Project description:Cultured adult mouse dorsal root ganglia (DRG) cells exhibit glial sensory progenitor properties in vitro. Therefore, they might be a good starter cell for reprogramming into sensory neurons. Here, we infected them with the retroviral vector Neurog2-Neurog1-DsRed to induce sensory neuron development and analyzed by scRNAseq at 14 days post infection whether infected cells show properties of sensory neurons such as nociceptors. After 10x Genomics, data analysis of 4,549 individual cells indicated the generation of neurons, but at an immature cell state.
Project description:We identified Dynlrb1 as an essential gene for sensory neuron survival and performed RNA sequencing to identify the molecular mechanism mediating the role of Dynlrb1 in sensory neuron survival.
Project description:Amyotrophic lateral sclerosis (ALS) is primarily characterized by motor neuron degeneration, but accumulating evidence suggests that sensory neurons are also affected. To investigate early sensory neuron dysfunction in ALS, we performed bulk RNA sequencing of dorsal root ganglia (DRG) isolated from SOD1-G93A transgenic mice and wild-type controls at disease onset. This dataset provides transcriptomic profiles that reveal molecular alterations associated with ALS-related sensory neuron pathology.
Project description:The richness of our somatosensory experience is reflected in the functional diversity of somatic sensory neurons. Single-cell sequencing (scRNA) of sensory neurons has revealed a molecular basis for such diversity1–3. However, sensory neuron diversity has yet to be captured at the level of the proteome. Here, we combined electrophysiology with deep visual proteomics (DVP)4 to quantify over 6,000 proteins from phenotypically-defined sensory neurons in mice and identified proteomic markers of sensory neuron subtypes. Comparative analysis revealed both concordance and meaningful divergence between transcriptomes and proteomes. We further show that up to 3,000 proteins can be quantified from one-fourth of a single neuron, demonstrating subset-specific protein signatures. In culture, nociceptive neurons can be acutely sensitized to mechanical stimuli by nerve growth factor (NGF) which normally drives inflam-matory pain in vivo5. Indeed, overnight exposure of peptidergic nociceptors to NGF and a pro-tein kinase C (PKC) activator produced functional sensitization associated with proteome changes. Functional knockdown experiments identified the up-regulated B3GNT2 enzyme as a potential effector of nociceptor sensitization. In summary, we present a high-resolution proteomic resource linking molecular identity to function, enabling the discovery of mechanisms un-derlying somatic sensation and pain sensitization.
Project description:Neuronal activity-dependent transcription couples sensory experience to adaptive responses of the brain including learning and memory. Mechanisms of activity-dependent gene expression including alterations of the epigenome have been characterized. However, the fundamental question of whether and how sensory experience remodels chromatin architecture in the adult brain in vivo to induce neural code transformations and learning and memory remains to be addressed. Here, in vivo calcium imaging, optogenetics, and pharmacological approaches reveal that granule neuron activation in the anterior dorsal cerebellar vermis (ADCV) plays a crucial role in a novel delay tactile startle learning paradigm in mice. Strikingly, using large-scale transcriptome and chromatin profiling, we have discovered that activation of the motor learning-linked granule neuron circuit reorganizes neuronal chromatin including through long-distance enhancer-promoter and transcriptionally active compartment interactions to orchestrate distinct granule neuron gene expression modules. Conditional CRISPR knockout of the chromatin architecture regulator Cohesin in ADCV granule neurons in adult mice disrupts activity-dependent transcription and motor learning. These findings define how sensory experience patterns chromatin architecture and neural circuit coding in the brain to drive motor learning.
Project description:This project’s aim was to compare the transcriptional profiles of olfactory sensory neurons in Drosophila melanogaster in order to identify novel genes that specify neuron-specific functions/phenotypes or may otherwise be involved in the development of the olfactory system. The isolation of sufficient numbers of intact olfactory sensory neurons (OSN) from the antenna of Drosophila melanogaster has so far limited single-cell transcriptomic approaches being applied to the adult fly antenna. Targeted DamID (TaDa) provides an alternative approach for profiling transcriptional activity in a cell-specific manor that bypasses the need for isolating OSN. Using the Gal4/UAS system, we applied TaDa to seven OSN populations and compared differences in Pol II occupancy for genes across these datasets.
Project description:Chronic tendinopathy is typified by persistent tendon-associated pain, transmitted by local nociceptive neurons. However, the function of somatosensory neurons in the development of tendinopathy is entirely unknown. Here, we show that sensory neurons grow into the tendon proper across models of chronic tendinopathy. Three complementary surgical and transgenic mice models of disrupted sensory nerve growth were next utilized. Conditional deletion of Nerve growth factor (NGF) in macrophages (Ngf Csfr1) or inactivation of its high affinity receptor Tropomyosin receptor kinase A (TrkA) on sensory neurons led to severely worsened tendinopathy. A sensory-only sural nerve denervation model phenocopied these results, including heightened macrophage infiltration and tenocyte apoptosis. Single-cell RNA sequencing (scRNA-seq) of tendinous tissue identified defective tenocyte differentiation and altered macrophage migration and polarization with surgical denervation. Retrograde neuronal tracing in combination with scRNA-seq of corresponding dorsal root ganglia (DRG) tissues identified the profile of tendon-specific innervation, which included CGRP+ nociceptors among other neuron types. Finally, neuron-tendon interaction analyses implicated neuron-derived fibroblast growth factor 1 (FGF1) as a potent regulator of tendon repair, a finding experimental confirmed with tendon organ culture. Collectively, our findings demonstrate that peripheral afferent neural networks induce a protective effect in chronic tendinopathy by secreting FGF1, and that targeting this pathway may offer therapeutic strategies to enhance tendon repair.