Project description:Nurr1 (Nr4a2, nuclear receptor subfamily 4 group A member 2) is needed for the development of ventral midbrain dopaminergic neurons, and has been associated with Parkinson's disease. We used mice where the Nurr1 gene is ablated by tamoxifen treatment selectively in dopaminergic neurons. As a control, we used tamoxifen-treated mice where Nurr1 is not ablated. By laser microdissection of neurons selected by their TH1 (Th1l, TH1-like homolog) gene expression, we selected dopaminergic neurons for RNA extraction and high-throughput mRNA sequencing, in order to identify genes regulated by Nurr1. We found the main functional category of Nurr1-regulated genes are the nuclear-encoded mitochondrial genes. Dopaminergic neurons with or without Nurr1 knocked out. TH-positive neurons were laser capture microdissected from cryostat coronal sections of the midbrain.
Project description:Nurr1 (Nr4a2, nuclear receptor subfamily 4 group A member 2) is needed for the development of ventral midbrain dopaminergic neurons, and has been associated with Parkinson's disease. We used mice where the Nurr1 gene is ablated by tamoxifen treatment selectively in dopaminergic neurons. As a control, we used tamoxifen-treated mice where Nurr1 is not ablated. By laser microdissection of neurons selected by their TH1 (Th1l, TH1-like homolog) gene expression, we selected dopaminergic neurons for RNA extraction and high-throughput mRNA sequencing, in order to identify genes regulated by Nurr1. We found the main functional category of Nurr1-regulated genes are the nuclear-encoded mitochondrial genes.
Project description:The transcription factor nurr1 plays a pivotal role in the development and maintenance of neurotransmitter phenotype in midbrain dopamine neurons. Conversely, decreased nurr1 expression is associated with a number of dopamine-related CNS disorders, including Parkinson’s disease and drug addiction. In order to better understand the nature of nurr1-responsive genes and their potential roles in dopamine neuron differentiation and survival, we used a neural cellular background in which to generate a number of stable clonal lines with graded nurr1 gene expression that approximated that seen in DA cell-rich human substantia nigra. Gene expression profiling data from these nurr1-expressing clonal lines were validated by quantitative RT-PCR and subjected to bioinformatic analyses. The present study identified a large number of nurr1-responsive genes and demonstrated the potential importance of concentration-dependent nurr1 effects in the differential regulation of distinct nurr1 target genes and biological pathways. These data support the promise of nurr1-based CNS therapeutics for the neuroprotection and/or functional restoration of DA neurons. Total RNA obtained from nurr1-overexpressing SKNAS neuroblastoma clonal cell lines (SKNAS_E & SKNAS_G) compared to empty vector transfected control (SKNAS_C)
Project description:The transcription factor nurr1 plays a pivotal role in the development and maintenance of neurotransmitter phenotype in midbrain dopamine neurons. Conversely, decreased nurr1 expression is associated with a number of dopamine-related CNS disorders, including Parkinson’s disease and drug addiction. In order to better understand the nature of nurr1-responsive genes and their potential roles in dopamine neuron differentiation and survival, we used a neural cellular background in which to generate a number of stable clonal lines with graded nurr1 gene expression that approximated that seen in DA cell-rich human substantia nigra. Gene expression profiling data from these nurr1-expressing clonal lines were validated by quantitative RT-PCR and subjected to bioinformatic analyses. The present study identified a large number of nurr1-responsive genes and demonstrated the potential importance of concentration-dependent nurr1 effects in the differential regulation of distinct nurr1 target genes and biological pathways. These data support the promise of nurr1-based CNS therapeutics for the neuroprotection and/or functional restoration of DA neurons.
Project description:We ovexpressed human alpha synuclein alone or together with Nurr1 in mouse primary midbrain cultures and identified the full spectrum of genes whose expression is affected by alpha synuclein, including genes whose expression is normalized after Nurr1 overexpression. Moreover we treated mouse primary midbrain cultures with Bexarotene or short hairpin RNA fro Nurr1, sorted out the dopamine neurons and assessed the effects of Bexarotene and of the Nurr1 downregulation on gene expression.
Project description:The orphan nuclear receptor Nurr1 has been shown to be critical for the development of ventral midbrain dopaminergic neurons. Consequently, the development of ES cells overexpressing Nurr1 has raised hope for the development of cell replacement therapies for Parkinson's Disease to replace degenerated dopaminergic neurons. However, the molecular consequences of Nurr1 on gene expression in these cells remain unknown. To address this, stable, clonal, c17.2 neural stem cell lines were established that overexpressed the orphan nuclear receptor Nurr1 (clone 42 & clone 48) or parental control cell line (puroB & puroD, respectively). Keywords: genetic modification
Project description:Development of meso-diencephalic dopamine (mdDA) neurons requires the combined actions of the orphan nuclear receptor Nurr1 and the paired-like homeobox transcription factor Pitx3. Whereas all mdDA neurons require Nurr1 for expression of Th and survival, dependence on Pitx3 is only displayed by the mdDA subpopulation that will form the substantia nigra (SNc). Previously, we demonstrated that Pitx3-/- embryos lack the expression of the retinoic acid (RA)-generating enzyme Ahd2, which is normally selectively expressed in the Pitx3-dependent DA neurons of the SNc. Restoring RA-signaling in Pitx3-/- embryos revealed a selective dependence of SNc neurons on the presence of RA for differentiation into Th-positive neurons and maintenance throughout embryonic development. Whereas these data are suggestive of an important developmental role for RA in neurons of the SNc, it remained unclear whether other Nurr1 and Pitx3 target genes depend on RA signaling in a manner similar to Th. In search for genes that were affected in Pitx3-deficient mdDA neurons and restored upon embryonic RA treatment, we provide evidence that Delta-like 1, D2R (Drd2) and TH are regulated by Pitx3 and RA signaling, influencing the mdDA terminal differentiated phenotype. Furthermore, we show that regulation of Ahd2-mediated RA-signaling represents only one aspect of the Pitx3 downstream cascade, since Vmat2, Dat, Ahd2 (Aldh1a1), En1, En2 and Cck were unaffected by RA treatment and are (subset) specifically modulated by Pitx3. In conclusion, our data reveal several RA-dependent and -independent aspects of the Pitx3-regulated gene cascade suggesting that Pitx3 acts on multiple levels in the molecular subset-specification of mdDA neurons. RNA was isolated from dissected ventral midbrains of E14.5 Pitx3-/- and Pitx3+/+ mouse embryos. 3 Experimental samples each consisting of 3 Pitx3-/- ventral midbrains were hybridized to reference RNA derived from 10 Pitx3+/+ ventral midbrains
Project description:The orphan nuclear receptor Nurr1 has been shown to be critical for the development of ventral midbrain dopaminergic neurons. Consequently, the development of ES cells overexpressing Nurr1 has raised hope for the development of cell replacement therapies for Parkinson's Disease to replace degenerated dopaminergic neurons. However, the molecular consequences of Nurr1 on gene expression in these cells remain unknown. To address this, stable, clonal, c17.2 neural stem cell lines were established that overexpressed the orphan nuclear receptor Nurr1 (clone 42 & clone 48) or parental control cell line (puroB & puroD, respectively). Experiment Overall Design: Stable neural stem cell lines were grown in proliferating conditions and matched for further microarray analysis based on their similar proliferation rates: Experiment Overall Design: clone 42(c42) vs. puroB(pB) Experiment Overall Design: clone 42(c48) vs. puroD(pD)
Project description:Development of meso-diencephalic dopamine (mdDA) neurons requires the combined actions of the orphan nuclear receptor Nurr1 and the paired-like homeobox transcription factor Pitx3. Whereas all mdDA neurons require Nurr1 for expression of Th and survival, dependence on Pitx3 is only displayed by the mdDA subpopulation that will form the substantia nigra (SNc). Previously, we demonstrated that Pitx3-/- embryos lack the expression of the retinoic acid (RA)-generating enzyme Ahd2, which is normally selectively expressed in the Pitx3-dependent DA neurons of the SNc. Restoring RA-signaling in Pitx3-/- embryos revealed a selective dependence of SNc neurons on the presence of RA for differentiation into Th-positive neurons and maintenance throughout embryonic development. Whereas these data are suggestive of an important developmental role for RA in neurons of the SNc, it remained unclear whether other Nurr1 and Pitx3 target genes depend on RA signaling in a manner similar to Th. In search for genes that were affected in Pitx3-deficient mdDA neurons and restored upon embryonic RA treatment, we provide evidence that Delta-like 1, D2R (Drd2) and TH are regulated by Pitx3 and RA signaling, influencing the mdDA terminal differentiated phenotype. Furthermore, we show that regulation of Ahd2-mediated RA-signaling represents only one aspect of the Pitx3 downstream cascade, since Vmat2, Dat, Ahd2 (Aldh1a1), En1, En2 and Cck were unaffected by RA treatment and are (subset) specifically modulated by Pitx3. In conclusion, our data reveal several RA-dependent and -independent aspects of the Pitx3-regulated gene cascade suggesting that Pitx3 acts on multiple levels in the molecular subset-specification of mdDA neurons.
Project description:In neurons it is assumed mitochondrial replication only occurs in the cell body and then mitochondria have to travel to the periphery. Although mitochondrial replication has been observed to occur away from the cell body, the mechanisms involved are still elusive. Using EdU-labelling in mouse primary neurons, we developed a tool to determine the mitochondrial replication rate. Taking of advantage of microfluidic devices, we confirmed that mitochondrial replication also occurs locally in the periphery of neurons. To achieve this, mitochondria require de novo nuclear-encoded, but not mitochondrial-encoded protein translation. Following a proteomic screen comparing synaptic with non-synaptic mitochondria we identified two elongation factors eEF1A1 and TUFM that were upregulated in synaptic mitochondria. We found that mitochondrial replication is impaired upon downregulation of eEF1A1, and this is particularly relevant in the periphery of neurons.