Phrenic neuronal determinants screen in M.Musculus [1]
Ontology highlight
ABSTRACT: Expression response after induction of putative phrenic neuronal determinants in ES cells was compared to a pre-determined list of genes over-expressed in FACS-sorted phrenic cells. Transcription factor Pou3f1 was identified as a major determinant of phrenic identity. Cells type individually compared to the overall expression to identify differentially expressed genes patterns
Project description:Expression response after induction of putative phrenic neuronal determinants in ES cell-derived motor neurons was compared to a pre-determined list of genes over-expressed in FACS-sorted primary. Transcription factor Pou3f1 was identified as a major determinant of phrenic identity. Expression in induced cell lines were compared to YFP controls, and over-representation of phrenic genes was computed for the list of differentially expressed genes in each indiced cell lines.
Project description:Expression response after induction of putative phrenic neuronal determinants in ES cells was compared to a pre-determined list of genes over-expressed in FACS-sorted phrenic cells. Transcription factor Pou3f1 was identified as a major determinant of phrenic identity.
Project description:Spinal cord injury leads to impaired motor and sensory functions. After spinal cord injury there is a an initial phase of hypo-reflexia followed by a developing hyper-reflexia, often termed spasticity. Previous studies have suggested a relationship between the reappearence of plateau potentials in motor neurons and the development of spasticity after spinalization. To understand the molecular mechanism behind this phenomenon we examined the transcriptional response of the motor neurons after spinal cord injury. We used a rat tail injury model where a complete transection of the caudal (S2) rat spinal cord leads to an immidate flaccid paralysis of the tail and a subsequent appearence of spasticity 2-3 weeks post injury that develops into strong spasticity after 2 months. Gene expression changes were studied in motor neurons 21 and 60 days after complete spinal transection where the tail exhibits clear signs of spasticity. Tail MNs were retorgradely labelled with flourogold injected into the muscle and intra peritoneally. 5-7 days after tracer injections the spinal cord was dissected out, snab frozen in liquid nitrogen, sliced in 10 um thick slices and fluorescent motor neurons were laser dissected into a collector tube to a total of ca. 50-200 cells pr sample. RNA was then extracted, two round amplified and hybridized to Affymetrix rat 230 2.0 arays. 27 samples were hybridized onto chips, 8 Spi-21, 8 Spi-60, 6 ShamC-21 and 5 ShamC-60.
Project description:Spinal cord injury leads to impaired motor and sensory functions. After spinal cord injury there is a an initial phase of hypo-reflexia followed by a developing hyper-reflexia, often termed spasticity. Previous studies have suggested a relationship between the reappearance of plateau potentials in motor neurons and the development of spasticity after spinalization. To understand the molecular mechanism behind this phenomena we examined the transcriptional response of the motor neurons after spinal cord injury as it progress over time. We used a rat tail injury model where a complete transection of the caudal (S2) rat spinal cord leads to an immediate flaccid paralysis of the tail and a subsequent appearance of spasticity 2-3 weeks post injury that develops into strong spasticity after 2 months. Gene expression changes were studied in motor neurones 0, 2, 7, 21 and 60 days after complete spinal transection. Tail MNs were retrogradely labelled with Fluoro-Gold injected into the muscle and intra peritoneally. 5-7 days after tracer injections the spinal cord was dissected out, snap-frozen in liquid nitrogen, sliced in 10 um thick slices and fluorescent motor neurons were laser dissected into a collector tube to a total of ca. 50-200 cells pr sample. RNA was then extracted, two round amplified and hybridized to Affymetrix rat 230 2.0 arays. 31 samples were hybridized onto chips, 4 Spi-0 (Control), 6 Spi-2, 5 Spi-7, 8 Spi-21 and 8 Spi-60.
Project description:The Crown-of-thorns starfish (COTS) Acanthaster planci feeds on hard corals and its outbreaks are a major cause of destruction of coral communities on the Australian Great Barrier Reef. Whilst population booms and the social behaviour of COTS have been well studied, little is known about the neural mechanisms underlying COTS metabolism and behaviour. One of the major classes of chemical messengers that regulate metabolic and behavioural processes in animals are neuropeptides. Here, we have analysed COTS genome and transcriptome sequence data to identify neuropeptide precursor proteins in this species. Mass spectrometry was employed to identify neuropeptides extracted from radial nerve cords. Forty-nine neuropeptide precursors were identified, including homologs of neuropeptide signaling systems that are evolutionarily conserved throughout the Bilateria.
Project description:Peripheral nerve repair and functional recovery depend on the rate of nerve regeneration and the quality of target reinnervation. It is important to fully understand the cellular and molecular basis underlying the specificity of peripheral nerve regeneration, which means the achieving of respective correct pathfinding and accurate target reinnervation for regrowing motor and sensory axons. In this study, a quantitative proteomic technique, based on isobaric tags for relative and absolute quantitation (iTRAQ) was used to profile the protein expression pattern between single motor and sensory nerves at 14 days after peripheral nerve transection. Among a total of 1259 proteins identified, 176 proteins showed the differential expressions between injured motor and sensory nerves. Quantitative real-time RT-PCR and Western blot analysis were applied to validate the proteomic data on representative differentially expressed proteins. Functional categorization indicated that differentially expressed proteins were linked to a diverse array of molecular functions, including axonogenesis, response to axon injury, tissue remodeling, axon ensheathment, cell proliferation and adhesion, vesicle-mediated transport, response to oxidative stress, internal signal cascade, and macromolecular complex assembly, which might play an essential role in peripheral motor and sensory nerve regeneration. Overall, we hope that the proteomic database obtained in this study could serve as a solid foundation for the comprehensive investigation of differentially expressed proteins between injured motor and sensory nerves and for the mechanism elucidation of the specificity of peripheral nerve regeneration.
Project description:Human pluripotent stem cells are a promising source of diverse cells for developmental studies, cell transplantation, disease modeling, and drug testing. However, their widespread use even for intensely studied cell types like spinal motor neurons, is hindered by the long duration and low yields of existing protocols for in vitro differentiation and by the molecular heterogeneity of the populations generated. We report a combination of small molecules that induce up to 50% motor neurons within 3 weeks from human pluripotent stem cells with defined subtype identities that are relevant to neurodegenerative diseases. Despite their accelerated differentiation, motor neurons expressed combinations of HB9, ISL1 and column-specific markers that mirror those observed in vivo in human fetal spinal cord. They also exhibited spontaneous and induced activity, and projected axons towards muscles when grafted into developing chick spinal cord. Strikingly, this novel protocol preferentially generates motor neurons expressing markers of limb-innervating lateral motor column motor neurons (FOXP1+/LHX3-). Access to high-yield cultures of human limb-innervating motor neuron subtypes will facilitate in-depth study of motor neuron subtype-specific properties, disease modeling, and development of large-scale cell-based screening assays. We analyze 3 samples including 2 positive samples and 1 negative sample. Descriptions are as follow: a) Positive Sample 1: SHH-derived, day 21 GFP-high FACS purified motor neurons.b) Positive Sample 2: S+P-derived, day 21 GFP-high FACS purified motor neurons. c) Negative: S+P condition, day 21 no GFP FACS purified motor neurons
Project description:Here we compare the gene expression profiles of two distict, fluorescently identified neuronal populations, the motor neruons (MN) and the decending commissural interneurons (dCIN) of the neonatal rat spinal cord isolated with laser microdissection. These two populations participate in the neuronal networks in the spinal cord where they have destinct functions in shaping (dCINs) and transferring the output to the muscles (MNs) during locomotion. We wished to determine how the functinal differences in these nerurons are manifested at the gene expression level. Experiment Overall Design: Neurons were retrogradely labelled with rhodamine through application of the tracer to cut axons followed by incubation in oxygenated Ringer solution. Spinal cord were then snap frozen, cryosectioned and fluorescent single cells were laser dissected into a collector tube to a total of ca. 50-200 cells pr sample. RNA was then extracted, two round amplified and hybridized to Affymatrix RNU-34 chips. 22 samples were hybridized onto chips, 7 MNs, 7 CINS and 8 MIX.
Project description:Although many distinct mutations in a variety of genes are known to cause Amyotrophic Lateral Sclerosis (ALS), it remains poorly understood how they selectively impact motor neuron biology and whether they converge on common pathways to cause neural degeneration. Here, we have combined reprogramming and stem cell differentiation approaches with genome engineering and RNA sequencing to define the transcriptional changes that are induced in human motor neurons by mutant SOD1. Mutant SOD1 protein induced a transcriptional signature indicative of increased oxidative stress, reduced mitochondrial function, altered sub-cellular transport as well as activation of the ER stress and unfolded protein response pathways. Functional studies demonstrated that perturbations in these pathways were indeed the source of altered transcript levels. 5 samples, 2 patient-derived SOD1A4V and 3 isogenic control samples where the mutation has been corrected. All samples are motor neurons derived from induced pluripotent stem cells (iPSCs), and isolated after lentiviral infection with an Hb9:RFP construct and FACS purification. Each sample is a separate biological replicate.