Diet-induced obesity is characterized by macrophage (MF) infiltration and low-grade chronic inflammation in white adipose tissue (WAT) leading to insulin resistance. WAT MF are highly heterogeneous in their origin, patterns of gene expression and activities: unlike infiltrating monocyte-derived MF that promote inflammation and metabolic dysfunction, tissue-resident WAT MF originally described as ‘M2’ are phenotypically anti-inflammatory and counteract obesity and insulin resistance. Despite the critical role of the balance between these MF populations in metabolic homeostasis, the molecular mechanisms and key players that establish the resident MF transcription program are poorly understood. We recently reported that glucocorticoid receptor (GR)-interacting protein (GRIP)1 - a nuclear receptor coactivator - cooperates with GR to repress transcription of inflammatory genes. Here, using mice conditionally lacking GRIP1 in MF (cKO), we show that GRIP1 promotes MF polarization in response to IL4 (M2(IL4)) via a nuclear receptor-independent pathway by serving as a coactivator for Kruppel-like factor (KLF)4 – a critical driver of tissue MF differentiation. Interestingly, in vivo, GRIP1 cKO mice challenged with high-fat diet develop massive MF infiltration and chronic inflammation in WAT and liver, fatty livers, hyperglycemia, hyperinsulinemia and glucose intolerance consistent with metabolic syndrome phenotype. Together, our findings identify GRIP1 as a critical regulator of immunometabolism, which relies on distinct transcriptional mechanisms to coordinate the balance between MF populations in vivo thereby protecting mice from obesity-induced metabolic disease. Overall design: 1. Examination of IL4 induced transcriptome in in vitro differentiated primary bone marrow-derived macrophages. 2. Examination of macrophage transcriptome in macrophages isolated from the white adipose tissue of the WT and GRIP1(cKO) conditional KO animals
The transcriptional coregulator GRIP1 controls macrophage polarization and metabolic homeostasis.
Sex, Age, Specimen part, Subject
View SamplesGermline mutations of the SMARCB1 gene predispose to two distinct tumor syndromes: rhabdoid tumor predisposition syndrome, with malignant pediatric tumors mostly developing in brain and kidney, and familial schwannomatosis, with adulthood benign tumors involving cranial and peripheral nerves. The mechanisms by which SMARCB1 germline mutations predispose to rhabdoid tumors versus schwannomas are still unknown. Here, to understand the origin of these two types of SMARCB1-associated tumors, we generated different tissue- and developmental stage-specific conditional knockout mice carrying Smarcb1 and/or Nf2 deletion. Smarcb1 loss in early neural crest was necessary to initiate tumorigenesis in the cranial nerves and meninges with typical histological features and molecular profiles of human rhabdoid tumors. By inducing Smarcb1 loss at later developmental stage in the Schwann cell lineage, in addition to biallelic Nf2 gene inactivation, we generated the first mouse model developing schwannomas with the same underlying gene mutations found in schwannomatosis patients. Overall design: RNA-sequencing of 12 Smarcb1-deficient mouse cranial nerves and meninges tumors
Timing of Smarcb1 and Nf2 inactivation determines schwannoma versus rhabdoid tumor development.
Specimen part, Subject
View SamplesDespite the well-established role of the frontal and posterior peri-sylvian cortices in many facets of human-cognitive specializations, including language, little is known about the developmental patterning of these regions in human brain. We performed a genome-wide analysis of human cerebral patterning during mid-gestation, a critical epoch in cortical regionalization. A total of 345 genes were identified as differentially expressed (DE) between superior temporal gyrus (STG) and the remaining cerebral cortex (CTX). GO categories representing transcription factors were enriched in STG, while cell-adhesion and extracellular matrix molecules, were enriched in the other cortical regions. Q-PCR or in situ hybridization were performed to validate differential expression in a subset of 32 genes, most of which were confirmed. LIM domain binding 1 (LDB1), which we show to be enriched in the STG, is a recently identified interactor of LIM domain only 4 (LMO4), a gene known to be involved in the asymmetric pattering of the peri-sylvian region in the developing human brain. Protocadherin 17 (PCDH17), a neuronal cell adhesion molecule, was highly enriched in focal regions of the human prefrontal cortex. Contactin Associated Protein-Like 2 (CNTNAP2), in which mutations are known to cause autism, epilepsy and language delay, showed a remarkable pattern of anterior enriched expression in cortical regions important for human higher cognition. Importantly, a similar pattern was not observed in the mouse or rat. These data highlight the importance of expression analysis of human brain and the utility of cross-species comparisons of gene expression. Genes identified here provide a foundation for understanding molecular aspects of human-cognitive specializations and disorders that disrupt them.
Genome-wide analyses of human perisylvian cerebral cortical patterning.
Sex, Age
View SamplesHuman myelopoiesis is an exciting biological model for cellular differentiation since it represents a plastic process where pluripotent stem cells gradually limit their differentiation potential, generating different precursor cells which finally evolve into distinct terminally differentiated cells. This study aimed at investigating the genomic expression during myeloid differentiation through a computational approach that integrates gene expression profiles with functional information and genome organization. The genomic distribution of myelopoiesis genes was investigated integrating transcriptional and functional characteristics of genes. The analysis of genomic expression during human myelopoiesis using an integrative computational approach allowed discovering important relationships between genomic position, biological function and expression patterns and highlighting chromatin domains, including genes with coordinated expression and lineage-specific functions.
Motif discovery in promoters of genes co-localized and co-expressed during myeloid cells differentiation.
No sample metadata fields
View SamplesHuman myelopoiesis is an exciting biological model for cellular differentiation since it represents a plastic process where pluripotent stem cells gradually limit their differentiation potential, generating different precursor cells which finally evolve into distinct terminally differentiated cells. This study aimed at investigating the genomic expression during myeloid differentiation through a computational approach that integrates gene expression profiles with functional information and genome organization. The genomic distribution of myelopoiesis genes was investigated integrating transcriptional and functional characteristics of genes. The analysis of genomic expression during human myelopoiesis using an integrative computational approach allowed discovering important relationships between genomic position, biological function and expression patterns and highlighting chromatin domains, including genes with coordinated expression and lineage-specific functions.
Motif discovery in promoters of genes co-localized and co-expressed during myeloid cells differentiation.
No sample metadata fields
View SamplesRegional identity of several kind of human neural stem cells were assessed by RNA-Seq Overall design: We compared whole transcriptome of human fetal spinal cord, fetal brain, fetal spinal cord derived NSCs, H9-derived NSCs, H9-derived spinal cord NSCs, and UCSF4-derived spinal cord NSCs
Generation and post-injury integration of human spinal cord neural stem cells.
Specimen part, Subject
View SamplesBackground: Friedreich ataxia, an autosomal recessive neurodegenerative and cardiac disease, is caused by abnormally low levels of frataxin, an essential mitochondrial protein. All Friedreich ataxia patients carry a GAA/TTC repeat expansion in the first intron of the frataxin gene, either in the homozygous state or in compound heterozygosity with other loss-of-function mutations. The GAA expansion inhibits frataxin expression through a heterochromatin-mediated repression mechanism. Histone modifications that are characteristic of silenced genes in heterochromatic regions occur at expanded alleles in cells from Friedreich ataxia patients, including increased trimethylation of histone H3 at lysine 9 and hypoacetylation of histones H3 and H4.
HDAC inhibitors correct frataxin deficiency in a Friedreich ataxia mouse model.
No sample metadata fields
View SamplesAnalysis of gene expression by astrocytes or non-astrocyte cells in spinal cord injury (SCI) lesions may lead to the identification of molecules that impact on axon regrowth. We conducted genome-wide RNA sequencing of (i) immunoprecipitated astrocyte-specific ribosome-associated RNA (ramRNA) from WT or STAT3-CKO astrocytes, and (ii) the non-precipitated (flow-through) RNA deriving from non-astrocyte cells in the same tissue samples 14 days following SCI. DOI: 10.1038/nature17623 Overall design: Young adult female mGFAP-Cre-RiboTag or mGFAP-Cre-RiboTag-STAT3-LoxP mice underwent severe crush SCI at thoracic level 10. 14 days following SCI, the central 3mm of the SCI lesion was extracted, homogenized and (i) astrocyte-specific ribosome-associated RNA (ramRNA) precipitated via a hemagglutinin (HA) tag targeted to either WT (n=4) or STAT3-CKO (n=3) astrocytes, and (ii) the non-precipitated (flow-through) RNA deriving from non-astrocyte cells in the same tissue samples. Sex and age-matched mGFAP-Cre-RiboTag mice served as uninjured controls (n=4).
Astrocyte scar formation aids central nervous system axon regeneration.
Specimen part, Subject
View SamplesCounter to the long-held belief that DNA methylation of terminally differentiated cells is permanent and essentially immutable, post-mitotic neurons exhibit extensive DNA demethylation. The causal role of active DNA demethylation in neurons, however, is not known. Tet family proteins oxidize 5-methylcytosine to initiate active DNA demethylation through the base-excision repair pathway. Here, we show that synaptic activity bi-directionally regulates neuronal Tet3 expression. Functionally, knockdown of Tet or inhibition of base-excision repair in hippocampal neurons elevates excitatory glutamatergic synaptic transmission, whereas overexpressing Tet3 or Tet1 catalytic domain decreases it. Furthermore, dysregulation of Tet3 signalling prevents homeostatic synaptic plasticity. Mechanistically, Tet3 dictates neuronal surface GluR1 levels. RNA-seq analyses further revealed a pivotal role of Tet3 in regulating gene expression in response to global synaptic activity changes. Thus, Tet3 serves as a synaptic activity sensor to epigenetically regulate basic properties and meta-plasticity of neurons via active DNA demethylation. Overall design: Bicuculin, Tetradotoxin, shTet3
Tet3 regulates synaptic transmission and homeostatic plasticity via DNA oxidation and repair.
No sample metadata fields
View SamplesDuring neonatal development, skeletal muscle grows dramatically by myonuclei accretion to existing fibers and hypertophic growth of fibers with protein synthesis.
An NF-κB--EphrinA5-Dependent Communication between NG2(+) Interstitial Cells and Myoblasts Promotes Muscle Growth in Neonates.
Specimen part
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