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Kim SY, Park JE, Lee HJ, Sim DY, Ahn CH, Park SY, Shim BS, Kim B, Lee DY, Kim SH. Astragalus membranaceus Extract Induces Apoptosis via Generation of Reactive Oxygen Species and Inhibition of Heat Shock Protein 27 and Androgen Receptor in Prostate Cancers. Int J Mol Sci 2024; 25:2799. [PMID: 38474045 DOI: 10.3390/ijms25052799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/31/2024] [Accepted: 02/07/2024] [Indexed: 03/14/2024] Open
Abstract
Although Astragalus membranaceus is known to have anti-inflammatory, anti-obesity, and anti-oxidant properties, the underlying apoptotic mechanism of Astragalus membranaceus extract has never been elucidated in prostate cancer. In this paper, the apoptotic mechanism of a water extract from the dried root of Astragalus membranaceus (WAM) was investigated in prostate cancer cells in association with heat shock protein 27 (HSP27)/androgen receptor (AR) signaling. WAM increased cytotoxicity and the sub-G1 population, cleaved poly (ADP-ribose) polymerase (PARP) and cysteine aspartyl-specific protease 3 (caspase 3), and attenuated the expression of B-cell lymphoma 2 (Bcl-2) in LNCaP cells after 24 h of exposure. Consistently, WAM significantly increased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive LNCaP cells. WAM decreased the phosphorylation of HSP27 on Ser82 and inhibited the expression of the AR and prostate-specific antigen (PSA), along with reducing the nuclear translocation of p-HSP27 and the AR via the disturbed binding of p-HSP27 with the AR in LNCaP cells. WAM consistently inhibited the expression of the AR and PSA in dihydrotestosterone (DHT)-treated LNCaP cells. WAM also suppressed AR stability, both in the presence and absence of cycloheximide, in LNCaP cells. Taken together, these findings provide evidence that WAM induces apoptosis via the inhibition of HSP27/AR signaling in prostate cancer cells and is a potent anticancer candidate for prostate cancer treatment.
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Affiliation(s)
- Seok-Young Kim
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Ji Eon Park
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hyo-Jung Lee
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Deok Yong Sim
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Chi-Hoon Ahn
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Su-Yeon Park
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Bum-Sang Shim
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Bonglee Kim
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Dae Young Lee
- Department of Herbal Crop Research, National Institute of Horticultural and Herbal Science, Rural Development Administration, Eumseong 27709, Republic of Korea
| | - Sung-Hoon Kim
- College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
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Cao F, Wang X, Ye Q, Yan F, Lu W, Xie J, Bi B, Wang X. Identifying circRNA-miRNA-mRNA Regulatory Networks in Chemotherapy-Induced Peripheral Neuropathy. Curr Issues Mol Biol 2023; 45:6804-6822. [PMID: 37623249 PMCID: PMC10453290 DOI: 10.3390/cimb45080430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/13/2023] [Accepted: 08/15/2023] [Indexed: 08/26/2023] Open
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent and severe side effect of first-line chemotherapeutic agents. The association between circular RNAs (circRNAs) and CIPN remains unclear. In this study, CIPN models were constructed with Taxol, while 134 differentially expressed circRNAs, 353 differentially expressed long non-coding RNAs, and 86 differentially expressed messenger RNAs (mRNAs) were identified utilizing RNA sequencing. CircRNA-targeted microRNAs (miRNAs) were predicted using miRanda, and miRNA-targeted mRNAs were predicted using TargetScan and miRDB. The intersection of sequencing and mRNA prediction results was selected to establish the circRNA-miRNA-mRNA networks, which include 15 circRNAs, 18 miRNAs, and 11 mRNAs. Functional enrichment pathway analyses and immune infiltration analyses revealed that differentially expressed mRNAs were enriched in the immune system, especially in T cells, monocytes, and macrophages. Cdh1, Satb2, Fas, P2ry2, and Zfhx2 were further identified as hub genes and validated by RT-qPCR, correlating with macrophages, plasmacytoid dendritic cells, and central memory CD4 T cells in CIPN. Additionally, we predicted the associated diseases, 36 potential transcription factors (TFs), and 30 putative drugs for hub genes using the DisGeNET, TRRUST, and DGIdb databases, respectively. Our results indicated the crucial role of circRNAs, and the immune microenvironment played in CIPN, providing novel insights for further research.
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Affiliation(s)
- Fei Cao
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China; (F.C.); (X.W.); (Q.Y.); (F.Y.); (W.L.); (J.X.)
| | - Xintong Wang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China; (F.C.); (X.W.); (Q.Y.); (F.Y.); (W.L.); (J.X.)
| | - Qingqing Ye
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China; (F.C.); (X.W.); (Q.Y.); (F.Y.); (W.L.); (J.X.)
| | - Fang Yan
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China; (F.C.); (X.W.); (Q.Y.); (F.Y.); (W.L.); (J.X.)
| | - Weicheng Lu
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China; (F.C.); (X.W.); (Q.Y.); (F.Y.); (W.L.); (J.X.)
| | - Jingdun Xie
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China; (F.C.); (X.W.); (Q.Y.); (F.Y.); (W.L.); (J.X.)
| | - Bingtian Bi
- Department of Clinical Trial Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Xudong Wang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China; (F.C.); (X.W.); (Q.Y.); (F.Y.); (W.L.); (J.X.)
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Chase R, de la Peña JB, Smith PR, Lawson J, Lou TF, Stanowick AD, Black BJ, Campbell ZT. Global analyses of mRNA expression in human sensory neurons reveal eIF5A as a conserved target for inflammatory pain. FASEB J 2022; 36:e22422. [PMID: 35747924 DOI: 10.1096/fj.202101933rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 05/28/2022] [Accepted: 06/08/2022] [Indexed: 11/11/2022]
Abstract
Nociceptors are a type of sensory neuron that are integral to most forms of pain. Targeted disruption of nociceptor sensitization affords unique opportunities to prevent pain. An emerging model for nociceptors are sensory neurons derived from human stem cells. Here, we subjected five groups to high-throughput sequencing: human induced pluripotent stem cells (hiPSCs) prior to differentiation, mature hiPSC-derived sensory neurons, mature co-cultures containing hiPSC-derived astrocytes and sensory neurons, mouse dorsal root ganglion (DRG) tissues, and mouse DRG cultures. Co-culture of nociceptors and astrocytes promotes expression of transcripts enriched in DRG tissues. Comparisons of the hiPSC models to tissue samples reveal that many key transcripts linked to pain are present. Markers indicative of a range of neuronal subtypes present in the DRG were detected in mature hiPSCs. Intriguingly, translation factors were maintained at consistently high expression levels across species and culture systems. As a proof of concept for the utility of this resource, we validated expression of eukaryotic initiation factor 5A (eIF5A) in DRG tissues and hiPSC samples. eIF5A is subject to a unique posttranslational hypusine modification required for its activity. Inhibition of hypusine biosynthesis prevented hyperalgesic priming by inflammatory mediators in vivo and diminished hiPSC activity in vitro. Collectively, our results illuminate the transcriptomes of hiPSC sensory neuron models. We provide a demonstration for this resource through our investigation of eIF5A. Our findings reveal hypusine as a potential target for inflammation associated pain in males.
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Affiliation(s)
- Rebecca Chase
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - June Bryan de la Peña
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Patrick R Smith
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Jennifer Lawson
- Department of Biomedical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Tzu-Fang Lou
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Alexander D Stanowick
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Bryan J Black
- Department of Biomedical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Zachary T Campbell
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA.,Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, Texas, USA
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Kays J, Zhang YH, Khorodova A, Strichartz G, Nicol GD. Peripheral Synthesis of an Atypical Protein Kinase C Mediates the Enhancement of Excitability and the Development of Mechanical Hyperalgesia Produced by Nerve Growth Factor. Neuroscience 2017; 371:420-432. [PMID: 29288797 DOI: 10.1016/j.neuroscience.2017.12.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 12/18/2017] [Accepted: 12/20/2017] [Indexed: 12/26/2022]
Abstract
Nerve growth factor (NGF) plays a key role in the initiation as well as the prolonged heightened pain sensitivity of the inflammatory response. Previously, we showed that NGF rapidly augmented both the excitability of isolated rat sensory neurons and the mechanical sensitivity of the rat's hind paw. The increase in excitability and sensitivity was blocked by the myristoylated pseudosubstrate inhibitor of atypical PKCs (mPSI), suggesting that an atypical PKC may play a key regulatory role in generating this heightened sensitivity. Our findings raised the question as to whether NGF directs changes in translational control, as suggested for long-lasting long-term potentiation (LTP), or whether NGF leads to the activation of an atypical PKC by other mechanisms. The current studies demonstrate that enhanced action potential (AP) firing produced by NGF was blocked by inhibitors of translation, but not transcription. In parallel, in vitro studies showed that NGF elevated the protein levels of PKMζ, which was also prevented by inhibitors of translation. Intraplantar injection of NGF in the rat hind paw produced a rapid and maintained increase in mechanical sensitivity whose onset was delayed by translation inhibitors. Established NGF-induced hypersensitivity could be transiently reversed by injection of rapamycin or mPSI. These results suggest that NGF produces a rapid increase in the synthesis of PKMζ protein in the paw that augments neuronal sensitivity and that the ongoing translational expression of PKMζ plays a critical role in generating as well as maintaining the heightened sensitivity produced by NGF.
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Affiliation(s)
- Joanne Kays
- Department of Pharmacology and Toxicology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - Yi Hong Zhang
- Department of Pharmacology and Toxicology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - Alla Khorodova
- Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02135-6110, United States
| | - Gary Strichartz
- Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02135-6110, United States
| | - Grant D Nicol
- Department of Pharmacology and Toxicology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States.
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Guo Y, Yao FR, Cao DY, Li L, Wang HS, Xie W, Zhao Y. The major histocompatibility complex genes impact pain response in DA and DA.1U rats. Physiol Behav 2015; 147:30-7. [PMID: 25861730 DOI: 10.1016/j.physbeh.2015.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 03/13/2015] [Accepted: 04/04/2015] [Indexed: 12/29/2022]
Abstract
Our recent studies have shown that the difference in basal pain sensitivity to mechanical and thermal stimulation between Dark-Agouti (DA) rats and a novel congenic DA.1U rats is major histocompatibility complex (MHC) genes dependent. In the present study, we further used DA and DA.1U rats to investigate the role of MHC genes in formalin-induced pain model by behavioral, electrophysiological and immunohistochemical methods. Behavioral results showed biphasic nociceptive behaviors increased significantly following the intraplantar injection of formalin in the hindpaw of DA and DA.1U rats. The main nociceptive behaviors were lifting and licking, especially in DA rats (P<0.001 and P<0.01). The composite pain scores (CPS) in DA rats were significantly higher than those in DA.1U rats in both phases of the formalin test (P<0.01). Electrophysiological results also showed the biphasic increase in discharge rates of C and Aδ fibers of L5 dorsal root in the two strains, and the net change of the discharge rate of DA rats was significantly higher than that of DA.1U rats (P<0.05). The mechanical thresholds decreased after formalin injection in both strains (P<0.01), and the net change in the mechanical threshold in DA was greater than that in DA.1U rats (P<0.05). The expression of RT1-B, representation of MHC class II molecule, in laminae I-II of L4/5 spinal cord in DA rats was significantly higher than that in DA.1U rats in the respective experimental group (P<0.05). These results suggested that both DA and DA.1U rats exhibited nociceptive responses in formalin-induced pain model and DA rats were more sensitive to noxious chemical stimulus than DA.1U rats, indicating that MHC genes might contribute to the difference in pain sensitivity.
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Affiliation(s)
- Yuan Guo
- Department of Physiology and Pathophysiology, School of Basal Medical Science, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, PR China
| | - Fan-Rong Yao
- Department of Pharmacology and Toxicology in the Brody School of Medicine at East Carolina University, Greenville, NC, USA
| | - Dong-Yuan Cao
- Research Center, Stomatological Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710004, PR China; Department of Neural and Pain Sciences, University of Maryland Dental School, 650 West, Baltimore Street, Baltimore, MD 21201, USA
| | - Li Li
- Department of Physiology and Pathophysiology, School of Basal Medical Science, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, PR China
| | - Hui-Sheng Wang
- Department of Physiology and Pathophysiology, School of Basal Medical Science, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, PR China
| | - Wen Xie
- Department of Physiology and Pathophysiology, School of Basal Medical Science, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, PR China
| | - Yan Zhao
- Department of Physiology and Pathophysiology, School of Basal Medical Science, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, PR China.
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Pain and learning in a spinal system: contradictory outcomes from common origins. ACTA ACUST UNITED AC 2009; 61:124-43. [PMID: 19481111 DOI: 10.1016/j.brainresrev.2009.05.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 03/18/2009] [Accepted: 05/19/2009] [Indexed: 11/21/2022]
Abstract
The long-standing belief that the spinal cord serves merely as a conduit for information traveling to and from the brain is changing. Over the past decade, research has shown that the spinal cord is sensitive to response-outcome contingencies, demonstrating that spinal circuits have the capacity to modify behavior in response to differential environmental cues. If spinally transected rats are administered shock contingent on leg extension (controllable shock), they will maintain a flexion response that minimizes shock exposure. If, however, this contingency is broken, and shock is administered irrespective of limb position (uncontrollable shock), subjects cannot acquire the same flexion response. Interestingly, each of these treatments has a lasting effect on behavior; controllable shock enables future learning, while uncontrollable shock produces a long-lasting learning deficit. Here we suggest that the mechanisms underlying learning and the deficit may have evolved from machinery responsible for the spinal processing of noxious information. Experiments have shown that learning and the deficit require receptors and signaling cascades shown to be involved in central sensitization, including activation of NMDA and neurokinin receptors, as well as CaMKII. Further supporting this link between pain and learning, research has also shown that uncontrollable stimulation results in allodynia. Moreover, systemic inflammation and neonatal hindpaw injury each facilitate pain responding and undermine the ability of the spinal cord to support learning. These results suggest that the plasticity associated with learning and pain must be placed in a balance in order for adaptive outcomes to be observed.
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Decreased nociceptive sensitization in mice lacking the fragile X mental retardation protein: role of mGluR1/5 and mTOR. J Neurosci 2008; 27:13958-67. [PMID: 18094233 DOI: 10.1523/jneurosci.4383-07.2007] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Fragile X mental retardation is caused by silencing of the gene (FMR1) that encodes the RNA-binding protein (FMRP) that influences translation in neurons. A prominent feature of the human disorder is self-injurious behavior, suggesting an abnormality in pain processing. Moreover, FMRP regulates group I metabotropic glutamate receptor (mGluR1/5)-dependent plasticity, which is known to contribute to nociceptive sensitization. We demonstrate here, using the Fmr1 knock-out (KO) mouse, that FMRP plays an important role in pain processing because Fmr1 KO mice showed (1) decreased (approximately 50%) responses to ongoing nociception (phase 2, formalin test), (2) a 3 week delay in the development of peripheral nerve injury-induced allodynia, and (3) a near absence of wind-up responses in ascending sensory fibers after repetitive C-fiber stimulation. We provide evidence that the behavioral deficits are related to a mGluR1/5- and mammalian target of rapamycin (mTOR)-mediated mechanism because (1) spinal mGluR5 antagonism failed to inhibit the second phase of the formalin test, and we observed a marked reduction in nociceptive response to an intrathecal injection of an mGluR1/5 agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) in Fmr1 KO mice; (2) peripheral DHPG injection had no effect in KO mice yet evoked thermal hyperalgesia in wild types; and (3) the mTOR inhibitor rapamycin inhibited formalin- and DHPG-induced nociception in wild-type but not Fmr1 KO mice. These experiments show that translation regulation via FMRP and mTOR is an important feature of nociceptive plasticity. These observations also support the hypothesis that the persistence of self-injurious behavior observed in fragile X mental retardation patients could be related to deficits in nociceptive sensitization.
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Grau JW, Crown ED, Ferguson AR, Washburn SN, Hook MA, Miranda RC. Instrumental learning within the spinal cord: underlying mechanisms and implications for recovery after injury. ACTA ACUST UNITED AC 2007; 5:191-239. [PMID: 17099112 DOI: 10.1177/1534582306289738] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Using spinally transected rats, research has shown that neurons within the L4-S2 spinal cord are sensitive to response-outcome (instrumental) relations. This learning depends on a form of N-methyl-D-aspartate (NMDA)-mediated plasticity. Instrumental training enables subsequent learning, and this effect has been linked to the expression of brain-derived neurotrophic factor. Rats given uncontrollable stimulation later exhibit impaired instrumental learning, and this deficit lasts up to 48 hr. The induction of the deficit can be blocked by prior training with controllable shock, the concurrent presentation of a tonic stimulus that induces antinociception, or pretreatment with an NMDA or gamma-aminobutyric acid-A antagonist. The expression of the deficit depends on a kappa opioid. Uncontrollable stimulation enhances mechanical reactivity (allodynia), and treatments that induce allodynia (e.g., inflammation) inhibit learning. In intact animals, descending serotonergic neurons exert a protective effect that blocks the adverse consequences of uncontrollable stimulation. Uncontrollable, but not controllable, stimulation impairs the recovery of function after a contusion injury.
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Affiliation(s)
- James W Grau
- Department of Psychology, Texas A&M University, College Station, TX 77843-4235, USA.
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Yang HW, Zhou LJ, Hu NW, Xin WJ, Liu XG. Activation of spinal d1/d5 receptors induces late-phase LTP of C-fiber-evoked field potentials in rat spinal dorsal horn. J Neurophysiol 2005; 94:961-7. [PMID: 15829590 DOI: 10.1152/jn.01324.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Long-term potentiation (LTP) of C-fiber-evoked field potentials in spinal dorsal horn may be relevant to pathological pain. Our previous work has shown that the late phase of the spinal LTP is protein synthesis-dependent. Considerable evidence has accumulated that dopamine D1/D5 receptors are important for late-phase LTP in hippocampus. In this study, the role of D1/D5 receptors in LTP of C-fiber-evoked field potentials in spinal dorsal horn was evaluated in urethan-anesthetized Sprague-Dawley rats. We found the following. 1) Spinal application of SKF 38393, a D1/D5 receptor agonist, induced a slowly developed LTP of C-fiber-evoked field potentials, lasting for >10 h, and the effect was blocked by the D1/D5 antagonist SCH 23390, whereas a D2 receptor agonist (quinpirole) induced depression of C-fiber responses, lasting for 2 h. 2) The potentiation produced by D1/D5 receptor agonist occluded the late phase but not the early phase of the spinal LTP produced by tetanic stimulation. 3) SCH 23390 selectively depressed the late-phase LTP, when applied 40 min before tetanic stimulation. 4) The D1/D5 agonist-induced potentiation is blocked by the protein synthesis inhibitor anisomycin. 5) Activation of protein kinase A by spinal application of 8-Br-cAMP also induced spinal LTP, and the action occluded the potentiation induced by the D1/D5 receptor agonist. These results suggest that the spinal D1/D5 receptors participate in the protein synthesis-dependent late-phase LTP of C-fiber-evoked field potentials in spinal dorsal horn through the cAMP signaling pathway.
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Affiliation(s)
- Hong-Wei Yang
- Department of Physiology, Zhongshan Medical School of Sun Yat-sen University, Guangzhou, Peoples Republic of China
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Chan CF, Sun WZ, Lin JK, Lin-Shiau SY. Activation of transcription factors of nuclear factor kappa B, activator protein-1 and octamer factors in hyperalgesia. Eur J Pharmacol 2000; 402:61-8. [PMID: 10940358 DOI: 10.1016/s0014-2999(00)00431-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Involvement of c-fos and neuronal nitric oxide synthase (nNOS) in the hyperalgesia induced by complete Freund adjuvant (CFA) has been reported. In this paper, we attempted to investigate whether the transcription factors regulating the gene expression of c-fos and nNOS, including activator protein-1 (AP-1), nuclear factor kappa B (NF-kappa B), and octamer factors (Oct), are activated by CFA during the development of hyperalgesia. The electrophoretic mobility shift assay (EMSA) was used to determine whether there were changes in the transcription factors in the lumbar spinal cord of adult rats following subcutaneous injection of CFA in one hindpaw of the rats. Maximum binding of AP-1, NF-kappa B and Oct was found at 0.5, 1 and 2 h after CFA injection, respectively. These findings suggest that the activation of these transcription factors is pivotal for the expression of c-Fos and nNOS proteins, which reached a peak at 3 and 48 h after CFA injection, respectively. The behavioral testing of hyperalgesia demonstrated that CFA reduced the thresholds for mechanical and thermal algesia, reaching a minimum at 6 h. The thresholds had only partially recovered after 96 h. Based on these findings, we conclude that AP-1, NF-kappa B and Oct are crucial for the expression of c-Fos proteins at an early stage (at 3 h) and for the expression of nNOS at a late stage of hyperalgesia (48 h post-injection) induced by CFA.
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Affiliation(s)
- C F Chan
- Institute of Toxicology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei 10018, Taiwan
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Liu XG, Sandkühler J. Activation of spinal N-methyl-D-aspartate or neurokinin receptors induces long-term potentiation of spinal C-fibre-evoked potentials. Neuroscience 1998; 86:1209-16. [PMID: 9697127 DOI: 10.1016/s0306-4522(98)00107-9] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The use-dependent increase in synaptic strength between primary afferent C-fibres and second-order neurons in superficial spinal dorsal horn may be an important cellular mechanism underlying central hyperalgesia. This long-term potentiation can be blocked by antagonists of the N-methyl-D-aspartate subtype of glutamate receptor, the neurokinin 1 or the neurokinin 2 receptor. We have tested here whether activation of these receptors by superfusion of the spinal cord with corresponding agonists in the absence of presynaptic activity is sufficient to induce long-term potentiation. In urethane anaesthetized rats C-fibre-evoked field potentials were elicited in superficial laminae of lumbar spinal cord by electrical stimulation of the sciatic nerve. In rats with intact spinal cord, controlled superfusion of the spinal cord at recording segments for 60 min with N-methyl-D-aspartate, substance P or neurokinin A never induced long-term potentiation. Spinal superfusion with a mixture of N-methyl-D-aspartate, substance P and neurokinin A also failed to induce long-term potentiation in four rats tested. In spinalized rats, however, long-term potentiation was induced by either N-methyl-D-aspartate (at 10 microM, to 173 +/- 16% of control) substance P (at 10 microM, to 176 +/- 13% of control) or by neurokinin A (at 1 microM, to 198 +/- .20% of control). The induction of long-term potentiation by N-methyl-D-aspartate, substance P or neurokinin A was blocked by intravenous application of the receptor antagonists dizocilpine maleate (0.5 mg/kg), RP67580 (2 mg/kg) or SR48968 (0.2 mg/kg), respectively. Thus, activation of N-methyl-D-aspartate or neurokinin receptors may induce long-lasting plastic changes in synaptic transmission in afferent C-fibres and this effect may be prevented by tonic descending inhibition.
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Affiliation(s)
- X G Liu
- II. Physiologisches Institut, Universität Heidelberg, Germany
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