Molecular characterization of the intact muscle spindle using a multi-omics approach
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE208147 | GEO | 2023/02/10
REPOSITORIES: GEO
Similar Datasets
Project description:The proprioceptive system is essential for the control of coordinated movement, posture and skeletal integrity. The sense of proprioception is produced in the brain using peripheral sensory input from receptors such as the muscle spindle, which detects changes in the length of skeletal muscles. Despite its importance, the molecular composition of the muscle spindle is largely unknown. In this study, we generated comprehensive transcriptomic and proteomic datasets of the entire muscle spindle. We then associated differentially expressed genes with the various tissues composing the spindle using bioinformatic analysis. Immunostaining verified these predictions, thus establishing new markers for the different spindle tissues. Utilizing these markers, we identified the differentiation stages the spindle capsule cells undergo during development. Together, these findings provide comprehensive molecular characterization of the intact spindle as well as new tools to study its development and function in health and disease.
2023-02-17 | PXD035552 | Pride
Project description:Proprioception relies on two main classes of proprioceptive sensory neurons (pSNs). These neurons innervate two distinct peripheral receptors in muscle, muscle spindles (MSs) or Golgi tendon organs (GTOs), and synapse onto different sets of spinal targets, but the molecular basis of their distinct pSN subtype identity remains unknown. We used microarray analysis to compare gene expression profiles between MS- and GTO- innervating proprioceptors.
2015-01-14 | GSE64941 | GEO
Project description:Muscle spindles are skeletal muscle stretch receptors that mediate axial and limb position sensation (proprioception) to the central nervous system. Defective proprioception, often characterized by gait ataxia and poor coordination, is present in a variety of human sensory and motor neuropathies having diverse etiologies. Spindles contain specialized intrafusal muscle fibers that are induced during development by sensory innervation. The molecular events mediating the morphogenetic induction process are poorly characterized but depend upon neuregulins and their cognate ErbB receptor signaling. Recently, we demonstrated that the transcription factor Egr3 is induced and regulated by intrafusal muscle fiber sensory innervation during spindle induction. Moreover, Egr3-deficient mice have impaired spindle morphogenesis and profound gait ataxia. Thus, Egr3 mediated transcription is critical for muscle stretch receptor development and potentially for myotube fate specification.,Egr3 may mediate spindle morphogenesis induced by Neuregulin/ErbB signaling after myotubes are contacted by sensory axons during development. As a starting point for understanding the specific role for Egr3 in this process, we will use a genome wide expression analysis to identify genes regulated (either directly or indirectly) by Egr3 in primary myotubes. It is not practical to examine Egr3 mediated gene expression directly within spindles since they comprise less than 0.1% of the muscle mass. Therefore, gene expression analysis will be examined in primary myotubes grown in vitro. Primary myoblasts isolated from mice and differentiated in vitro are biochemically most similar to extrafusal muscle fibers which do not express Egr3. To identify genes regulated by Egr3 in myotubes, gene expression in myotubes enforced to express full length Egr3 will be compared to gene expression in myotubes enforced to express truncated (transcriptionally inactive) Egr3.,Egr3-deficient mice lack muscle spindles and have profound proprioceptive deficits. Egr3 is specifically expressed in a subset of developing primary myotubes after innervation by sensory axons. Spindle induction is dependent upon sensory/myotube contact which involves sensory axon produced neuregulin and ErbB receptor signaling in the myotube. Shortly after or during induction, Egr3 expression is upregulated and maintained in the nascent myotube/spindle as one of the earliest molecular events know to occur during spindle morphogenesis. We hypothesize that Egr3 mediated transcription is critical for engaging gene programs specific to and essential for, muscle spindle formation. Moreover, Egr3 may be involved in fate specification of myotubes that develop into biochemically and physiologically distinct intrafusal muscle fibers within spindles. To date, the target genes regulated by Egr3 during spindle morphogenesis have not been characterized.,Myoblasts from wild type newborn mice will be isolated and purified. Myoblasts will be plated on collagen coated plates and differentiated in vitro for 7 days. During in vitro differentiation, myoblasts fuse to form multinucleated myotubes that exhibit contractile properties. Egr3 is not expressed in myotubes in vitro, which is consistent with their similarity to extrafusal muscle fibers that also do not express Egr3 in vivo. Only intrafusal fibers of muscle spindles express high levels of Egr3 in this muscle fiber context. Adenoviruses that express full length Egr3 (Egr3wt; transcriptionally active) and truncated Egr3 (Egr3tr; transcriptionally inactive) have been generated and characterized in our laboratory. After 7 days of in vitro differentiation, primary myotubes will be infected with either Egr3wt or Egr3tr adenoviruses. 100% infection is routinely obtained which is confirmed by coexpression of enhanced green fluorescent protein (EGFP). Care will be taken to minimize viral induced toxicity of the myotubes after infection. Myotubes are maintained after infection for 24 hours, after which total RNA is extracted from the cell lysates. The two RNA samples will be used for microarray analysis to identify genes that are upregulated and downregulated by Egr3 in the myotube cellular context. We will repeat the infection, RNA isolation and microarray analysis three times to minimize identifying false positive differentially expressed genes. Differentially expressed genes will be confirmed using real-time PCR. Interesting differentially expressed genes will be examined by in situ hybridization to determine if they are specifically expressed in wild type spindles. Since the identified differentially expressed genes will represent both indirect and direct target genes, we will perform Chromatin Immunoprecipitation (ChIP) from Egr3wt infected myotubes and screen the ChIP DNA library by PCR to determine which gene promoters are directly bound by Egr3.
2007-07-07 | E-GEOD-1998 | biostudies-arrayexpress
Project description:The stretch reflex is a fundamental component of the motor system to orchestrate the coordinated muscle contractions underlying movement. At the heart of this process lie the muscle spindles (MS), specialized receptors finely attuned to fluctuations in tension within intrafusal muscle fibers. The tension variation in the MS triggers a series of neuronal events: an initial depolarization of sensory type Ia afferents that subsequently causes the activation of motoneurons within the spinal cord. This neuronal cascade culminates in the execution of muscle contraction, underscoring a presumed closed-loop mechanism between the muscular and nervous systems. In contrast, surprisingly here we report the discovery of a new population of macrophages with exclusive molecular and functional signatures within the muscle spindle that express the machinery for synthesizing and releasing glutamate. Using mouse intersectional genetics with optogenetics and electrophysiology, we show that muscle spindle macrophages (MSMP) activation drives proprioceptive sensory neurons firing at millisecond timescale with subsequent activation of spinal circuitries, motor neurons, and muscles by a glutamate-dependent mechanism. Additionally, we found that MSMP can also respond to the activation of the stretch reflex circuitry by increasing the expression of glutaminase, allowing them to convert the glutamine released by myocytes during muscle contraction into glutamate. Our results identified a new cellular component, the MSMP, that directly regulates neural activity and muscle contraction. The glutamate-mediated signalling of MSMP and their dynamic response to sensory cues introduces a novel dimension to our understanding of sensation and motor action, potentially offering innovative therapeutic approaches in conditions that affect sensory-motor function.
2024-10-08 | GSE244351 | GEO
Project description:The stretch reflex is a fundamental component of the motor system to orchestrate the coordinated muscle contractions underlying movement. At the heart of this process lie the muscle spindles (MS), specialized receptors finely attuned to fluctuations in tension within intrafusal muscle fibers. The tension variation in the MS triggers a series of neuronal events: an initial depolarization of sensory type Ia afferents that subsequently causes the activation of motoneurons within the spinal cord. This neuronal cascade culminates in the execution of muscle contraction, underscoring a presumed closed-loop mechanism between the muscular and nervous systems. In contrast, surprisingly here we report the discovery of a new population of macrophages with exclusive molecular and functional signatures within the muscle spindle that express the machinery for synthesizing and releasing glutamate. Using mouse intersectional genetics with optogenetics and electrophysiology, we show that muscle spindle macrophages (MSMP) activation drives proprioceptive sensory neurons firing at millisecond timescale with subsequent activation of spinal circuitries, motor neurons, and muscles by a glutamate-dependent mechanism. Additionally, we found that MSMP can also respond to the activation of the stretch reflex circuitry by increasing the expression of glutaminase, allowing them to convert the glutamine released by myocytes during muscle contraction into glutamate. Our results identified a new cellular component, the MSMP, that directly regulates neural activity and muscle contraction. The glutamate-mediated signalling of MSMP and their dynamic response to sensory cues introduces a novel dimension to our understanding of sensation and motor action, potentially offering innovative therapeutic approaches in conditions that affect sensory-motor function.
2024-10-08 | GSE246400 | GEO
Project description:Proprioception relies on two main classes of proprioceptive sensory neurons (pSNs). These neurons innervate two distinct peripheral receptors in muscle, muscle spindles (MSs) or Golgi tendon organs (GTOs), and synapse onto different sets of spinal targets, but the molecular basis of their distinct pSN subtype identity remains unknown. We used microarray analysis to compare gene expression profiles between MS- and GTO- innervating proprioceptors. We generated transgenic mice in which MS and GTO pSNs are labelled with different fluorescent proteins (see de Nooij et al., 2015 for details). We used Fluorescent Activated Cell Sorting (FACS) to isolate the MS and GTO pSN subsets from dissociated DRG from p7-10 transgenic mice. Neurons from multiple FACS experiments were pooled into three samples each for the MS and GTO pSN subset.
2015-01-14 | E-GEOD-64941 | biostudies-arrayexpress
Project description:The precise execution of coordinated movements depends on proprioception, the sense of body position in space. However, the molecular underpinnings of proprioceptive neuron subtype identities are not fully understood. Here we used a single-cell transcriptomic approach to define mouse proprioceptor subtypes according to the identity of the muscle they innervate. We identified and validated molecular signatures associated with proprioceptors innervating back (Tox, Epha3), abdominal (C1ql2), and hindlimb (Gabrg1, Efna5) muscles. We also found that proprioceptor muscle identity precedes acquisition of receptor character and comprise programs controlling wiring specificity. These findings indicate that muscle-type identity is a fundamental aspect of proprioceptor subtype differentiation that is acquired during early development and includes molecular programs involved in the control of muscle target specificity.
2022-10-23 | GSE190605 | GEO
Project description:Muscle spindles are skeletal muscle stretch receptors that mediate axial and limb position sensation (proprioception) to the central nervous system. Defective proprioception, often characterized by gait ataxia and poor coordination, is present in a variety of human sensory and motor neuropathies having diverse etiologies. Spindles contain specialized intrafusal muscle fibers that are induced during development by sensory innervation. The molecular events mediating the morphogenetic induction process are poorly characterized but depend upon neuregulins and their cognate ErbB receptor signaling. Recently, we demonstrated that the transcription factor Egr3 is induced and regulated by intrafusal muscle fiber sensory innervation during spindle induction. Moreover, Egr3-deficient mice have impaired spindle morphogenesis and profound gait ataxia. Thus, Egr3 mediated transcription is critical for muscle stretch receptor development and potentially for myotube fate specification. Egr3 may mediate spindle morphogenesis induced by Neuregulin/ErbB signaling after myotubes are contacted by sensory axons during development. As a starting point for understanding the specific role for Egr3 in this process, we will use a genome wide expression analysis to identify genes regulated (either directly or indirectly) by Egr3 in primary myotubes. It is not practical to examine Egr3 mediated gene expression directly within spindles since they comprise less than 0.1% of the muscle mass. Therefore, gene expression analysis will be examined in primary myotubes grown in vitro. Primary myoblasts isolated from mice and differentiated in vitro are biochemically most similar to extrafusal muscle fibers which do not express Egr3. To identify genes regulated by Egr3 in myotubes, gene expression in myotubes enforced to express full length Egr3 will be compared to gene expression in myotubes enforced to express truncated (transcriptionally inactive) Egr3. Egr3-deficient mice lack muscle spindles and have profound proprioceptive deficits. Egr3 is specifically expressed in a subset of developing primary myotubes after innervation by sensory axons. Spindle induction is dependent upon sensory/myotube contact which involves sensory axon produced neuregulin and ErbB receptor signaling in the myotube. Shortly after or during induction, Egr3 expression is upregulated and maintained in the nascent myotube/spindle as one of the earliest molecular events know to occur during spindle morphogenesis. We hypothesize that Egr3 mediated transcription is critical for engaging gene programs specific to and essential for, muscle spindle formation. Moreover, Egr3 may be involved in fate specification of myotubes that develop into biochemically and physiologically distinct intrafusal muscle fibers within spindles. To date, the target genes regulated by Egr3 during spindle morphogenesis have not been characterized. Myoblasts from wild type newborn mice will be isolated and purified. Myoblasts will be plated on collagen coated plates and differentiated in vitro for 7 days. During in vitro differentiation, myoblasts fuse to form multinucleated myotubes that exhibit contractile properties. Egr3 is not expressed in myotubes in vitro, which is consistent with their similarity to extrafusal muscle fibers that also do not express Egr3 in vivo. Only intrafusal fibers of muscle spindles express high levels of Egr3 in this muscle fiber context. Adenoviruses that express full length Egr3 (Egr3wt; transcriptionally active) and truncated Egr3 (Egr3tr; transcriptionally inactive) have been generated and characterized in our laboratory. After 7 days of in vitro differentiation, primary myotubes will be infected with either Egr3wt or Egr3tr adenoviruses. 100% infection is routinely obtained which is confirmed by coexpression of enhanced green fluorescent protein (EGFP). Care will be taken to minimize viral induced toxicity of the myotubes after infection. Myotubes are maintained after infection for 24 hours, after which total RNA is extracted from the cell lysates. The two RNA samples will be used for microarray analysis to identify genes that are upregulated and downregulated by Egr3 in the myotube cellular context. We will repeat the infection, RNA isolation and microarray analysis three times to minimize identifying false positive differentially expressed genes. Differentially expressed genes will be confirmed using real-time PCR. Interesting differentially expressed genes will be examined by in situ hybridization to determine if they are specifically expressed in wild type spindles. Since the identified differentially expressed genes will represent both indirect and direct target genes, we will perform Chromatin Immunoprecipitation (ChIP) from Egr3wt infected myotubes and screen the ChIP DNA library by PCR to determine which gene promoters are directly bound by Egr3. Keywords: other
2004-11-24 | GSE1998 | GEO
Project description:A series of conditional mouse models of embryonal rhabdomyosarcoma, alveolar rhabdomyosarcoma and spindle cell sarcoma were generated and validated for relavence to corresponding human cancers. Conditional mouse models of embryonal rhabdomyosarcoma, alveolar rhabdomyosarcoma and spindle cell sarcoma were created by activation or deletion of Pax3:Fkhr, p53, Ptch1 or Rb1 genes.
2011-02-17 | E-GEOD-22520 | biostudies-arrayexpress
Project description:The oocytes of many species, both invertebrate and vertebrate, contain a large collection of localized determinants in the form of proteins and translationally inactive maternal mRNAs. However, it is unknown whether mouse oocytes contain localized MmRNA determinants and what mechanisms might be responsible for their control. We collected intact MII oocytes, enucleated MII oocyte cytoplasts (with the spindle removed), and spindle-chromosome complexes which had been microsurgically removed. RNA was extracted, amplified, labeled, and applied to microarrays to determine if any MmRNA determinants were localized to the SCC. We used microarrays to determine whether maternal mRNAs in mouse oocytes are enriched in the meiotic spindle
2013-11-06 | E-GEOD-46875 | biostudies-arrayexpress