Cocaine-mediated repression of the histone methyltransferase (HMT) G9a has recently been implicated in transcriptional, morphological, and behavioral responses to chronic cocaine administration. Here, using a ribosomal affinity purification approach, we find that G9a repression by cocaine occurs in both Drd1 (striatonigral)- and Drd2 (striatopallidal)-expressing medium spiny neurons (MSNs). Conditional knockout and overexpression of G9a within these distinct cell types, however, reveals divergent behavioral phenotypes in response to repeated cocaine treatment. Our studies further indicate that such developmental deletion of G9a selectively in Drd2 neurons results in the unsilencing of transcriptional programs normally specific to striatonigral neurons, and the acquisition of Drd1-associated projection and electrophysiological properties. This partial striatopallidal to striatonigral switching phenotype in mice indicates a novel role for G9a in contributing to neuronal subtype identity, and suggests a critical function for cell-type specific histone methylation patterns in the regulation of behavioral responses to environmental stimuli.
G9a influences neuronal subtype specification in striatum.
Sex, Specimen part
View SamplesThroughout postnatal life in mammals, neural stem cells (NSCs) are located in the subventricular zone (SVZ) of the lateral ventricles. The greatest diversity of neuronal and glial lineages they generate occurs during early postnatal life in a region-specific manner. In order to evaluate potential heterogeneity in the NSC pool, we microdissected the dorsal and lateral SVZ at different postnatal ages and isolated NSCs and their immediate progeny based on their expression of Hes5-EGFP/Prominin1 and Ascl1-EGFP, respectively. Whole genome comparative transcriptome analysis revealed transcriptional regulators as major hallmarks that sustain postnatal SVZ regionalization. Manipulation of single genes encoding for locally enriched transcription factors influenced NSC specification indicating that the fate of regionalized postnatal SVZ NSCs can be readily modified . These findings reveal functional heterogeneity of NSCs in the postnatal SVZ and provide targets to recruit region-specific lineages in regenerative contexts.
Transcriptional Hallmarks of Heterogeneous Neural Stem Cell Niches of the Subventricular Zone.
Specimen part
View SamplesMicroRNAs have emerged as major genetic elements in the genesis and suppression of cancer. Here, multi-dimensional cancer genome analysis and validation has defined a novel Glioblastoma Multiforme (GBM) tumor suppressor pathway and mechanism of action centered on Quaking (QK), a member of the STAR family of RNA-binding proteins. Combined functional, biochemical and computational studies establish that p53 directly regulates QK gene expression, QK protein binds and stabilizes miR-20a of the cancer-relevant miR-17-92 cluster, and miR-20a in turn functions to regulate TGFR2 and the TGF signaling network. Linkage of these pathway components is supported by their genome and expression status across GBM specimens and by their gain- and loss-of-function interactions in in vitro and in vivo complementation studies. This p53-QK-miR-20a axis expands our understanding of the p53 tumor suppression network in cancer and reveals a novel tumor suppression mechanism involving regulation of specific cancer-relevant microRNAs.
STAR RNA-binding protein Quaking suppresses cancer via stabilization of specific miRNA.
Specimen part, Cell line
View SamplesIdentify potential QK-regulated mRNAs and linked pathways by comparing the transcriptional profiles of shGFP- and shQK-transduced Ink4a/Arf-/- Pten-/- primary mouse astrocytes
STAR RNA-binding protein Quaking suppresses cancer via stabilization of specific miRNA.
No sample metadata fields
View SamplesIdentify potential miR-20a regulated mRNAs and linked pathways in the setting of QK knockdown by comparing the transcriptional profiles of shQK-transduced primary mouse Ink4a/Arf-/- Pten-/- astrocytes together with miR-20a or a scrambled miRNA control (miR-NT)
STAR RNA-binding protein Quaking suppresses cancer via stabilization of specific miRNA.
No sample metadata fields
View SamplesTo elucidate the mechanism of BCL6-mediated pre-B cell survival signaling, we investigated the gene expression pattern in BCR-ABL1-transformed BCL6+/+ and BCL6-/- B cell precursors. Pharmacological inhibition of BCR-ABL1 was performed with the BCR-ABL1 kinase inhibitor STI571 (Imatinib).
BCL6 is critical for the development of a diverse primary B cell repertoire.
Sex, Age, Specimen part, Treatment
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