Project description:Analysis of gene expression differences in three types of mouse motor neurons: (1) those harvested from E13.5 mouse embryos; (2) those derived from embryonic stem cells by directed differentiation; and (3) those made from mouse embryonic fibroblasts by transcription factor reprogramming. Hb9::GFP+ mouse motor neurons were obtained by three methods [(1) dissection of Hb9::GFP-transgenic E13.5 mouse embryo spinal cord; (2) directed differentiation of an Hb9::GFP-transgenic mouse embryonic stem cell line, V6.5; (3) reprogramming of Hb9::GFP-transgenic mouse embryonic fibroblasts by overexpression of 10 transcription factors]. Each type of motor neuron was purified by FACS and harvested in Trizol. Total RNA was purified and prepared for hybridization onto Illumina MouseRef-8.
Project description:RNA sequencing analysis of Hb9::GFP mouse embryonic fibroblasts, Hb9::GFP+ primary mouse embryonic motor neurons at day E13.5, Hb9::GFP+ mouse embryonic stem cell-derived motor neurons, Hb9::GFP+ mouse induced pluripotent stem cell derived motor neurons, and Hb9::GFP+ mouse induced motor neurons generated using transcription factor overexpression. The goal of this project is to evaluate the ability of directed differentiation and lineage conversion techniques to generate a bona fide neuronal subtype.
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: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: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.
Project description:In Caenorhabditis elegans, VA and VB motor neurons arise as lineal sisters but synapse with different interneurons to regulate locomotion. VA-specific inputs are defined by the UNC-4 homeoprotein and its transcriptional corepressor, UNC-37/Groucho, which function in the VAs to block the creation of chemical synapses and gap junctions with interneurons normally reserved for VBs. To reveal downstream genes that control this choice, we have employed a cell-specific microarray strategy that has now identified unc-4-regulated transcripts. One of these genes, ceh-12, a member of the HB9 family of homeoproteins, is normally restricted to VBs. We show that expression of CEH-12/HB9 in VA motor neurons in unc-4 mutants imposes VB-type inputs. Thus, this work reveals a developmental switch in which motor neuron input is defined by differential expression of transcription factors that select alternative presynaptic partners. The conservation of UNC-4, HB9, and Groucho expression in the vertebrate motor circuit argues that similar mechanisms may regulate synaptic specificity in the spinal cord. We employ the mRNA-tagging method to isolate poly(A) RNA from wildtype and unc-37 mutant A-class motor neurons by expressing a 3X FLAG-tagged poly(A) binding protein PAB-1 in DA/VA neurons under control of the unc-4 promoter. A 2-round IVT protocol (modified from the Affymetrix small-sample protocol) was used to convert starting RNA into biotinylated aRNA.
Project description:Although ALS typically presents in mid to late-life, there is increasing evidence for a protracted preclinical period of motor neuron dysfunction. The goal of this study is to identify the earliest gene expression patterns in lower motor neurons that drive selective neuronal vulnerability in a mouse model of ALS. We have implemented transgenic SOD1G93A with a lower motor neuron fluorescent reporter (HB9-GFP) mice to unambiguously isolate spinal motor neurons using FACS for gene expression profiling using RNA sequencing at embryonic day (E)12.5. Data from this transcriptomic study allowed the identification of disturbance in MN homeostasis which occur at the day of birth of spinal motor neurons in SOD1G93A mice. Pathway analysis uncovered several remarkably dysregulated pathways including RNA metabolism disturbance and excitotoxicity. Our findings have the potential to reveal insights into the incipient molecular mechanisms that confer motor neuron vulnerability and therefore may highlight relevant gene targets and pathways for effective intervention in ALS.
Project description:Purpose: Conducted expression profiling by RNA-seq as unbiased screen to identify genes that are altered in motor neurons of PbxMNΔ mice at e12.5 at brachial and thoracic levels of the spinal cord. Because loss of Pbx genes affects MN organization at all rostrocaudal levels, we focused on genes whose profiles were altered at both brachial and thoracic levels. Methods: We compared gene expression profiles in MNs isolated from control Hb9::GFP and PbxMNΔ; Hb9::GFP embryos at e12.5. MNs were purified by FACS, and RNA was extracted from 9 PbxMNΔ; Hb9::GFP and 9 control Hb9::GFP embryos at brachial and thoracic levels using the Arcturus Picopure RNA isolation kit. 10ng of RNA was pooled from 3 RNA samples of each genotype, and used to amplify 100ng of cDNA using Nugene's Ovation RNA-Seq System V2 kit, 100ng of cDNA for each sample was used as in input to prepare 12 bar coded libraries using the Ovation Ultralow Library system. We then performed expression profiling by RNA-seq. The samples were mixed into two pools and run on two 50-nucleotide paired end read rapid run flow cell lanes with the Illumina HiSeq 2500 sequencer. Generating on average 74 and 101 million reads passing filter for brachial and thoracic samples respectively. Results: This analysis yielded 64 brachial and 124 thoracic genes that were differentially expressed with a stringent cutoff of padj.<0.05. Of these genes, we found 31 genes in common between the two, brachial and thoracic, levels of the spinal cord that may play a role in motor neuron columnar organization. Furthermore our expression profiling of control brachial and control thoracic MNs identified 61 genes with (padj.<0.05), that represent distinct molecular profiles of MNs generated at brachial and thoracic levels which may be used to further characterize MNs involved in forelimb and thoracic innervation. Conclusions: Our study represents a detailed transcriptional analysis of embryonic spinal motor neurons and revealed a number of novel motor neuron-specific genes that are under transcriptional regulation of Pbx genes.
Project description:Transcriptional programming of cell identity promises to open up new frontiers in regenerative medicine by enabling the efficient production of clinically relevant cell types. We examine if such cellular programming is accomplished by transcription factors that each have an independent and additive effect on cellular identity, or if programming factors synergize to produce an effect that is not independently obtainable. The combinations of Ngn2-Isl1-Lhx3 and Ngn2-Isl1-Phox2a transcription factors program embryonic stem cells to express a spinal or cranial motor neuron identity respectively. The two alternate expression programs are determined by recruitment of Isl1/Lhx3 and Isl1/Phox2a pairs to distinct genomic locations characterized by two alternative dimeric homeobox motifs. These results suggest that the function of programming modules relies on synergistic interactions among transcription factors and thus cannot be extrapolated from the study of individual transcription factors in a different cellular context. In this study, we functionally characterize induced motor neurons that have been directly generated from ES cells via the forced expression of two different combinations of three transcription factors. Spinal motor neurons are induced via the expression of Ngn2, Isl1, and Lhx3 (iNIL), while cortical motor neurons are induced via the expression of Ngn2, Isl1, and Phox2a (iNIP). Here we profile the gene expression patterns of both types of induced motor neurons, directed differentiation motor neurons, and control cells. In all, 20 microarray experiments are provided in this submission, including 3 replicates of a control condition, 3 replicates of cells that have 24hrs induction of iNIL, 2 replicates of induced spinal motor neurons (induction of iNIL for 48hrs) that have been Hb9-GFP sorted, 3 replicates of induced spinal motor neurons exposed to retinoic acid that have been Hb9-GFP sorted, 3 replicates of motor neurons that have been differentiated in vitro using RA and Hh signalling, 3 replicates of induced cortical motor neurons (induction of iNIP for 48hrs), and 3 replicates of cells in which Isl1 in induced alone (induction of iI for 48hrs). For ChIP-Seq Samples: In this study, we functionally characterize induced motor neurons that have been directly generated from ES cells via the forced expression of two different combinations of three transcription factors. Spinal motor neurons are induced via the expression of Ngn2, Isl1, and Lhx3 (iNIL), while cortical motor neurons are induced via the expression of Ngn2, Isl1, and Phox2a (iNIP). The genome-wide binding of some of the programming factors is characterized here using ChIP-seq. We characterize the binding of Lhx3 and Isl1/2 in iNIL cells, Phox2a and Isl1/2 in iNIP cells, and Isl1/2 in cells in which Isl1 is induced alone (iI). There are 7 Illumina sequence datasets in this submission; one replicate for each of iLhx3-V5 and Isl1/2 in iNIL cells, two replicates for each of iPhox2a-V5 and Isl1/2 in iNIP cells, and one replicate for Isl1/2 in iI cells. An appropriate pseudo-IP control experiment is included.
Project description:In Caenorhabditis elegans, VA and VB motor neurons arise as lineal sisters but synapse with different interneurons to regulate locomotion. VA-specific inputs are defined by the UNC-4 homeoprotein and its transcriptional corepressor, UNC-37/Groucho, which function in the VAs to block the creation of chemical synapses and gap junctions with interneurons normally reserved for VBs. To reveal downstream genes that control this choice, we have employed a cell-specific microarray strategy that has now identified unc-4-regulated transcripts. One of these genes, ceh-12, a member of the HB9 family of homeoproteins, is normally restricted to VBs. We show that expression of CEH-12/HB9 in VA motor neurons in unc-4 mutants imposes VB-type inputs. Thus, this work reveals a developmental switch in which motor neuron input is defined by differential expression of transcription factors that select alternative presynaptic partners. The conservation of UNC-4, HB9, and Groucho expression in the vertebrate motor circuit argues that similar mechanisms may regulate synaptic specificity in the spinal cord.