Project description:Using the highly sensitive miRNA array, we screened 40 microRNAs abundant in the olfactory bulb and we explored the functions of these miRNAs in the olfactory bulb by Gene Ontology and Kyoto Encyclopedia of Genes annotation. The enrichment results indicated that these miRNAs mainly participated in the axon guidance process. Furthermore, the quantitative real-time polymerase chain reaction, immunohistochemistry, and dual luciferase reporter assay results showed that miR-30c is a specific regulator of semaphorin-3A, which will give new insights in disclosing the mechanism of functional maintenance and sexual-specific differentiation of the olfactory bulb. In this study, three samples from steady-state mice were used to acquire the miRNA expression profiling and the function of the abudant miRNAs in the olfactory bulb were analyzed by bioinformatic methods.Finally, miR-30c was experimentally validated to be a regulator of semaphorin-3A, an important axon guidance cue in the nervous system.
Project description:Using the highly sensitive miRNA array, we screened 40 microRNAs abundant in the olfactory bulb and we explored the functions of these miRNAs in the olfactory bulb by Gene Ontology and Kyoto Encyclopedia of Genes annotation. The enrichment results indicated that these miRNAs mainly participated in the axon guidance process. Furthermore, the quantitative real-time polymerase chain reaction, immunohistochemistry, and dual luciferase reporter assay results showed that miR-30c is a specific regulator of semaphorin-3A, which will give new insights in disclosing the mechanism of functional maintenance and sexual-specific differentiation of the olfactory bulb.
Project description:Using the highly sensitive miRNA array, we screened 40 microRNAs abundant in the olfactory bulb and we explored the functions of these miRNAs in the olfactory bulb by Gene Ontology and Kyoto Encyclopedia of Genes annotation. The enrichment results indicated that these miRNAs mainly participated in the axon guidance process. Furthermore, the quantitative real-time polymerase chain reaction, immunohistochemistry and dual luciferase reporter assay results showed that miR-30c is a specific regulator of semaphorin-3A, which will give new insights in disclosing the mechanism of functional maintenance and sexual-specific differentiation of the olfactory bulb.
Project description:We have discovered subsets of axon guidance molecules and transcription factors that are enriched in specific subsets of olfactory sensory neurons. We have demonstrated guidance activity for three of the candidate axon guidance genes we identified, suggesting that this approach is an efficient method for characterizing guidance systems relevant to olfactory axon targeting.
Project description:The progeny of neural stem cells in the subventricular zone (SVZ) of the adult mammalian brain consists in polysialylated NCAM-expressing immature neurons (PSA(+) cells), which migrate to the olfactory bulb (OB) to differentiate into GABAergic interneurons. We purified murine PSA(+) cells directly from the adult brain by FACS and analyzed their gene expression profile by SAGE. Comparative analyses led to the identification of precursor-enriched genes, including Survivin, Sox-4, Meis2, Dishevelled-2, C3aR1 and Riken 3110003A17, and many so far uncharacterized transcripts. Cluster analysis showed that groups of genes involved in axon guidance and gene clusters implicated in chemotaxis are strongly upregulated, indicating a role of both cues in the control of cell migration in the adult brain. Furthermore, genes involved in apoptosis and cell proliferation are co-expressed, suggesting that the amount of precursors that is present in the adult brain is a result of an equilibrium of these processes. Keywords: neuronal precursors, adult SVZ, mouse, gene expression analysis
Project description:The goal of this study is to profile NFIA DNA-binding properties in the adult mouse brain. We performed chromatin immunoprecipitation of NFIA in the hippocampus and olfactory bulb of wildtype mice, and samples were subjected to sequencing. We find that NFIA preferentially binds DNA in the hippocampus but not in the olfactory bulb as evidenced by the distinct lack of NFIA binding peaks in the olfactory bulb. Mass spectrometry results suggested that NFIA has a significantly higher binding affinity for NFIB in the olfactory bulb, potentially blocking NFIA’s ability to bind DNA. Virally induced siRNAs against NFIB or scramble were injected into the olfactory bulb of adult wildtype mice to knock down NFIB. We performed chromatin immunoprecipitation of NFIA in the olfactory bulb injected with siRNA-NFIB or siRNA-scramble. Subsequent sequencing revealed an increase of NFIA binding in the olfactory bulb upon the depletion of NFIB as compared to the siRNA-scramble and wildtype controls.
Project description:The progeny of neural stem cells in the subventricular zone (SVZ) of the adult mammalian brain consists in polysialylated NCAM-expressing immature neurons (PSA(+) cells), which migrate to the olfactory bulb (OB) to differentiate into GABAergic interneurons. We purified murine PSA(+) cells directly from the adult brain by FACS and analyzed their gene expression profile by SAGE. Comparative analyses led to the identification of precursor-enriched genes, including Survivin, Sox-4, Meis2, Dishevelled-2, C3aR1 and Riken 3110003A17, and many so far uncharacterized transcripts. Cluster analysis showed that groups of genes involved in axon guidance and gene clusters implicated in chemotaxis are strongly upregulated, indicating a role of both cues in the control of cell migration in the adult brain. Furthermore, genes involved in apoptosis and cell proliferation are co-expressed, suggesting that the amount of precursors that is present in the adult brain is a result of an equilibrium of these processes. Keywords: neuronal precursors, adult SVZ, mouse, gene expression analysis Please see Pennartz et al., Mol Cell Neurosci. 2004 Apr;25(4):692-706 and PhD thesis "Gene expression analysis of neuronal precursors from adult mouse brain and differential screen for neural stem cell markers" http://deposit.ddb.de/cgi-bin/dokserv?idn=973392754
Project description:Olfactory sensory neurons (OSNs) transform the stochastic choice of one out of >1000 olfactory receptor (OR) genes into precise and stereotyped axon targeting of OR-specific glomeruli in the olfactory bulb. Here, we show that the PERK arm of the unfolded protein response (UPR) regulates both the glomerular coalescence of like axons, and the specificity of their projections. Subtle differences in OR protein sequences lead to distinct patterns of endoplasmic reticulum (ER) stress during OSN development, converting OR identity into distinct gene expression signatures. We identify the transcription factor Ddit3 as a key effector of PERK signaling that maps OR-dependent ER signaling patterns to the transcriptional regulation of axon guidance and cell adhesion genes, instructing targeting precision. Our results extend the known functions of the UPR from a quality control pathway that protects cells from misfolded proteins, to a sensor of cellular identity that interprets physiological states to direct axon wiring.