Spatial transcriptomics of human dorsal root ganglia from subjects with a history of diabetes
Ontology highlight
ABSTRACT: Visium spatial RNA sequencing was performed on 16 human dorsal root ganglia (DRG) tissue sections collected from 7 different DRGs, from 6 human subjects with a history of diabetes.
Project description:During embryogenesis, nociceptive sensory neurons of the dorsal root ganglia depend intimately on Nerve Growth Factor (NGF) for neuronal survival, maturation and target innervation. NGF is a secreted molecular signal synthesized by neuronal target tissues. In developing nociceptors, NGF engages the receptor tyrosine kinase TrkA to activate a gene transcriptional program involving the regulation of hundreds of transcripts. To identify NGF-dependent genes in developing mouse nociceptors, we have designed and performed two separate microarray screens to compare gene expression profiles of DRG neurons either with or lacking NGF signaling. For the first screen comparing DRGs of BaxM-bM-^HM-^R/M-bM-^HM-^R and NgfM-bM-^HM-^R/M-bM-^HM-^R; BaxM-bM-^HM-^R/M-bM-^HM-^R mice, DRGs were dissected and pooled from E14.5 NgfM-bM-^HM-^R/M-bM-^HM-^R; BaxM-bM-^HM-^R/M-bM-^HM-^R and BaxM-bM-^HM-^R/M-bM-^HM-^R embryos. Total RNA was extracted and directly subjected to microarray analysis. For the second screen comparing mouse DRG explants grown in the presence or absence of NGF, E13.5 mouse DRG explants were cultured for two days with 50 ng/ml of either NGF or NT3. Total RNA was extracted and then subjected to microarray analysis.
Project description:Nerve injury induces long-lasting pathological pain, namely neuropathic pain (NP), which is dysfunction of the whole pain transmission process, including dorsal root ganglia (DRG) in peripheral nerve system (PNS). Melatonin is well known over a long period of time as hormone of circadian rhythm closely related with the various aspects of pain conditions. Melatonin and melatonin related receptors (MTR1A and MTR1B) exerted amazing analgesic effect in many acute and chronic pain experimental studies, including electrically induced pain, thermally induced pain, mechanical induction of pain and chemical induction of pain. However, the anti-nociceptive action of melatonin in NP is still controversial and unclear. In the present study, our research firstly demonstrated the expression of melatonin receptors in the DRGs, and what more interesting is that MTR1A and MTR1B have a completely different cell type location (MTR1A in the satellite cells and MTR1B in the neurons). In order to get a basic glance at the effects of melatonin and MTR1B on the DRG neurons, a microarray analysis is applied to screen the pain related different expression genes in the primary DRGs cultured neurons with treatment of 1mM melatonin, 100μM MTR1B agonist 8-M-PDOT or vehicle (1% ethanol of normal saline). Subsequent examination was performed, and the finding suggested that melatonin suppressed neuropathic pain via MTR1B dependent and independent pathways in dorsal root ganglia neurons. And MTR1B in DRG may be a potential therapeutic target for NP.
Project description:Visium Spatial Gene Expression by the 10X genomics protocol was performed on 2 sections of human DRG tissue to elucidate the spatial transcriptomic organization.
Project description:Chronic, often intractable pain is caused by neuropathic conditions such as peripheral nerve injury (PNI) and spinal cord injury (SCI). These conditions are associated with alterations in gene and protein expression correlated with functional changes in somatosensory neurons having cell bodies in dorsal root ganglia (DRGs). Most studies of DRG transcriptional alterations have utilized PNI models where axotomy-induced changes important for regeneration may overshadow changes that drive neuropathic pain. Both PNI and SCI produce DRG neuron hyperexcitability linked to pain, but contusive SCI produces little peripheral axotomy or peripheral nerve inflammation. Thus, comparison of transcriptional signatures of DRGs across PNI and SCI models may highlight pain-associated transcriptional alterations that don’t depend on peripheral axotomy and associated effects such as peripheral Wallerian degeneration. Data from our rat thoracic SCI experiments were combined with meta-analysis of whole-DRG RNA-seq datasets from prominent rat PNI models. Striking differences were found between transcriptional responses to PNI and SCI, especially in regeneration-associated genes and long noncoding RNAs. Many transcriptomic changes after SCI were also found after corresponding sham surgery, indicating they were caused by injury to surrounding tissue rather than to the spinal cord itself. Another unexpected finding was of few transcriptomic similarities between any rat neuropathic pain model and the only reported transcriptional analysis of human DRGs linked to neuropathic pain. These findings show that DRGs exhibit complex transcriptional responses to central and peripheral neural and tissue injury. Although few genes in DRG cells show similar changes in gene expression across all these painful conditions, the few widely shared transcriptional alterations promise novel insights into fundamental mechanisms within DRGs that can drive neuropathic pain.
Project description:Gene expression profiling was carried out to compare labeled cRNA derived from 3 experimental groups. Group 1 was mRNA extracted from wild type dorsal root ganglia (DRG) taken from mice 10-12 weeks of age, Group 2 was mRNA extracted from DRG taken from NT-4 -/- mice of 4-5 weeks of age. Group 3 was mRNA extracted from DRGs taken from NT-4 -/- mice of 12 weeks of age. In all cases mRNA was extracted from 6-10 mice per group. The experiment was carried out a total of three times.
Project description:Transcription factor Meis1 regulates DRG development. We study Meis1 function through assessing whole genome transcriptional profiling of mouse DRG. We used microarrays to examine gene expression in control and Meis1 mutant DRGs.
Project description:Spinal cord injury (SCI) is a devastating clinical condition resulting in significant disabilities for affected individuals. Apart from local injury within the spinal cord, SCI patients develop a myriad of complications characterized by multi-organ dysfunction. Some of the dysfunctions are directly related to the disrupted integrity of sensory afferents from DRGs, which signal to both the spinal cord and peripheral organs. Some classes of DRG neurons undergo axonal sprouting both peripherally and centrally after spinal cord injury. Such physiological and anatomical re-organization of afferent axons after SCI contributes to both adaptive and maladaptive plasticity, which may be modulated by activity/exercise. In this study, we collected comprehensive gene expression data in whole dorsal root ganglia (DRGs) throughout the levels below the injury comparing the effects of SCI with and without activity/exercise.
Project description:Axonal regeneration is enhanced by prior conditioning peripheral nerve lesions. Here we show that Xenopus dorsal root ganglia (DRGs) with attached peripheral nerves (PN-DRGs) can be conditioned in vitro, thereafter showing enhanced axonal growth in response to neurotrophins, similar to preparations conditioned by axotomy in vivo. In contrast to freshly dissected preparations, conditioned PN-DRGs show abundant neurotrophin-induced axonal growth in the presence of actinomycin D, suggesting synthesis of mRNA encoding proteins necessary for axonal elongation occurs during the conditioning period, and this was confirmed by oligonucleotide micro-array analysis.
Project description:Single cell RNAseq was performed on naïve adult mouse lumbar dorsal root ganglia (DRG) cells. Neuronal and non-neuronal cell populations were identified.
Project description:To explored the altered genes during the axon regeneration of rat dorsal root ganglia neurons, we utilized Gene Expression Array to find out the altered expression of genes in cultured DRG neurons at different times. When we digest the cells from rat DRGs with enzymes, we only get the cell bodies of neurons without axons. During the axons re-growth after the neurons planted, it must be amount of genes expression will changed. However, we still not fully understand which genes will changed and the function of these genes. In addition, this cell model could mimic the regeration of sciatic nerve after injure in vivo, which is still a challenge in clinical.