Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Loss of neuronal 3D chromatin organization causes transcriptional and behavioral deficits related to serotonergic dysfunction

ABSTRACT: The interior of the eukaryotic cell nucleus is a highly organized 3D structure. In mature hippocampal and cortical pyramidal neurons, transcriptionally silent DNA is typically compacted in a few clusters referred to as chromocenters that are strongly stained with DNA intercalating agents like DAPI and whose function is still uncertain. We found that this 3D structure was severely disrupted by the incorporation of the chimeric histone H2BGFP into neuronal chromatin. Experiments in inducible and forebrain restricted bitransgenic mice demonstrated that the expression of this histone alters the higher-order organization of neuronal heterochromatin and causes a complex behavioral phenotype that includes hyperactivity, and social interaction, prepulse inhibition and cognitive defects. This phenotype was associated with highly specific transcriptional deficits that affected several serotonin receptor genes located at the edge of gene desert regions. Pharmacological and electrophysiological experiments indicate that this epigenetically-induced hyposerotonergic state may underlie the behavioral defects. Our results suggest a new role for perinuclear heterochromatin and chromocenter organization in the epigenetic regulation of neuronal gene expression and mental illness. We used microarrays to detect differential gene expression in transgenic mice expressing histone H2BGFP in the forebrain. We obtained triplicate samples (biological replicates) of either genotype (wild-type and H2BGFP mice). Each sample contained pooled total RNA from the hippocampi of 2 three-month old genotype-matched mice.

ORGANISM(S): Mus musculus

SUBMITTER: jose lopez

PROVIDER: E-GEOD-48437 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:G protein coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active Gs-coupled GPCR, under the control of the 2.3 kb-Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone which were accompanied by an increase in OB lineage cells, especially immature OBs, indicated by an expansion of cells expressing Osterix and Runx2 in the whole femur. In this study, we further evaluated how Gs signaling in OBs affects intramembranous bone formation by examining calvariae of one-and nine-week-old Col1(2.3)/Rs1 mice. Rs1 calvariae displayed a dramatic increase in total volume and trabecular bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space in Rs1 expressing mice while Osteocalcin was expressed predominantly in cells along bone surfaces. These findings resembled that previously seen in Rs1 femoral bones, suggesting the role of paracrine mediators secreted from OBs driven by 2.3 kb-Col I promoter could influence early OB commitment, differentiation, and/or proliferation. However, it is still unclear how G protein signaling in mature OBs leads to the observed alterations in bone mass. In this study, we investigated the cellular basis of the skeletal changes by assessing the effect of Rs1 expression in vivo on the transcriptome of mature OBs. We identified the complete set of Gs-GPCRs and other GPCRs that are expressed on OBs which may contribute to the observed skeletal phenotype. Candidate paracrine mediators of the effect of Gs signaling in OBs were determined. Genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. Our results identify novel candidate mediators of the anabolic response to the skeleton to Gs signaling in mature OBs. We utilized a microarray approach to examine Rs1-induced alterations in the OB transcriptome. The approach used to identify an approximate snapshot of the OB transcriptome at the time of sacrifice by isolating the OB population that expresses Rs1 by GFP labeling, without the use of cell culture. We compared gene expression between control OBs and OBs-expressing Rs1 in triplicates.

Project description:Increasing evidence suggests that microRNAs may play important roles in regulating self-renewal and differentiation in mammalian stem cells (SCs). Here, we explore this issue in skin. We first characterize microRNA expression profiles of skin SCs versus their committed proliferative progenies and identify a microRNA subset associating with “stemness”. Of these, miR-125b is dramatically downregulated in early SC-progeny. We engineer an inducible mice system and show that when miR-125b is sustained in SC-progenies, tissue balance is reversibly skewed towards stemness at the expense of epidermal, oil-gland and HF differentiation. Using gain-and-loss of function in vitro, we further implicate miR-125b as a repressor of SC differentiation. In vivo, transcripts repressed upon miR-125b induction are enriched >700% for predicted miR-125b targets normally downregulated upon SC-lineage commitment. We verify some of these miR-125b targets, and show that Blimp1 and VDR in particular can account for many tissue imbalances we see when miR-125b is deregulated. We used microarrays to compare the global miRNA expression profile of P4 stage hair follicle ORS cells from DTG (K14-rtTA,TRE-miR-125b) and control littermates. Hair follicle cells were isolated from P4 Backskin (Dox since P3 for 24hrs) of DTG (K14-rtTA/TRE-miR-125b/K14-H2BGFP), TRE (TRE-miR-125b/K14-H2BGFP), KrtA (K14-rtTA/K14-H2BGFP) as following: interfollicular epidermis sheet was pealed from hair follicle & dermis after dispase treatment.The hair follicle & dermis were first digested by collagenase (Sigma). Intact hair follicles were separated from dermal cells by low speed spinning (20g). The hair follicles were then digested by Trypsin and filtered by 40 µm cell strainers. The isolated hair follicle cells were FACS sorted. During FACS, cells were first gated against CD34 (endothelial cells), CD45 (immune cells), CD114 (melanocytes) and DAPI (dead cells). ORS cells were sorted from the remaining cells as α6HiGFPHi.

Dataset Information

Loss of neuronal 3D chromatin organization causes transcriptional and behavioral deficits related to serotonergic dysfunction

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure