Transcription factors expressed in olfactory bulb local progenitor cells revealed by genome-wide transcriptome profiling
Ontology highlight
ABSTRACT: We used transcriptional profiling to monitor gene expression of whole olfactory bulbs at daily intervals from embryonic day 11 through birth, generating a compendium of gene expression encompassing the major developmental events of this tissue.
Project description:We used transcriptional profiling to monitor gene expression of whole olfactory bulbs at daily intervals from embryonic day 11 through birth, generating a compendium of gene expression encompassing the major developmental events of this tissue. OBs from CD1 mice (Charles River Laboratories, Wilmington, MA), were isolated from embryos daily between E11 and postnatal day zero (P0), for a total of nine time points. RNA was purified with TRIzol reagent (Invitrogen, Carlsbad, CA), subjected to two rounds of amplification, labeled, and hybridized to Affymetrix Mouse Genome 430.2 GeneChip microarrays (Affymetrix Inc., Santa Clara, CA, USA) using Affymetrix reagents and protocols (http://www.affymetrix.com). One microarray for each time point using RNA from the OBs of one individual embryo.
Project description:We report genome-wide gene expression changes in olfactory bulb cells, in the context of low, wild-type or high levels of local CRH signaling by local interneurons onto adult-born CRHR1+ granule neurons. To test the gene expression changes associated with altered local CRH signaling, we utilize the following animal models: CRHR1-/- mice whose bulbs were infected with a control AAV-flex-EGFP virus = low local CRH signaling, CRHR1-Cre mice whose bulbs were infected with AAV-flex-EGFP = pseudo-wild-type local CRH signaling, and CRHR1-Cre mice whose bulbs were infected with AAV-flex-(CA)CRHR1, which is a constitutively active variant of CRHR1 = high local CRH signaling. We find that, in response to changes in local CRH signaling in the bulb, the largest ontological category of transcription changes in the bulb that occurs reciprocally between low and high levels of CRH signaling are gene regulatory factors. To test the contributions of one of these factors, POU6f1, we perform loss- and gain-of-function analysis. We show that CRHR1 activation results in transcriptional activation of POU6f1 and that POU6f1 in turn influences synaptogenesis and dendritic patterning of adult-born neurons and olfactory circuit behavior.
Project description:Purpose: To asses changes in gene expression profiles from the P11 no cre littermate control olfactory bulbs and conditional double knockout olfactory bulbs of Dlx5/6-CIE; Sp8 Flox/Flox; Sp9 Flox/Flox (Sp8/Sp9-DCKO) mice. Methods: Total RNA was isolated and sequenced from the olfactory bulbs of the P11 no cre littermate controls or Sp8/Sp9-DCKO mice in duplicate using an illumina high-seq 2500. Raw data was analyzed using TopHat. Genes were considered changed which performed fold-change>=2 and FDR<=0.05. Changed genes were then filtered to reveal the downstream targets of Sp8 and Sp9. Results: 32 genes were significantly increased and 144 genes were significantly decreased in expression level due to the loss of Sp9 and Sp8 expression.
Project description:Purpose: To asses changes in gene expression profiles from the P30 wild type littermate control olfactory bulbs and conditional double knockout olfactory bulbs of hGFAP-Cre; Sp8 Flox/Flox; Sp9 Flox/Flox mice. Methods: Total RNA was isolated and sequenced from the olfactory bulbs of the P30 wild type littermate controls or hGFAP-Cre; Sp8 Flox/Flox; Sp9 Flox/Flox mice in tetrad using an illumina high-seq 2500. Raw data was analyzed using TopHat. Genes were considered changed which performed fold-change>=2 and FDR<=0.05. Changed genes were then filtered to reveal the downstream targets of Sp8 and Sp9. Results: 31 genes were significantly increased and 74 genes were significantly decreased in expression level due to the loss of Sp9 and Sp8 expression.
Project description:Tuberous Sclerosis Complex (TSC) is a neurodevelopmental disorder caused by mutations that inactivate TSC1 or TSC2. Hamartin and tuberin are encoded by TSC1 and TSC2 which form a GTPase activating protein heteromer that inhibits the Rheb GTPase from activating a growth promoting protein kinase called mammalian target of rapamycin (mTOR). Growths and lesions occur in the ventricular-subventricular zone (V-SVZ), cortex, olfactory tract, and olfactory bulbs (OB) in TSC. Here, nestin-CRE-ERT2 mice were injected with tamoxifen at postnatal days 2 and 3 and brains harvested at postnatal day 60. OBs were subsequently subjected to RNA sequencing.
Project description:Metabolic imbalance contributes to cognitive impairment, anxiety, depressive behavior, and impaired olfactory perception. As the synaptic signal from the olfactory bulb is directly transmitted to memory consolidation-related brain regions, recent studies have focused on the study of olfactory dysfunction in patients with obesity and diabetes accompanied by cognitive dysfunction. In this study, we investigated the transcriptomic change of olfactory bulb in high-fat diet-fed mice compared to that of normal diet-fed mice. We sampled olfactory bulbs from high fat diet mice, performed RNA sequencing, and measured protein and mRNA levels in olfactory bulb tissue. Also, we tested cytokine secretion in blood plasma of high fat diet mice. We found differences in the expression of protein-coding mRNAs and non-coding RNAs involved in insulin, lipid metabolism, neurogenesis, serotonin, dopamine, and gamma-aminobutyric acid-related signaling in the olfactory bulb of high-fat diet-fed mice compared to control mice. Our analyses suggest diverse targets for the treatment of olfactory dysfunction related to various neuropathologies in patients with metabolic syndrome.
Project description:Anosmia, the loss of smell, is a common and often the sole symptom of COVID-19. The onset of the sequence of pathobiological events leading to olfactory dysfunction remains obscure. Here, we have developed a postmortem bedside surgical procedure to harvest endoscopically samples of respiratory and olfactory mucosae and whole olfactory bulbs. Our cohort of 85 cases included COVID-19 patients who died a few days after infection with SARS-CoV-2, enabling us to catch the virus while it was still replicating. We found that sustentacular cells are the major target cell type in the olfactory mucosa. We failed to find evidence for infection of olfactory sensory neurons, and the parenchyma of the olfactory bulb is spared as well. Thus, SARS-CoV-2 does not appear to be a neurotropic virus. We postulate that transient insufficient support from sustentacular cells triggers transient olfactory dysfunction in COVID-19. Olfactory sensory neurons would become affected without getting infected.
Project description:We performed deep-sequencing analysis of small RNA extracted from neuronal progenitors at different developmental stages. The RNA samples were extracted from microdissected tissues of dorsal or lateral sub-ventricular zone (SVZ) (to analyze the immature progenitor pools), of rostral migration stream (RMS) (to analyze the migrating neuroblasts) or of olfactory bulbs (OB) (to analyze both immature and mature neurons). These tissues were dissected from animals at variable ages: P1 and P6 for SVZ samples, P15 and P28 for RMS and OB samples. Expression profile of microRNA in time and space along post-natal neurogenesis
Project description:Olfactory ensheathing cells (OECs) are the only glial cells that support the olfactory sensory neurons which undergo adult neurogenesis and continually project their axons to glomeruli in the olfactory bulbs. We used single cell RNA sequencing to study the gene expression programs of OECs and to determine the diversity of purified OECs previously shown to promote spinal cord injury repair. Our analyses revealed five subtypes of OECs, each expressing unique marker genes and pathways indicative of progenitor, axonal regeneration, migration, or microglia-like functions. As expected, we found substantial overlap of OEC genes with those of Schwann cells, but also with astrocytes, oligodendrocytes and microglia. We experimentally confirmed the classic marker genes of the OEC subtypes and provide evidence that Reelin and Connective Tissue Growth Factors are secreted by multiple OEC subtypes. Our results support that adult OECs are a hybrid glia including some with progenitor characteristics and that they likely carry out diverse functions related to injury repair and axonal regeneration.