Pain Management Commons^™

Nerve Injury Inhibits Oprd1 And Cnr1 Transcription Through Rest In Primary Sensory Neurons, Ashok Subedi, Asieh Etemad, Aadhya Tiwari, Yuying Huang, Biji Chatterjee, Samantha M Mcleod, Yungang Lu, Diangelo Gonzalez, Krishna Ghosh, Mario Sirito, Sanjay K Singh, Elisa Ruiz, Sandra L Grimm, Cristian Coarfa, Hui-Lin Pan, Sadhan Majumder

Faculty, Staff and Students Publications

The transcription repressor REST in the dorsal root ganglion (DRG) is upregulated by peripheral nerve injury and promotes the development of chronic pain. However, the genes targeted by REST in neuropathic pain development remain unclear. The expression levels of four opioid receptor genes (Oprm1, Oprd1, Oprl1 and Oprk1) and the cannabinoid CB1 receptor (Cnr1) gene in the DRG regulate nociception. In this study, we determined the role of REST in controlling their expression in the DRG induced by spared nerve injury (SNI). SNI induced chronic pain hypersensitivity in wild-type mice and was accompanied by increased levels of Rest transcript and …

Readiness Of Nociceptor Cell Bodies To Generate Spontaneous Activity Results From Background Activity Of Diverse Ion Channels And High Input Resistance, Jinbin Tian, Alexis G Bavencoffe, Michael X Zhu, Edgar T Walters

Faculty, Staff and Student Publications

Nociceptor cell bodies generate "spontaneous" discharge that can promote ongoing pain in persistent pain conditions. Little is known about the underlying mechanisms. Recordings from nociceptor cell bodies (somata) dissociated from rodent and human dorsal root ganglia have shown that previous pain in vivo is associated with low-frequency discharge controlled by irregular depolarizing spontaneous fluctuations of membrane potential (DSFs), likely produced by transient inward currents across the somal input resistance. Using mouse nociceptors, we show that DSFs are associated with high somal input resistance over a wide range of membrane potentials, including depolarized levels where DSFs approach action potential (AP) threshold. …

Pain Management By Chemogenetic Control Of Sensory Neurons, Yize Li, Xin Ge, Ru-Rong Ji

Faculty, Staff and Student Publications

In this study, Perez-Sanchez et al.1 developed a chemogenetic method aimed at alleviating pain in mouse models while dampening excitability in human sensory neurons. This analgesic effect was attained through the introduction of human α7 nicotinic acetylcholine receptor and glycine receptor pore domain via virus-mediated expression in sensory neurons, forming a chloride channel. The activation of this channel was made possible by specific agonists. This study highlights the potential for treating clinical pain by gene therapy.

Early Resveratrol Treatment Mitigates Joint Degeneration And Dampens Pain In A Mouse Model Of Pseudoachondroplasia (Psach), Jacqueline T Hecht, Alka C Veerisetty, Debabrata Patra, Mohammad G Hossain, Frankie Chiu, Claire Mobed, Francis H Gannon, Karen L Posey

Faculty, Staff and Student Publications

Pseudoachondroplasia (PSACH), a severe dwarfing condition associated with early-onset joint degeneration and lifelong joint pain, is caused by mutations in cartilage oligomeric matrix protein (COMP). The mechanisms underlying the mutant-COMP pathology have been defined using the MT-COMP mouse model of PSACH that has the common D469del mutation. Mutant-COMP protein does not fold properly, and it is retained in the rough endoplasmic reticulum (rER) of chondrocytes rather than being exported to the extracellular matrix (ECM), driving ER stress that stimulates oxidative stress and inflammation, driving a self-perpetuating cycle. CHOP (ER stress signaling protein) and TNFα inflammation drive high levels of mTORC1 …

Tiam1 Coordinates Synaptic Structural And Functional Plasticity Underpinning The Pathophysiology Of Neuropathic Pain, Lingyong Li, Qin Ru, Yungang Lu, Xing Fang, Guanxing Chen, Ali Bin Saifullah, Changqun Yao, Kimberley F Tolias

Faculty, Staff and Students Publications

Neuropathic pain is a common, debilitating chronic pain condition caused by damage or a disease affecting the somatosensory nervous system. Understanding the pathophysiological mechanisms underlying neuropathic pain is critical for developing new therapeutic strategies to treat chronic pain effectively. Tiam1 is a Rac1 guanine nucleotide exchange factor (GEF) that promotes dendritic and synaptic growth during hippocampal development by inducing actin cytoskeletal remodeling. Here, using multiple neuropathic pain animal models, we show that Tiam1 coordinates synaptic structural and functional plasticity in the spinal dorsal horn via actin cytoskeleton reorganization and synaptic NMDAR stabilization and that these actions are essential for the …

Aibp Regulates Trpv1 Activation In Chemotherapy-Induced Peripheral Neuropathy By Controlling Lipid Raft Dynamics And Proximity To Tlr4 In Dorsal Root Ganglion Neurons, Juliana M Navia-Pelaez, Julia Borges Paes Lemes, Leonardo Gonzalez, Lauriane Delay, Luciano Dos Santos Aggum Capettini, Jenny W Lu, Gilson Gonçalves Dos Santos, Ann M Gregus, Patrick M Dougherty, Tony L Yaksh, Yury I Miller

Faculty, Staff and Student Publications

Nociceptive afferent signaling evoked by inflammation and nerve injury is mediated by the opening of ligand-gated and voltage-gated receptors or channels localized to cholesterol-rich lipid raft membrane domains. Dorsal root ganglion (DRG) nociceptors express high levels of toll-like receptor 4 (TLR4), which also localize to lipid rafts. Genetic deletion or pharmacologic blocking of TLR4 diminishes pain associated with chemotherapy-induced peripheral neuropathy (CIPN). In DRGs of mice with paclitaxel-induced CIPN, we analyzed DRG neuronal lipid rafts, expression of TLR4, activation of transient receptor potential cation channel subfamily V member 1 (TRPV1), and TLR4-TRPV1 interaction. Using proximity ligation assay, flow cytometry, and …

Tiam1-Mediated Synaptic Plasticity Underlies Comorbid Depression-Like And Ketamine Antidepressant-Like Actions In Chronic Pain, Qin Ru, Yungang Lu, Ali Bin Saifullah, Francisco A Blanco, Changqun Yao, Juan P Cata, De-Pei Li, Kimberley F Tolias, Lingyong Li

Faculty, Staff and Students Publications

Chronic pain often leads to depression, increasing patient suffering and worsening prognosis. While hyperactivity of the anterior cingulate cortex (ACC) appears to be critically involved, the molecular mechanisms underlying comorbid depressive symptoms in chronic pain remain elusive. T cell lymphoma invasion and metastasis 1 (Tiam1) is a Rac1 guanine nucleotide exchange factor (GEF) that promotes dendrite, spine, and synapse development during brain development. Here, we show that Tiam1 orchestrates synaptic structural and functional plasticity in ACC neurons via actin cytoskeleton reorganization and synaptic N-methyl-d-aspartate receptor (NMDAR) stabilization. This Tiam1-coordinated synaptic plasticity underpins ACC hyperactivity and drives chronic pain-induced depressive-like behaviors. …

Hdac2 In Primary Sensory Neurons Constitutively Restrains Chronic Pain By Repressing Α2Δ-1 Expression And Associated Nmda Receptor Activity, Jixiang Zhang, Shao-Rui Chen, Meng-Hua Zhou, Daozhong Jin, Hong Chen, Li Wang, Ronald A Depinho, Hui-Lin Pan

Faculty, Staff and Student Publications

α2δ-1 (encoded by the Cacna2d1 gene) is a newly discovered NMDA receptor-interacting protein and is the therapeutic target of gabapentinoids (e.g., gabapentin and pregabalin) frequently used for treating patients with neuropathic pain. Nerve injury causes sustained α2δ-1 upregulation in the dorsal root ganglion (DRG), which promotes NMDA receptor synaptic trafficking and activation in the spinal dorsal horn, a hallmark of chronic neuropathic pain. However, little is known about how nerve injury initiates and maintains the high expression level of α2δ-1 to sustain chronic pain. Here, we show that nerve injury caused histone hyperacetylation and diminished enrichment of histone deacetylase-2 (HDAC2), …

Preconditioning By Voluntary Wheel Running Attenuates Later Neuropathic Pain Via Nuclear Factor E2-Related Factor 2 Antioxidant Signaling In Rats, Suzanne M Green-Fulgham, Michael E Harland, Jayson B Ball, Jiahe Li, Michael J Lacagnina, Heather D'Angelo, Renee A Dreher, Kendal F Willcox, Sabina A Lorca, Andrew J Kwilasz, Steven F Maier, Linda R Watkins, Peter M Grace

Faculty, Staff and Student Publications

Animal and human studies have shown that exercise prior to nerve injury prevents later chronic pain, but the mechanisms of such preconditioning remain elusive. Given that exercise acutely increases the formation of free radicals, triggering antioxidant compensation, we hypothesized that voluntary running preconditioning would attenuate neuropathic pain by supporting redox homeostasis after sciatic nerve injury in male and female rats. We show that 6 weeks of voluntary wheel running suppresses neuropathic pain development induced by chronic constriction injury across both sexes. This attenuation was associated with reduced nitrotyrosine immunoreactivity-a marker for peroxynitrite-at the sciatic nerve injury site. Our data suggest …

In Vivo Measurement Of Intradiscal Pressure Changes Related To Thrust And Non-Thrust Spinal Manipulation In An Animal Model: A Pilot Study, William R Reed, Michael A K Liebschner, Carla R Lima, Harshvardhan Singh, Christopher P Hurt, Daniel F Martins, James M Cox, Maruti R Gudavalli

Faculty, Staff and Students Publications

BACKGROUND: The intervertebral disc is a known back pain generator and is frequently the focus of spinal manipulative therapy evaluation and treatment. The majority of our current knowledge regarding intradiscal pressure (IDP) changes related to spinal manual therapy involves cadaveric studies with their inherent limitations. Additional in vivo animal models are needed to investigate intervertebral disc physiological and molecular mechanisms related to spinal manipulation and spinal mobilization treatment for low back disorders.

METHODS: Miniature pressure catheters (Millar SPR-1000) were inserted into either the L4-L5 or L5-L6 intervertebral disc of 3 deeply anesthetized adult cats (Oct 2012-May 2013). Changes in IDP …

Role Of Micro-Rna For Pain After Surgery: Narrative Review Of Animal And Human Studies, Juan P Cata, Aysegul Gorur, Xiaoyi Yuan, Nathaniel K Berg, Anil K Sood, Holger K Eltzschig

Faculty, Staff and Student Publications

One of the most prevalent symptoms after major surgery is pain. When postoperative pain treatment is unsatisfactory, it can lead to poor surgical recovery, decreased quality of life, and increased health care costs. Current analgesics, single or in combination, have limited efficacy due to low potency, limited duration of action, toxicities, and risk of addiction. The lack of nonaddictive strong analgesics along with the over prescription of opioids has led to an opioid epidemic in the United States. Therefore, there is an urgent need for the development of newer analgesics. Microribonucleic acids (miRNAs) are small noncoding RNA molecules that modulate …

Chronic Spontaneous Activity Generated In The Somata Of Primary Nociceptors Is Associated With Pain-Related Behavior After Spinal Cord Injury, Supinder S Bedi, Qing Yang, Robyn J Crook, Junhui Du, Zizhen Wu, Harvey M Fishman, Raymond J Grill, Susan M Carlton, Edgar T Walters

Faculty, Staff and Student Publications

Mechanisms underlying chronic pain that develops after spinal cord injury (SCI) are incompletely understood. Most research on SCI pain mechanisms has focused on neuronal alterations within pain pathways at spinal and supraspinal levels associated with inflammation and glial activation. These events might also impact central processes of primary sensory neurons, triggering in nociceptors a hyperexcitable state and spontaneous activity (SA) that drive behavioral hypersensitivity and pain. SCI can sensitize peripheral fibers of nociceptors and promote peripheral SA, but whether these effects are driven by extrinsic alterations in surrounding tissue or are intrinsic to the nociceptor, and whether similar SA occurs …

Molluscan Memory Of Injury: Evolutionary Insights Into Chronic Pain And Neurological Disorders, Edgar T Walters, Leonid L Moroz

Faculty, Staff and Student Publications

Molluscan preparations have yielded seminal discoveries in neuroscience, but the experimental advantages of this group have not, until now, been complemented by adequate molecular or genomic information for comparisons to genetically defined model organisms in other phyla. The recent sequencing of the transcriptome and genome of Aplysia californica, however, will enable extensive comparative studies at the molecular level. Among other benefits, this will bring the power of individually identifiable and manipulable neurons to bear upon questions of cellular function for evolutionarily conserved genes associated with clinically important neural dysfunction. Because of the slower rate of gene evolution in this molluscan …