Project description:We take advantage of in vitro-derived motor neurons as a paradigm to investigate the cellular level during motor neuron differentiation. In this study, to uncover the abundantly expressed gene in the development of spinal motor neuron, we characterize transcriptomic signatures of HuES (human embryonic stem cell) derived motor neuron .
Project description:We report the comparative gene expression between embryonic stem cell derived cranial and spinal motor neurons and multiple time points after induction and primary cultured ocular and spinal motor neurons, using single cell RNA sequencing.
Project description:Spinal motor neurons deficiency results in a series of devastating disorders such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA) and spinal cord injury (SCI). These devastating disorders are currently incurable, while human pluripotent stem cells (hPSCs) derived spinal motor neurons are promising but suffered by low-efficiency, functional immaturity and lacks of posterior cell identity. In this study, we have established human spinal cord neural progenitor cells (hSCNPCs) via hPSCs differentiated neuromesodermal progenitors (NMPs) and demonstrated the hSCNPCs can be continuously expanded up to 40 passages. hSCNPCs can be rapidly differentiated into posterior spinal motor neurons with high efficiency. The functional maturity has been examined in detail. Moreover, a co-culture scheme which is compatible for both neural and muscular differentiation is developed to mimic the neuromuscular junction (NMJ) formation in vitro. Together, these studies highlight the potential avenues for generating clinically relevant motor neurons and modelling neuromuscular diseases through our defined hSCNPCs.
Project description:We compare transcriptomic profiles of human induced pluripotent stem cells (iPSCs), motor neurons (MNs) in vitro differentiated from iPSCs or human ESCs containing a HB9::GFP reporter for MNs, and human fetal spinal cords. The purpose of this comparison is to assess the extent of molecular similarities between in vitro differentiated MNs and in vivo fetal or adult spinal cord MNs. Data for adult spinal cord MNs are published from other studies: GSE3526, GSE19332, GSE20589, and GSE40438. Human induced pluripotent stem cells, pluripotent stem cell derived motor neurons, and fetal spinal cords for RNA extraction and hybridization on Affymetrix arrays.
Project description:Proximal spinal muscular atrophy (SMA) is an early onset, autosomal recessive motor neuron disease caused by loss of or mutation in SMN1 (survival motor neuron 1). Despite understanding the genetic basis underlying this disease, it is still not known why motor neurons (MNs) are selectively affected by the loss of the ubiquitously expressed SMN protein. Using a mouse embryonic stem cell (mESC) model for severe SMA, the RNA transcript profiles (transcriptomes) between control and severe SMA (SMN2+/+;mSmn-/-) mESC-derived MNs were compared in this study using massively parallel RNA sequencing (RNA-Seq). The MN differentiation efficiencies between control and severe SMA mESCs were similar. RNA-Seq analysis identified 3094 upregulated and 6964 downregulated transcripts in SMA mESC-derived MNs when compared against control cells. Pathway and network analysis of the differentially expressed RNA transcripts showed that pluripotency and cell proliferation transcripts were significantly increased in SMA MNs while transcripts related to neuronal development and activity were reduced. The differential expression of selected transcripts such as Crabp1, Crabp2 and Nkx2.2 was validated in a second mESC model for SMA as well as in the spinal cords of low copy SMN2 severe SMA mice. Furthermore, the levels of these selected transcripts were restored in high copy SMN2 rescue mouse spinal cords when compared against low copy SMN2 severe SMA mice. These findings suggest that SMN deficiency affects processes critical for normal development and maintenance of MNs. RNA profiles were generated from FACS-purified control and SMA mESC-derived motor neurons (n=3/genotype) by deep sequencing using Illumina HighSeq 2500
Project description:Spinal Muscular Atrophy (SMA) is well-known to be caused by mutations in the gene Survival of Motor Neuron 1 (SMN1). Because this gene is ubiquitously expressed, it remains poorly understood why motor neurons (MNs) are one of the most affected cell types. To begin to address this question, we carried out RNA-sequencing studies using fixed, antibody-labeled and purified MNs produced from control and SMA patient-derived induced pluripotent stem cells (iPSCs). We found SMA-specific changes in MNs, including hyper-activation of the endoplasmic reticulum (ER) stress pathway and enhanced apoptosis. Functional studies demonstrated that inhibition of ER stress improves overall MN health and survival in vitro even in MNs with low SMN levels. In SMA mice, we show that systemic delivery of an ER stress inhibitor that crosses the blood-brain-barrier led to preservation of MNs in the spinal cord and prolonged survival of these mice. Therefore, our study implies that selective activation of ER stress underlies MN death in SMA. Moreover, the approach we have taken would be broadly applicable to studying disease-prone human cells in heterogeneous cultures. total RNA collected from ES cell and patient ES cell derived spinal motor neurons
Project description:Spinal and bulbar muscular atrophy (SBMA), also known as Kennedy’s Disease, is a slowly progressive adult-onset neuromuscular disease which results from a polyglutamine (polyQ) encoding CAG repeat expansion within the androgen receptor gene (AR). Despite the ubiquitous expression of the androgen receptor, it is unclear why motor neurons selectively degenerate and there are no effective treatments or disease modifying therapies for this debilitating disease. In order to identify potential therapeutic targets, we set out to establish the genes and molecular pathways involved in early motor neuron dysfunction in SBMA. We therefore undertook global transcriptomic profiling of cultured primary embryonic motor neurons from the spinal cord of AR100 mice, which model SBMA.. Four biological replicate samples were used for genome wide analysis using Affymetrix 430 v2.0 mouse arrays. Data was normalised using therobust multichip average (RMA) algorithm.
Project description:Motor neurons are selectively vulnerable in spinal muscular atrophy (SMA). However, some brainstem motor neuron groups, including oculomotor and trochlear, which innervate the muscles around the eyes, are for unknown reasons spared. Here, we investigate the transcriptional dynamics in discrete neuronal populations in health and SMA to identify mechanisms of vulnerability and resistance. Such mechanisms could reveal targets for future gene therapy studies aimed towards preserving vulnerable motor neurons.
Project description:FUS ALS seems to preferentially affect sMNs, and cognitive dysfunction in FUS ALS is rare. Considering this, we wanted to analyze if cortical neurons behave differently than spinal motor neurons in response to FUS mutations. For this, we used cortical neurons derived from isogenic human induced pluripotent stem cells (hiPSCs) in which either WT or NLS mutant FUS P525L was tagged with eGFP using CRISPR/Cas9 and systematically compared them to sMNs of the identical iPSCs. Phenotypically, mutant FUS cortical neurons showed less impairment of FUS recruitment to DNA damage sites compared to mutant sMNs and less signs of DNA damage, which were similarly found in post mortem tissue. To advance our understanding of finding different molecular mechanisms and pathways related to FUS mutations in ALS disease, we have performed RNA sequencing of FUS ALS cortical and spinal motor neurons and our results revealed basic differences in their transcriptomes. Alternative splicing events in spinal motor neurons were different from cortical neurons also pointing towards DNA damage in FUS ALS.
Project description:The neuromuscular junction (NMJ) is a specialized synapse that allows for the communication between spinal motor neurons and muscle fibers. Maintenance of motor-muscle connectivity at the NMJ is critical for the preservation of muscle strength and coordinated motor function. Unlike injuries that damage the central nervous system, motor neurons can mount a robust regenerative response after peripheral nerve injuries. In contrast, motor neurons selectively degenerate in diseases such as amyotrophic lateral sclerosis (ALS), which leads to progressive muscle wasting and paralysis. To assess how different insults affect motor neurons in vivo, we adapted the RiboTag methodology developed by Sanz et al. to perform ribosomal profiling of mouse motor neurons. Using this strategy we isolated and sequenced motor neuron-specific transcripts from spinal cord tissue following sciatic nerve crush, a model of acute injury and regeneration, and in the SOD1-G93A mouse model of ALS.