Project description:Primary cultures of Cerebellar Granule Neurons (CGNs) have been extensively utilized to examine the signal transduction mechanisms underlying neuronal apoptosis. We conducted whole-genome expression profiling to decipher the transcriptional program controlling the apoptotic/survival switch in cerebellar granule neurons (CGNs) following the induction of apoptosis by serum and potassium deprivation and their rescue by gastric inhibitory polypeptide (Gip), substance p (Sp), insulin-like growth factor-1 (Igf1) or pituitary adenylyl cyclase-activating polypeptide (Pacap). Our results reveal the transcriptional changes intersecting neuronal apoptosis and survival and form the basis for further functional analyses and pharmacological exploitation to identify neuroprotective drugs. After six days âin vitroâ (DIV), extracellular KCl of CGNs was shifted from 25 to 5 mM for neuronal apoptotic death induction. After two washes with serum-free BME containing 5 mM KCl, neurons were incubated with the same medium for 6 h (K5), while control neurons were incubated with serum free medium supplemented with 25 mM KCl (K25). K5 neurons were also treated with a maximal effective dose of Gip, Sp, Igf1 and Pacap. Four biological replicates (derived from the same litter) for each of the experimental conditions (K25, K5, K5 + Gip; K25, K5, K5 + Sp; K25, K5, K5 + Igf1; K25, K5, K5 + Pacap) were analyzed.
Project description:Primary cultures of Cerebellar Granule Neurons (CGNs) have been extensively utilized to examine the signal transduction mechanisms underlying neuronal apoptosis. We conducted whole-genome expression profiling to decipher the transcriptional program controlling the apoptotic/survival switch in cerebellar granule neurons (CGNs) following the induction of apoptosis by serum and potassium deprivation and their rescue by gastric inhibitory polypeptide (Gip), substance p (Sp), insulin-like growth factor-1 (Igf1) or pituitary adenylyl cyclase-activating polypeptide (Pacap). Our results reveal the transcriptional changes intersecting neuronal apoptosis and survival and form the basis for further functional analyses and pharmacological exploitation to identify neuroprotective drugs.
Project description:The cerebellum is a brain structure involved in motor and cognitive functions. The development of the cerebellar cortex (the external part of the cerebellum) is under the control of numerous factors. Among these factors, neuropeptides including PACAP or somatostatin modulate the survival, migration and/or differentiation of cerebellar granule cells. Interestingly, such peptides contributing to cerebellar ontogenesis usually exhibit a specific transient expression profile with a low abundance at birth, a high expression level during the developmental processes, which take place within the first two postnatal weeks in rodents, and a gradual decline toward adulthood. Thus, to identify new peptides transiently expressed in the cerebellum during development, rat cerebella were sampled from birth to adulthood, and analyzed by a semi-quantitative peptidomic approach. A total of 33 peptides were found to be expressed in the cerebellum. Among these 33 peptides, 8 had a clear differential expression pattern during development, 4 of them i.e. cerebellin 2, nociceptin, somatostatin and VGF [353-372], exhibiting a high expression level during the first two postnatal weeks followed by a significative decrease at adulthood. A focus by a genomic approach on nociceptin, confirmed that the precursor mRNA is transiently expressed during the first week of life in granule neurons within the internal granule cell layer of the cerebellum, and showed that the nociceptin receptor is also actively expressed between P8 and P16 by the same neurons. Finally, functional studies revealed a new role for nociceptin, acting as a neurotrophic peptide able to promote the survival and differentiation of developing cerebellar granule neurons.
Project description:Expression analysis was performed with in vitro cultured cerebellar granule neurons (CGNs) isolated from rat brain. The CGNs were culture for four weeks. Each sample was collected after interval of seven days. No treatment was given to any cultured neurons at any time point. The purpose of the experiment was to identify the genes differentially expressed during the senescence of CGNs. The experiment is useful in revealing the senescence associated genetic markers in neurons.
Project description:To establish a new model system with which to study cerebellar granule lienage development and disease, human hbNES cells were differentiated to cerebellar granule neurons over a 56 day period.
Project description:To establish a new model system with which to study cerebellar granule lienage development and disease, human hbNES cells were differentiated to cerebellar granule neurons over a 56 day period.
Project description:To establish a new model system with which to study cerebellar granule lienage development and disease, human hbNES cells were differentiated to cerebellar granule neurons over a 56 day period.
Project description:Mutations in the gene encoding the chromatin remodeler CHD8 are a highly penetrant risk factor for autism spectrum disorder (ASD). Although cerebellar abnormalities have been involved in ASD pathogenesis, the underlying mechanisms of CHD8 in the regulation of cerebellar function has remained unknown, however. Here we show that the cerebellar granule neurons–specific deletion of Chd8 manifests reduced proliferation and differentiation of granule neuron progenitors, leading to cerebellar hypoplasia and motor coordination defects in mice. CHD8 was found to regulate the expression of neuronal genes and to be required for maturation of cerebellar granule neurons. Furthermore, we found that CHD8 is preferentially bound to promoter regions and is necessary for modulation of local chromatin accessibilities at promoter regions of active gene. Our results thus uncover a critical role for CHD8 in cerebellar development and have important implications for understanding the cerebellar contributions to ASD pathogenesis.
Project description:We analysed genes upregulated or down regulated by double deletion of Rac1 and Rac3 (Rac1/Rac3-DKO) in cerebellar granule neurons compared with control, using the external granule layer (EGL) dissected from Rac1/Rac3-DKO cerebellum at P6. Rac1-KO mouse is an inducible knockout, in which Rac1 is specifically deleted in cerebellar granule neurons under control of Atoh1 (also called Math1) promoter. In contrast, Rac3-KO mouse is a conventional/simple KO, in which Rac3 is deleted in all cells in the body. Total RNA from the medial portion of the EGL of Rac1/Rac3-DKO and control cerebella at P6 was extracted using TRIzol (Invitrogen). The quality and quantity of RNA were determined using the Agilent 2100 BioAnalyzer.
