Finally, we found that microglia in Ctcf CKO mouse hippocampus had abnormal morphology by Sholl analysis and increased immunostaining for CD68, a marker of microglial activation. Our findings confirm that Ctcf KO in postnatal neurons causes a neurobehavioral phenotype in mice and provide novel evidence that CTCF depletion leads to overexpression of inflammation-related genes and microglial dysfunction.
Project description:CCCTC-binding factor (CTCF) is an 11 zinc finger DNA-binding domain protein that regulates gene expression by modifying 3D chromatin structure. Human mutations in CTCF cause intellectual disability and autistic features. Knocking out Ctcf in mouse embryonic neurons is lethal by neonatal age, but the effects of CTCF deficiency in postnatal neurons are less well studied. We knocked out Ctcf postnatally in glutamatergic forebrain neurons under the control of Camk2a-Cre. Ctcf loxP/loxP;Camk2a-Cre (Ctcf CKO) mice of both sexes were viable and exhibited profound deficits in spatial learning/memory, impaired motor coordination, and decreased sociability by 4 months of age. Ctcf CKO mice also had reduced dendritic spine density in the hippocampus and cerebral cortex. Microarray analysis of mRNA from Ctcf CKO mouse hippocampus identified increased transcription of inflammation-related genes linked to microglia. Separate microarray analysis of mRNA isolated specifically from Ctcf CKO mouse hippocampal neurons by ribosomal affinity purification identified upregulation of chemokine signaling genes, suggesting crosstalk between neurons and microglia in Ctcf CKO hippocampus. Finally, we found that microglia in Ctcf CKO mouse hippocampus had abnormal morphology by Sholl analysis and increased immunostaining for CD68, a marker of microglial activation. Our findings confirm that Ctcf KO in postnatal neurons causes a neurobehavioral phenotype in mice and provide novel evidence that CTCF depletion leads to overexpression of inflammation-related genes and microglial dysfunction.
Project description:INPP5D, which encodes the lipid phosphatase SHIP1, is one of the most common genes associated with the risk of Alzheimer’s disease and is enriched in microglia in the central nervous system. SHIP1 has been found to be highly expressed in plaque-associated microglia. However, how it regulates microglial function and influences brain physiology has been poorly investigated. Here we show that SHIP1 is not only enriched in microglia associated with amyloid beta plaques, but also in early stages of healthy brain development. By combining in vivo loss-of-function approaches and proteomics, we discovered that conditional knockout mice lacking microglial SHIP1 (cKO) display increased complement and synapse loss in the early postnatal brain. Additionally, SHIP1 KO microglia show reduced morphological complexity, altered transcriptional signatures, and abnormal synaptic pruning, which is dependent on the complement system. Single nucleus RNA-sequencing analysis of the entire hippocampus confirmed decreased interaction for synaptic structure-related pathways in both excitatory and inhibitory neurons. Importantly, cKO mice show cognitive defects in adulthood only when microglial SHIP1 is depleted at early postnatal days, but not when depleted at later stages. Finally, using CRISPR/Cas9 we generated human iPSC-derived microglia lacking SHIP1, and validated the increased engulfment of synaptic structures. Altogether, these findings suggest that SHIP1 is essential for proper microglia-mediated synapse remodeling through the complement system in the early postnatal brain. Disrupting this process has lasting behavioral effects and may provide a link to vulnerability to neurodegeneration.