Project description:The mesencephalic dopaminergic (mDA) cell system is composed by two major groups of projecting cells in the Substantia Nigra (A9 neurons) and the Ventral Tegmental Area (A10 cells). A9 neurons form the nigrostriatal pathway and are involved in regulating voluntary movements and postural reflexes. Their selective degeneration leads to Parkinsons disease (PD). We used cDNA microarrays and nanoCAGE technology coupled with Laser Capture Microdissection (LCM) to characterize the intrinsic physiological properties of A9 DA neurons. Surprisingly, we found that these cells express alpha- and beta- chains of haemoglobin. Here we report that globin-immunoreactivity decorates the majority of A9 DA neurons, a subpopulation of cortical and hippocampal astrocytes as well as mature oligodendrocytes. This pattern of expression was confirmed in different mouse strains, in rat and human. This is the first report showing that haemoglobin is expressed in the Substantia Nigra of human post mortem brain. Our data suggest that the most famed oxygen-carrying globin is not exclusively restricted to the blood, but it may play a role in the normal physiology of the brain as well as in neurodegenerative disorders. To investigate the biological effects of globin expression, alpha- and beta- chains of mouse hemoglobin were overexpressed in MN9D dopaminergic neuroblastoma cell lines. RNA from 4 replicates each of over-expressing cells and of control samples, for a total of 8 samples, were hybridized on Affymetrix GeneChip Mouse Genome 430A 2.0 Arrays. Hybridization of one of the control samples did not pass quality assessment and the sample was therefore excluded from further analysis.
Project description:The mesencephalic dopaminergic (mDA) cell system is composed by two major groups of projecting cells in the Substantia Nigra (A9 neurons) and the Ventral Tegmental Area (A10 cells). A9 neurons form the nigrostriatal pathway and are involved in regulating voluntary movements and postural reflexes. Their selective degeneration leads to Parkinson’s disease (PD). We used cDNA microarrays and nanoCAGE technology coupled with Laser Capture Microdissection (LCM) to characterize the intrinsic physiological properties of A9 DA neurons. Surprisingly, we found that these cells express alpha- and beta- chains of haemoglobin. Here we report that globin-immunoreactivity decorates the majority of A9 DA neurons, a subpopulation of cortical and hippocampal astrocytes as well as mature oligodendrocytes. This pattern of expression was confirmed in different mouse strains, in rat and human. This is the first report showing that haemoglobin is expressed in the Substantia Nigra of human post mortem brain. Our data suggest that the most famed oxygen-carrying globin is not exclusively restricted to the blood, but it may play a role in the normal physiology of the brain as well as in neurodegenerative disorders.
Project description:Dissect the transcriptional consequences of neuroinflammation and the role of the kinase LRRK2 in regulating neuronal responses in human induced pluripotent stem cell (hiPSC)-derived neurons exposed to pro-inflammatory conditions relevant to Parkinson’s disease (PD) and Alzheimer’s disease (AD).Dopaminergic neurons (PD context) and cholinergic neurons (AD context) were differentiated from hiPSCs and subsequently cultured in glial-conditioned medium containing either α-synuclein pre-formed fibrils (α-syn pffs) or amyloid-β (Aβ) fibrils, for PD and aAD respectively. Neuronal cultures were exposed to inflammed media to model chronic inflammatory stress.
Project description:Our recent single-cell sequencing of most adult Drosophila circadian neurons indicated notable and unexpected heterogeneity. To address whether other populations are similar, we sequenced a large subset of adult brain dopaminergic neurons. Their gene expression heterogeneity is similar to that of clock neurons, i.e., both populations have two to three cells per neuron group. There was also unexpected cell-specific expression of neuron communication molecule messenger RNAs: G protein–coupled receptor or cell surface molecule (CSM) transcripts alone can define adult brain dopaminergic and circadian neuron cell type. Moreover, the adult expression of the CSM DIP-beta in a small group of clock neurons is important for sleep. We suggest that the common features of circadian and dopaminergic neurons are general, essential for neuronal identity and connectivity of the adult brain, and that these features underlie the complex behavioral repertoire of Drosophila.
Project description:In genomes of modern fish and amphibia α- and β- globin genes are grouped at a single locus that may resemble the ancestral one and is syntenic to α-globin locus of modern warm-blooded vertebrates. In Danio rerio, the major locus of α/β globin genes comprises two subclusters, one of them harboring genes expressed in adult and the other – genes expressed in embryonic and larval erythrocytes. The results of our previous study suggested that the adult subcluster of this locus has evolved into α-globin gene domain of vertebrate animals. Here we studied how adult and embryo-larval genes of Danio rerio major globin gene locus are repressed in fibroblasts. The results obtained suggest that that at least some of the globin genes present within the adult subcluster are repressed by Polycomb similarly to human α-globin genes. Furthermore, within two α/β gene pairs repression of α-type and β-type genes appears to be mediated by different mechanisms as increasing the level of histone acetylation can activate transcription of only β-type genes.