Expression data from epidermal and dorsal root ganglion tissues of wild-type and mutant mice with mechanosensory deficit
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ABSTRACT: A novel mouse line was found to exhibit prominent mechanosensory deficits both behaviorally and at the primary sensory afferents, and exhibits decreased ATP release from the skin. Microarray analysis was used to determine transcriptomic differences that may underlie the mechanosensory deficit in the mutant mouse, and to explore the decreased response of the mutant mouse to an inflammatory insult.
Project description:A variety of mechanosensory neurons are involved in touch, proprioception and pain. Many molecular components of the mechanotransduction machinery subserving these sensory modalities remain to be discovered. Here, we combined recordings of mechanosensitive (MS) currents in mechanosensory neurons with single cell RNA sequencing. In silico analysis of collected data combined with a previous large-scale dataset allowed to link the four identified kinetically distinct MS current subtypes to transcriptomically defined populations of DRG neurons. Moreover, gene expression differential comparison provided a list of candidate genes for mechanotransduction complexes. This dataset constitutes an open-resource to explore further the cell-type-specific determinants of mechanosensory properties.
Project description:Mechanosensory neurons innervating the skin underlie our sense of touch. Fast-conducting, rapidly adapting mechanoreceptors innervating glabrous (non-hairy) skin form Meissner corpuscles, while in hairy skin, they associate with hair follicles, forming longitudinal lanceolate endings. How mechanoreceptors develop axonal endings appropriate for their skin targets is unknown. We report that mechanoreceptor morphologies across different skin regions are indistinguishable during early development but diverge post-natally, in parallel with skin maturation. Neurons terminating along the glabrous and hairy skin border exhibit hybrid morphologies, forming both Meissner corpuscles and lanceolate endings. Additionally, molecular profiles of neonatal glabrous and hairy skin-innervating neurons largely overlap. In mouse mutants with ectopic glabrous skin, mechanosensory neurons form end-organs appropriate for the altered skin type. Finally, BMP5 and BMP7 are enriched in glabrous skin, and signaling through type I bone morphogenetic protein (BMP) receptors in neurons is critical for Meissner corpuscle morphology. Thus, mechanoreceptor morphogenesis is flexibly instructed by target tissues.
Project description:Epithelial-neuronal signaling is essential for sensory encoding in touch, itch and nociception; however, little is known about the release mechanisms and neurotransmitter receptors through which skin cells govern neuronal excitability. Merkel cells are mechanosensory epidermal cells that have long been proposed to activate neuronal afferents through chemical synaptic transmission. We employed a set of classical criteria for chemical neurotransmission as framework to directly test this hypothesis. RNA sequencing of adult Merkel cells demonstrated that they express presynaptic molecules and biosynthetic machinery for adrenergic transmission. Moreover, live-cell imaging directly demonstrated that Merkel cells mediate activity- and VMAT-dependent release of fluorescent catecholamine neurotransmitter analogues. Touch-evoked firing in Merkel-cell afferents was inhibited either by pre-synaptic silencing of SNARE-mediated vesicle release from Merkel cells or by neuronal deletion of b2-adrenergic receptors. Together, these results identify both pre- and postsynaptic mechanisms through which Merkel cells excite mechanosensory afferents to encode gentle touch.
Project description:The molecular identity of touch sensation is still largely unknown. We choose an extrem and very specific example, touch sensation of pennis glan, to study this problem. It's known from previous retro-grade labeling result that only one DRG in rat innervate the pennis glan, which makes it idea for microarry analysis. To clone the mechanosensory receptor specifically or highly expressed in the primary sensory neurons innervating pennis glan. There is a specific mechanosensory receptor in the primary sensory neurons innervating pennis glan. 1. Retrograde labeling the innervating nerve by DiI; 2. Dissect DRGs, dissociate neurons and pick up the fluorescent cells. 3. Pool around 20 positive cells and 50 control cells (big diameter neuron and small to medium diameter neuron respectively), purify total RNA. 4. Two rounds of amplification; 5. Affymetrix analysis
Project description:Angiopoietin-Tie1 signaling is required for lymphatic vascular integrity and both ANGPT2 and TIE1 genetic variants have been associated with lymphedema in patients1, 2. Concurrent with growth-factor signaling, mechanical forces sensed by lymphatic endothelial cells (LECs) are also needed to regulate lymphatics3, 4. How these two pathways might interact in the lymphatic system is unknown. Here, we identified a regulatory network in LECs linking activation of the mechanosensory channel, PIEZO1 to Angiopoietin-Tie signaling and repression of a downstream FOXO1 transcriptional response. RNAseq analysis of dermal LECs from Tie1-deficient embryos showed persistent FOXO1 activity with downregulation of LEC-associated genes including Ccl21a, Foxc2, Gata2 and Gja4, as well as increased expression of the mechanosensory channel, Piezo1. Activation of PIEZO1 in human dermal LECs (HDLECs) by the small molecule agonist, Yoda1, triggered exocytosis of the Tie ligand, Angiopoietin-2 (ANGPT2), activation of Tie/AKT/PI3K signaling and export of FOXO1 out of the nucleus. Our data identify a novel molecular pathway linking mechano-transduction to ANGPT2-Tie1 activity and dynamic modulation of FOXO1 activity needed for patterning and function of the lymphatic system
Project description:The molecular identity of touch sensation is still largely unknown. We choose an extrem and very specific example, touch sensation of pennis glan, to study this problem. It's known from previous retro-grade labeling result that only one DRG in rat innervate the pennis glan, which makes it idea for microarry analysis. To clone the mechanosensory receptor specifically or highly expressed in the primary sensory neurons innervating pennis glan. There is a specific mechanosensory receptor in the primary sensory neurons innervating pennis glan. 1. Retrograde labeling the innervating nerve by DiI 2. Dissect DRGs, dissociate neurons and pick up the fluorescent cells. 3. Pool around 20 positive cells and 50 control cells (big diameter neuron and small to medium diameter neuron respectively), purify total RNA. 4. Two rounds of amplification 5. Affymetrix analysis Keywords: dorsal root ganglion, touch sensatiion
Project description:The sense of touch relies on the detection of mechanical stimuli by specialized sensory neurons. Mechanosensory neurons are generated from neural crest cells, but the scarcity of molecular data has made it difficult to analyze their development and to define the basis of their diversity and function. The transcription factor c-Maf is crucial for mechanosensory function in mice and humans. In particular, c-Maf is required for the development and function of mechanosensory neurons terminating in lanceolate endings, Meissner corpuscles and Pacinian corpuscles. c-Maf is a key transcription factor directing the development and function of rapidly-adapting mechanoreceptors and their end organs.