Project description:Chronic pain affects 20-30% of the population and imposes a significant socio-economic burden as it is often accompanied by substantial emotional comorbidities such as anxiety and depression. Yet, the mechanisms underlying the interactions between the sensory and emotional aspects of chronic pain remain poorly understood. Here, we investigated the role of FKBP51, a regulator of the stress response, in mediating both sensory and emotional symptoms of chronic pain. Inhibition of FKBP51, via genetic deletion or pharmacological blockade, in persistent joint pain reduced fast-onset sensory, functional and activity-related symptoms, as well as late anxio-depressive comorbidities. FKBP51 inhibition after the establishment of the hypersensitive state provided only temporary symptoms relief, while acute inhibition at disease onset protected from the full development of sensory and anxio-depressive symptoms for up to 6 months. Our results also indicated that early pain symptoms could predict the late sensory and emotional outcomes of chronic pain. RNA sequencing of spinal cord tissue revealed that late FKBP51 inhibition transiently altered nociceptive genes associated with mechanical hypersensitivity. In contrast, early inhibition persistently downregulated the Naaa gene, a key regulator of the transition to chronic pain, and reorganized spinal cilia. Our results indicate that early FKBP51 inhibition after injury can persistently reduce chronic pain and prevent the onset of associated emotional comorbidities by modulating critical spinal neurobiological pathways that play pivotal roles in the transition to chronic pain.
Project description:Chronic pain is a persistent unpleasant sensation that produces pathological synaptic plasticity in the central nervous system. Some of the studies demonstrate that the anterior cingulate cortex (ACC) is a critical area for nociceptive and chronic pain processing. Our previous study revealed that animal models of chronic pain alter excitatory and inhibitory synaptic transmission in the ACC. However, it is not clear what molecules are involved in the alterations of synaptic plasticity in the ACC of chronic pain models. To identify genes with altered expression in the ACC of a chronic pain model, whole transcriptome analysis were performed. In addition to the ACC, whole transcriptome analysis was also performed in the hippocampus, a brain region that has not been reported to be associated with chronic pain. Complete freund's adjuvant (CFA, Sigma-Aldrich, #F5881) into the left hind paw was used for induce chronic inflammatory pain in this study.
Project description:There is an imminent need for safe and efficient chronic pain medications. Regulator of G-protein signaling 4 (RGS4) is a multi-functional signal transduction protein, widely expressed in the pain matrix. Here, we demonstrate that RGS4 plays a prominentrole in the maintenance of chronic pain symptoms in male and female mice. Using genetically modified mice, we show a dynamicrole of RGS4 in recovery from symptoms of sensory hypersensitivity deriving from hindpaw inflammation or hindlimb nerveinjury. We also demonstrate an important role of RGS4 actions in gene expression patterns induced by chronic pain states in themouse thalamus. Our findings provide novel insight into mechanisms associated with the maintenance of chronic pain states anddemonstrate that interventions in RGS4 activity promote recovery from sensory hypersensitivity symptoms.
Project description:Distinct types of dorsal root ganglion sensory neurons may have unique contributions to chronic pain. Identification of primate sensory neuron types is critical for understanding the cellular origin and heritability of chronic pain. However, molecular insights into the primate sensory neurons are missing. Here we classify non-human primate dorsal root ganglion sensory neurons based on their transcriptome and map human pain heritability to neuronal types. First, we identified cell correlates between two major datasets for mouse sensory neuron types. Machine learning exposes an overall cross-species conservation of somatosensory neurons between primate and mouse, although with differences at individual gene level, highlighting the importance of primate data for clinical translation. We map genomic loci associated with chronic pain in human onto primate sensory neuron types to identify the cellular origin of chronic pain. Genome-wide associations for chronic pain converge on two different neuronal types distributed between pain disorders that display different genetic susceptibilities, suggesting both unique and shared mechanisms between different pain conditions.
Project description:Distinct types of dorsal root ganglion sensory neurons may have unique contributions to chronic pain. Identification of primate sensory neuron types is critical for understanding the cellular origin and heritability of chronic pain. However, molecular insights into the primate sensory neurons are missing. Here we classify non-human primate dorsal root ganglion sensory neurons based on their transcriptome and map human pain heritability to neuronal types. First, we identified cell correlates between two major datasets for mouse sensory neuron types. Machine learning exposes an overall cross-species conservation of somatosensory neurons between primate and mouse, although with differences at individual gene level, highlighting the importance of primate data for clinical translation. We map genomic loci associated with chronic pain in human onto primate sensory neuron types to identify the cellular origin of chronic pain. Genome-wide associations for chronic pain converge on two different neuronal types distributed between pain disorders that display different genetic susceptibilities, suggesting both unique and shared mechanisms between different pain conditions.
Project description:Molecular characterization of the individual neuron types existing in the primate dorsal root ganglion and the relation to model organisms used for studying somatosensation and pain is critical for understanding the cellular origin of chronic pain and for translational aspects of biomedical research. However, molecular insights into the primate dorsal root ganglion are missing and a systematic comparison of strategies for somatosensation between the mouse and primates is lacking. Here we classify non-human primate sensory neurons based on their transcriptome and identify neuronal types with heritability to chronic pain. We identify nine neuronal types and use machine learning to expose an overall cross-species conserved strategy and shared taxonomy for nociception, although with differences at individual gene level, highlighting the importance of incorporating primate knowledge for the successful translation of discoveries in rodent model organisms. Genomic loci implicated in chronic pain were mapped onto specific primate sensory neuron types to identify the cellular origin of chronic pain. The common-variant genome-wide association results for chronic pain point to the same cells at the same pain sites and concentrate on two different neuronal types between pain disorders, suggesting that causative cell types and molecular mechanisms are different between different pain conditions.
Project description:Chronic neuropathic pain is widespread, but individual diagnostic biomarkers are unknown and primate specificity hampers rodent validation tests. Here, we report that microRNA (miR)-sequencing of blood leukocytes from 250 multi-centre pain patients revealed complex regional pain syndrome (CRPS)-related increases in the pain-related microRNA (miR)-21-5p and decreases in the cholinergic-targeted miR-335-5p. Both these miRs were similarly modified in dorsal root ganglia of nerve-injured mice, where long RNA-sequencing detected pain-associated elevation of neurogenesis and inflammation-related transcripts. Moreover, either genomic ablation or intrathecal antisense oligonucleotide neuro-suppression of miR-21a-5p, but not genetic debilitation of B7-H1 lymphocytes alleviated murine pain responses while reducing cellular pathways that are induced in patients’ leukocytes; and a cooperative leukocyte ‘signature’ of 12 miRs including miR-21a-5p and -335-5p predicted 96% of CRPS symptoms severity. Our findings implicate cholinergic-suppressible neuro-inflammation processes in chronic acute pain, suggest pathway-based cooperative validation tests and open unprecedented options for mechanistic studies of chronic pain disorders.
Project description:We used transcriptome-wide data to investigate the molecular pathophysiological mechanisms in peripheral blood immune cells at the transcriptome-wide level that underlie the transition of acute to chronic low back pain.
Project description:Single-nucleus RNA sequencing was used to profile transcriptional differences in mice in uninjured or neuropathic chronic pain conditions and in response to multiple sensory stimuli to identify cell subtype-specific changes in the transcriptome due to pain