Isl1-Lhx3 fusion specifies motor neuron fate by inducing motor neuron genes and concomitantly suppressing the interneuron programs
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE35510 | GEO | 2012/02/03
SECONDARY ACCESSION(S): PRJNA152319
REPOSITORIES: GEO
Similar Datasets
Project description:Combinatorial transcription codes generate the myriad of cell types during development, and thus likely provide crucial insights into directed differentiation of stem cells to a specific cell type. The LIM-complex composed of Isl1 and Lhx3 directs the specification of spinal motor neurons (MNs) in embryos. Here, we report that Isl1-Lhx3, a LIMcomplex-mimicking fusion, induces a signature of MN transcriptome and concomitantly suppresses interneuron differentiation programs, thereby serving as a potent and specific inducer of MNs in stem cells. We show that an equimolar ratio of Isl1 and Lhx3 and the LIM-domain of Lhx3 are crucial for generating MNs without upregulating interneuron genes. These led us to design Isl1-Lhx3, which maintains the desirable 1:1 ratio of Isl1 and Lhx3 and the LIM-domain of Lhx3. Isl1-Lhx3 drives MN differentiation with high specificity and efficiency in the spinal cord and embryonic stem cells, bypassing the need for sonic hedgehog. RNA-seq analysis revealed that Isl1-Lhx3 induces the expression of a battery of MN genes that control various functional aspects of MNs, while suppressing key interneuron genes. Our studies uncover a highly efficient method for directed MN generation and MN gene networks. Our results also demonstrate a general strategy of utilizing embryonic transcription complexes for producing specific cell types from stem cells. Examine the RNA expression profiles of inducible motor neurons-embryonic stem cells (iMN-ESCs) with or without Dox treatment, with biological duplicates.
2012-02-03 | E-GEOD-35510 | biostudies-arrayexpress
Project description:The motor neuron (MN)–hexamer complex consisting of LIM homeobox 3, Islet-1, and nuclear LIM interactor is a key determinant of motor neuron specification and differentiation. To gain insights into the transcriptional network in motor neuron development, we performed a genome-wide ChIP-sequencing analysis and found that the MN–hexamer directly regulates a wide array of motor neuron genes by binding to the HxRE (hexamer response element) shared among the target genes. Interestingly, STAT3-binding motif is highly enriched in the MN–hexamer–bound peaks in addition to the HxRE. We also found that a transcriptionally active form of STAT3 is expressed in embryonic motor neurons and that STAT3 associates with the MN–hexamer, enhancing the transcriptional activity of the MN–hexamer in an upstream signal-dependent manner. Correspondingly, STAT3 was needed for motor neuron differentiation in the developing spinal cord. Together, our studies uncover crucial gene regulatory mechanisms that couple MN–hexamer and STAT-activating extracellular signals to promote motor neuron differentiation in vertebrate spinal cord. To explain our experimental scheme briefly, we are interested in finding target sites for the dimer of transcription factors Isl1 and Lhx3. To mimic the biological activity of Isl1/Lhx3 dimer, we made Isl1-Lhx3 fusion and found that Isl1-Lhx3 has a potent biological activity in multiple systems (i.e. generation of ectopic motor neurons). Then we made ES cell line that induces Flag-tagged Isl1-Lhx3 expression upon Dox treatment. These *mouse* ES cells differentiate to motor neurons (iMN-ESCs) when treated with Dox following EB formation. To identify genomic binding sites of Isl1-Lhx3 (Flag-tagged), we performed ChIP with Flag antibody (pull down of Flag-Isl1-Lhx3) in ES cells treated with Dox. ChIP with Flag antibody in ES cells treated with vehicle (no Dox) was done as a negative control in parallel, and sequenced along with +Dox sample. We have done these experiments twice (two sets).
2013-09-19 | E-GEOD-50993 | biostudies-arrayexpress
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.
2013-07-04 | E-GEOD-31456 | biostudies-arrayexpress
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.
2013-07-04 | GSE31456 | GEO
Project description:Motor neuron (MN), together with interneuron, are the two major neuronal types in spinal cord. MNs control muscle movement and are essential for breathing, walking and fine motor skills. Malfunction of MNs is frequently associated with neuronal diseases such as spinal muscular atrophy and amyotrophic lateral sclerosis. To establish normal function, MNs need to be differentiated properly from neural progenitor cells. Thus, it is of great importance to study the mechanism for MN specification. This study focuses on Mnx1 - a conserved homeobox transcription factor gets expressed during MN specification. Mnx1 is also the most widely used MN marker. Previous studies reported that Mnx1 mutation in mouse causes early lethality - probably by affecting the controlling over respiratory system. However, the exact role of Mnx1 for MN identity remains poorly understood. Taking advantage of a recently developed in vitro model for efficient MN induction from mouse ES cells, we combined experimental and OMICs techniques to systematically investigate the molecular function of Mnx1. We identified thousands of Mnx1 binding sites - many are co-bound by core MN factor Lhx3 and Isl1 and lack active histone marks. Disruption of Mnx1 causes increased expression of 85 genes - while only 14 genes get down-regulated. Up-regulated genes are enriched with neuronal functions, usually get expressed during MN differentiation, and tend to have higher expression in motor neurons and brain compared with other tissues – indicating Mnx1 may fine tune neuronal genes to desired level. However, only a dozen of regions with increased H3K27ac marks are bound by Mnx1, and only two up-regulated genes (Pbx3 and Pou6f2) are identified as putative direct targets of Mnx1 - both are core neuronal factors with the potential to regulate other differential neuronal genes. These results suggest that Mnx1 may contribute to MN identity by fine-tuning the expression of many neuronal genes through direct regulation of a few core neuronal transcription factors. In summary, this study represents the first systematic investigation about the molecular function of the core MN factor Mnx1. It clarifies the mechanism of Mnx1 for MN identity, and also improves the understanding about the regulation mode of homeobox transcription factors.
2021-12-31 | GSE143161 | GEO
Project description:The motor neuron (MN)–hexamer complex consisting of LIM homeobox 3, Islet-1, and nuclear LIM interactor is a key determinant of motor neuron specification and differentiation. To gain insights into the transcriptional network in motor neuron development, we performed a genome-wide ChIP-sequencing analysis and found that the MN–hexamer directly regulates a wide array of motor neuron genes by binding to the HxRE (hexamer response element) shared among the target genes. Interestingly, STAT3-binding motif is highly enriched in the MN–hexamer–bound peaks in addition to the HxRE. We also found that a transcriptionally active form of STAT3 is expressed in embryonic motor neurons and that STAT3 associates with the MN–hexamer, enhancing the transcriptional activity of the MN–hexamer in an upstream signal-dependent manner. Correspondingly, STAT3 was needed for motor neuron differentiation in the developing spinal cord. Together, our studies uncover crucial gene regulatory mechanisms that couple MN–hexamer and STAT-activating extracellular signals to promote motor neuron differentiation in vertebrate spinal cord.
2013-09-19 | GSE50993 | GEO
Project description:During development, two cell-types born from closely related progenitor pools often express the identical transcriptional regulators despite their completely distinct characteristics. This phenomenon highlights the necessity of the mechanism that operates to segregate the identities of the two cell-types throughout differentiation after initial fate commitment. To understand this mechanism, we investigated the fate specification of spinal V2a interneurons, which share important developmental genes with motor neurons (MNs). Here we demonstrate that the paired homeodomain factor Chx10 functions as a critical determinant for V2a fate and is required to consolidate V2a identity in postmitotic neurons. Chx10 actively promotes V2a fate, downstream of the LIM-homeodomain factor Lhx3, while concomitantly suppressing MN developmental program by preventing the MN-specific transcription complex from binding and activating MN genes. This dual activity enables Chx10 to effectively separate V2a and MN pathways. Together, our study uncovers a widely applicable gene regulatory principle for segregating related cell fates. RNA samples from Chx10-ESC-derived MNs were prepared for sequencing according to the Illumina protocol, and sequenced on the Illumina HiSeq 2000. We will then compare the transcriptome changes between -Dox (no Chx10) and +Dox (Chx10) in order to identify genes rregulated by Chx10.
2016-07-28 | E-GEOD-83873 | biostudies-arrayexpress
Project description:During development, two cell-types born from closely related progenitor pools often express the identical transcriptional regulators despite their completely distinct characteristics. This phenomenon highlights the necessity of the mechanism that operates to segregate the identities of the two cell-types throughout differentiation after initial fate commitment. To understand this mechanism, we investigated the fate specification of spinal V2a interneurons, which share important developmental genes with motor neurons (MNs). Here we demonstrate that the paired homeodomain factor Chx10 functions as a critical determinant for V2a fate and is required to consolidate V2a identity in postmitotic neurons. Chx10 actively promotes V2a fate, downstream of the LIM-homeodomain factor Lhx3, while concomitantly suppressing MN developmental program by preventing the MN-specific transcription complex from binding and activating MN genes. This dual activity enables Chx10 to effectively separate V2a and MN pathways. Together, our study uncovers a widely applicable gene regulatory principle for segregating related cell fates. ChIP DNA samples from Chx10-ESC-derived MNs were prepared for sequencing according to the Illumina protocol, and sequenced on the Illumina HiSeq 2000. The peak calling was conducted with MACS software (Zhang et al., 2008). MEME-ChIP Suite (Bailey et al., 2009; Machanick and Bailey, 2011) and TOMTOM algorithm (Gupta et al., 2007) was used for motif analysis.
2016-07-28 | E-GEOD-83872 | biostudies-arrayexpress
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
2015-09-01 | E-GEOD-69175 | biostudies-arrayexpress
Project description:Locomotion requires precise control of the strength and speed of muscle contraction and is achieved by recruiting functionally-distinct subtypes of motor neurons (MNs). MNs are essential to movement and differentially susceptible in disease, but little is known about how MNs acquire functional subtype-specific features during development. Using single-cell RNA profiling in embryonic and larval zebrafish, we identify novel and conserved molecular signatures for MN functional subtypes, and identify genes expressed in both early post-mitotic and mature MNs. Assessing MN development in genetic mutants, we define a molecular program essential for MN functional subtype specification. Two evolutionarily-conserved transcription factors, Prdm16 and Mecom, are both functional subtype-specific determinants integral for fast MN development. Loss of prdm16 or mecom causes fast MNs to develop transcriptional profiles and innervation similar to slow MNs. These results reveal the molecular diversity of vertebrate axial MNs and demonstrate that functional subtypes are specified through intrinsic transcriptional codes.
2023-08-24 | GSE240026 | GEO