Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuropathic pain is associated with changes in the electrophysiological and neurochemical properties of injured primary afferent neurons. A mRNA differential display study in rat L(4/5) dorsal root ganglia (DRGs) revealed upregulation of the calcium channel alpha2delta-1 subunit 2 weeks after partial sciatic nerve ligation (Seltzer model of neuropathic pain). The upregulated transcript appeared to represent previously unidentified sequence from the 3'-untranslated region of rat alpha2delta-1 mRNA. In situ hybridization using L(5) DRGs from sham operated rats showed that 73, 40 and 19% of small (<700 microm(2)), medium (700-1100 microm(2)) and large (>1100 microm(2)) neuronal profiles, respectively, expressed alpha2delta-1 mRNA. Two weeks following nerve injury there was a significant ipsilateral increase, both in the percentage of DRG neurons expressing alpha2delta-1 mRNA and in the intensity of the hybridization signal. Comparison of this ipsilateral expression with that in sham animals, revealed that for small, medium and large neurons, respectively, the proportion of neurons labelled increased by 1.2-, 1.8- and 2.7-fold, while the hybridization signal in alpha2delta-1-labelled neurons increased by 2.8-, 2.5- and 3.7-fold. The most intensely labelled neuronal profiles in ipsilateral, sham and contralateral DRGs, were generally those with small cross-sectional areas. The alpha2delta-1 auxiliary subunit is known to modulate calcium channel function in heterologous expression systems via its association with the pore-forming alpha1 calcium channel subunit. Therefore the increased levels of this subunit in the populations of primary afferents described may, via modulation of calcium-dependent processes such as neurotransmitter release and neuronal excitability, influence the processing of sensory information.
Brain Res Mol Brain Res 2001 Nov 01
PMID:Dorsal root ganglion neurons show increased expression of the calcium channel alpha2delta-1 subunit following partial sciatic nerve injury. 1168 71

Activation of cutaneous C-fibers by capsaicin or sciatic nerve transection increases the number of astrocytic gap junctions as well as the levels of connexin 43 in the dorsal horn on the stimulated side. Changes in connexin 37 mRNA expression following nerve injury have not been previously documented. We examined the role of gap junction protein connexin 37 in neuropathic hypersensitivity following peripheral nerve injury. Study results showed ipsilaterally increased connexin 37 mRNA levels proximally and distally in rat sciatic nerves after injury and behavioral thermal hyperalgesia at 7 and 14 days. Proximal and distal connexin 37 mRNA levels returned to baseline by 21 days. Sciatic nerve connexin 37 mRNA increases were proportional to the extent of thermal hyperalgesia, but skin, muscle, and lumbar spinal cord connexin 37 mRNA showed no significant changes. Neuropathic pain relief correlated with downregulation of connexin 37 mRNA. Results indicate that upregulation of connexin 37 mRNA following sciatic nerve injury correlates with subsequent thermal hyperalgesia, which suggests that gap junctions (connexin 37) are responsible for the hyperexcitability following peripheral nerve injury.
Brain Res Mol Brain Res 2002 Mar 28
PMID:Induction of connexin 37 expression in a rat model of neuropathic pain. 1197 4

Neuropathic pain is caused by nervous-system lesions. Early studies on the pathomechanisms of this abnormal pain state have focused on the directly injured fibers and neurons. Here, we present recently accumulating data about the contribution of the primary afferent neurons spared from direct injury to the pathomechanisms of neuropathic pain. The phenotypic changes in the spared neurons are similar to those in the neurons in peripheral inflammation models, as opposed to those in the directly injured neurons. Electrophysiological changes and behavioral data also favor the contribution of the spared neurons. These attractive targets of study will give us new approaches for understanding the abnormal pain.
Mol Neurobiol 2002 Aug
PMID:Contribution of the spared primary afferent neurons to the pathomechanisms of neuropathic pain. 1239 56

Neuropathic pain is a difficult clinical problem that is often refractory to medical management. Glial-derived neurotrophic factor (GDNF) administered intrathecally has been shown to prevent or reduce pain in an animal model of neuropathic pain, but cannot be delivered in the required doses to treat human pain. We have previously demonstrated that peripheral subcutaneous inoculation of a replication-incompetent herpes simplex virus (HSV)-based vector can be used to transduce neurons of the dorsal root ganglion. To examine whether HSV-mediated expression of GDNF could be used to ameliorate neuropathic pain, we constructed a replication-incompetent HSV vector expressing GDNF. Subcutaneous inoculation of the vector 1 week after spinal nerve ligation resulted in a continuous antiallodynic effect that was maintained for 3-4 weeks. Reinoculation of the vector reestablished the antiallodynic effect with a magnitude that was at least equivalent to the initial effect. Vector-mediated GDNF expression blocked the nonnoxious touch-induced increase in c-fos expression in dorsal horn characteristic of the painful state. Gene transfer to produce a trophic factor offers a novel approach to the treatment of neuropathic pain that may be appropriate for human therapy.
Mol Ther 2003 Sep
PMID:HSV-mediated gene transfer of the glial cell-derived neurotrophic factor provides an antiallodynic effect on neuropathic pain. 1294 9

Neuropathic pain after spinal cord injury (SCI) represents a difficult problem that is commonly refractory to conventional medical management. To determine if spinal release of gamma-amino butyric acid (GABA) could reduce below-level central neuropathic pain after SCI, we constructed a replication-incompetent herpes simplex virus (HSV)-based vector encoding one isoform of human glutamic acid decarboxylase (GAD67). Dorsal root ganglion (DRG) neurons transduced in vitro or in vivo by subcutaneous inoculation produced GAD and released GABA constitutively. T13 spinal cord hemisection resulted in central neuropathic pain manifested by mechanical allodynia and thermal hyperalgesia. Subcutaneous inoculation of the vector into both feet reduced both manifestations of below-level SCI pain; the vector-mediated effect was partially reversed by intrathecal bicuculline or phaclofen at doses that did not affect thresholds in normal or injured uninoculated animals. Vector-mediated GABA release attenuated the increase in spinal calcitonin gene-related peptide immunoreactivity caused by cord hemisection. These results suggest that HSV-mediated gene transfer to DRG could be used to treat below-level central neuropathic pain after incomplete SCI.
Mol Ther 2004 Jul
PMID:Peripherally delivered glutamic acid decarboxylase gene therapy for spinal cord injury pain. 1523 42

Neuropathic pain involves co-regulation of many genes and their translational products in both peripheral and central nervous system. We used proteomics approaches to investigate expressional changes in cytosolic protein levels in rat brainstem tissues following ligation of lumbar 5 and 6 (L5, L6) spinal nerves, which generates a model of peripheral neuropathic pain (NP). Proteins from brainstem tissue homogenates of NP and SHAM animals were fractionated by two-dimensional (2-DE) gel electrophoresis to produce a high-resolution map of the brainstem soluble proteins. Proteins showing altered expression levels between NP and SHAM were selected. Isolated proteins were in-gel trypsin-digested and the resulting peptides were analyzed by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry. Using the mass spectrometric data, we were able to identify 17 proteins of interest through searches of the Swiss-Prot and NCBi nonredundant protein sequence database. Several of the identified proteins, including fatty acid binding protein-brain (FABP-B), major histocompatibility complex (MHC) class 1, T-cell receptor (TCR) alpha chain, and interleukin-1 (IL-1), showed significantly higher levels in the NP rat brainstem. Proteomic analysis has identified several proteins with differential expression levels in NP as compared to SHAM. However, the function of the proteins identified is postulated; therefore, further experiments are required to determine the true role of each protein in NP.
Brain Res Mol Brain Res 2004 Sep 28
PMID:Proteomic identification of brainstem cytosolic proteins in a neuropathic pain model. 1536 94

Neuropathic pain developing after peripheral nerve injury is associated with altered neuronal and glial cell functions in the spinal cord. Activated glia produces algogenic mediators, exacerbating pain. Among the different intracellular pathways possibly involved in the modified glial function, the nuclear factor kappaB (NF-kappaB) system is of particular interest, as numerous genes encoding inflammation- and pain-related molecules are controlled by this transcription factor. NF-kappaB is a pleiotropic factor also involved in central nervous system homeostasy. To study its role in chronic pain, it is thus essential to inhibit the NF-kappaB pathway selectively in activated spinal glial cells. Here, we show that when restricted to spinal cord and targeted to glial cells, lentiviral vector-mediated delivery of NF-kappaB super- repressor IkappaBalpha resulted in an inhibition of the NF-kappaB pathway activated in the rat spinal cord after sciatic nerve injury (chronic constriction injury, CCI). Concomitantly, IkappaBalpha overproduction prevented the enhanced expression of interleukin-6 and of inducible nitric oxide synthase associated with chronic constriction injury and resulted in prolonged antihyperalgesic and antiallodynic effects. These data show that targeted blockade of NF-kappaB activity in spinal glia efficiently alleviates pain behavior in CCI rats, demonstrating the active participation of the glial NF-kappaB pathway in the development of neuropathic pain after peripheral nerve injury.
Mol Ther 2007 Apr
PMID:Lentiviral-mediated targeted NF-kappaB blockade in dorsal spinal cord glia attenuates sciatic nerve injury-induced neuropathic pain in the rat. 1729 2

Neuropathic pain occurs as a result of peripheral or central nervous system injury. Its pathophysiology involves mainly a central sensitization mechanism that may be correlated to many molecules acting in regions involved in pain processing, such as the spinal cord. It has been demonstrated that reactive oxygen species (ROS) and signaling molecules, such as the serine/threonine protein kinase Akt, are involved in neuropathic pain mechanisms. Thus, the aim of this study was to provide evidence of this relationship. Sciatic nerve transection (SNT) was used to induce neuropathic pain in rats. Western blot analysis of Akt and 4-hydroxy-2-nonenal (HNE)-Michael adducts, and measurement of hydrogen peroxide (H(2)O(2)) in the lumbosacral spinal cord were performed. The main findings were found seven days after SNT, when there was an increase in HNE-Michael adducts formation, total and p-Akt expression, and H(2)O(2) concentration. However, one and 15 days after SNT, H(2)O(2) concentration was raised in both sham (animals that were submitted to surgery without nerve injury) and SNT groups, showing the high sensibility of this ROS to nociceptive afferent stimuli, not only to neuropathic pain. p-Akt also increased in sham and SNT groups one day post injury, but at 3 and 7 days the increase occurred exclusively in SNT animals. Thus, there is crosstalk between intracellular signaling pathways and ROS, and these molecules can act as protective agents in acute pain situations or play a role in the development of chronic pain states.
Cell Mol Neurobiol 2008 Dec
PMID:Increase in reactive oxygen species and activation of Akt signaling pathway in neuropathic pain. 1837 70

Neuropathic pain may arise following peripheral nerve injury though the molecular mechanisms associated with this are unclear. We used proteomic profiling to examine changes in protein expression associated with the formation of hyper-excitable neuromas derived from rodent saphenous nerves. A two-dimensional difference gel electrophoresis (2D-DIGE) profiling strategy was employed to examine protein expression changes between developing neuromas and normal nerves in whole tissue lysates. We found around 200 proteins which displayed a >1.75-fold change in expression between neuroma and normal nerve and identified 55 of these proteins using mass spectrometry. We also used immunoblotting to examine the expression of low-abundance ion channels Nav1.3, Nav1.8 and calcium channel alpha2delta-1 subunit in this model, since they have previously been implicated in neuronal hyperexcitability associated with neuropathic pain. Finally, S35methionine in vitro labelling of neuroma and control samples was used to demonstrate local protein synthesis of neuron-specific genes. A number of cytoskeletal proteins, enzymes and proteins associated with oxidative stress were up-regulated in neuromas, whilst overall levels of voltage-gated ion channel proteins were unaffected. We conclude that altered mRNA levels reported in the somata of damaged DRG neurons do not necessarily reflect levels of altered proteins in hyper-excitable damaged nerve endings. An altered repertoire of protein expression, local protein synthesis and topological re-arrangements of ion channels may all play important roles in neuroma hyper-excitability.
Mol Pain 2008 Aug 12
PMID:Proteomic profiling of neuromas reveals alterations in protein composition and local protein synthesis in hyper-excitable nerves. 1870 27

Neuropathic pain is a debilitating pain condition that occurs after nerve damage. Such pain is considered to be a reflection of the aberrant excitability of dorsal horn neurons. Emerging lines of evidence indicate that spinal microglia play a crucial role in neuronal excitability and the pathogenesis of neuropathic pain, but the mechanisms underlying neuron-microglia communications in the dorsal horn remain to be fully elucidated. A recent study has demonstrated that platelet-derived growth factor (PDGF) expressed in dorsal horn neurons contributes to neuropathic pain after nerve injury, yet how PDGF produces pain hypersensitivity remains unknown. Here we report an involvement of spinal microglia in PDGF-induced tactile allodynia. A single intrathecal delivery of PDGF B-chain homodimer (PDGF-BB) to naive rats produced a robust and long-lasting decrease in paw withdrawal threshold in a dose-dependent manner. Following PDGF administration, the immunofluorescence for phosphorylated PDGF beta-receptor (p-PDGFR beta), an activated form, was markedly increased in the spinal dorsal horn. Interestingly, almost all p-PDGFR beta-positive cells were double-labeled with an antibody for the microglia marker OX-42, but not with antibodies for other markers of neurons, astrocytes and oligodendrocytes. PDGF-stimulated microglia in vivo transformed into a modest activated state in terms of their cell number and morphology. Furthermore, PDGF-BB-induced tactile allodynia was prevented by a daily intrathecal administration of minocycline, which is known to inhibit microglia activation. Moreover, in rats with an injury to the fifth lumbar spinal nerve (an animal model of neuropathic pain), the immunofluorescence for p-PDGFR beta was markedly enhanced exclusively in microglia in the ipsilateral dorsal horn. Together, our findings suggest that spinal microglia critically contribute to PDGF-induced tactile allodynia, and it is also assumed that microglial PDGF signaling may have a role in the pathogenesis of neuropathic pain.
Mol Pain 2009 May 11
PMID:Intrathecal delivery of PDGF produces tactile allodynia through its receptors in spinal microglia. 1942 64


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