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Qian Z, Zhang M, Lu T, Yu J, Yin S, Wang H, Wang J. Propolis alleviates ulcerative colitis injury by inhibiting the protein kinase C - transient receptor potential cation channel subfamily V member 1 - calcitonin gene-related peptide/substance P (PKC-TRPV1-CGRP/SP) signaling axis. PLoS One 2024; 19:e0294169. [PMID: 38206948 PMCID: PMC10783729 DOI: 10.1371/journal.pone.0294169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 10/27/2023] [Indexed: 01/13/2024] Open
Abstract
This study investigated the protective effect of water-soluble propolis (WSP) on colonic tissues in ulcerative colitis (UC) and the role of the protein kinase C - transient receptor potential cation channel subfamily V member 1 - calcitonin gene-related peptide/substance P (PKC-TRPV1-CGRP/SP) signaling pathway. Male SD rats were divided into a control group, a UC model group, various WSP groups (Low-WSP, Medium-WSP, and High-WSP) with UC, and a salazosulfapyridine (SASP) positive control group with UC. After UC was established, the WSP and SASP groups were treated with WSP or SASP, respectively, for 7 d. Each day, body weight measurements were obtained, and the disease activity index (DAI) was recorded by observing fecal characteristics and blood in the stool. After the experiment, hematoxylin and eosin (HE) colonic tissue staining was performed to observe pathological changes, western blotting and immunohistochemistry were performed to detect PKC, TRPV1, CGRP, and SP expression in colonic tissues, and laser confocal microscopy was performed to observe the fluorescence colocalization of PKC/TRPV1, TRPV1/CGRP, and TRPV1/SP. HE staining showed significant colonic tissue structure disruption and inflammatory infiltration in the UC group. Western blotting and immunohistochemistry showed that the expression of PKC, TRPV1, CGRP, and SP in the colonic tissues of the UC group increased significantly compared with that of the control group. Compared with the UC group, the expression of PKC, TRPV1, CGRP, and SP in colonic tissues was significantly reduced in the High-WSP, Medium-WSP, and SASP groups. Immunofluorescence showed the colocalized expression of PKC/TRPV1, TRPV1/CGRP, and TRPV1/SP proteins in the colon tissue of the UC group was significantly reduced after WSP and SASP interventions compared with that of the control group. The results suggest that the mechanism of UC alleviation by propolis may inhibit the PKC-TRPV1-CGRP/SP signaling pathway and the release of inflammatory mediators, thus alleviating inflammation.
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Affiliation(s)
- Zhen Qian
- School of Clinical Medicine, Wannan Medical College, Wuhu, Anhui province, China
| | - Mengjie Zhang
- Graduate School, Wannan Medical College, Wuhu, Anhui province, China
| | - Taiyu Lu
- School of Clinical Medicine, Wannan Medical College, Wuhu, Anhui province, China
| | - Jiayi Yu
- School of Clinical Medicine, Wannan Medical College, Wuhu, Anhui province, China
| | - Siyuan Yin
- School of Medical Imageology, Wannan Medical College, Wuhu, Anhui province, China
| | - Haihua Wang
- Department of Physiology, School of Basic Medical Sciences, Wannan Medical College, Wuhu, Anhui province, China
| | - Jing Wang
- Department of Physiology, School of Basic Medical Sciences, Wannan Medical College, Wuhu, Anhui province, China
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Mohamed T, Colciago A, Montagnani Marelli M, Moretti RM, Magnaghi V. Protein kinase C epsilon activation regulates proliferation, migration, and epithelial to mesenchymal-like transition in rat Schwann cells. Front Cell Neurosci 2023; 17:1237479. [PMID: 37645595 PMCID: PMC10461112 DOI: 10.3389/fncel.2023.1237479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
Introduction Protein kinase type C-ε (PKCε) plays an important role in the sensitization of primary afferent nociceptors, promoting mechanical hyperalgesia. In accordance, we showed that PKCε is present in sensory neurons of the peripheral nervous system (PNS), participating in the control of pain onset and chronification. Recently, it was found that PKCε is also implicated in the control of cell proliferation, promoting mitogenesis and metastatic invasion in some types of cancer. However, its role in the main glial cell of the PNS, the Schwann cells (SCs), was still not investigated. Methods Rat primary SCs culture were treated with different pharmacologic approaches, including the PKCε agonist dicyclopropyl-linoleic acid (DCP-LA) 500 nM, the human recombinant brain derived neurotrophic factor (BDNF) 1 nM and the TrkB receptor antagonist cyclotraxin B 10 nM. The proliferation (by cell count), the migration (by scratch test and Boyden assay) as well as some markers of SCs differentiation and epithelial-mesenchymal transition (EMT) process (by qRT-PCR and western blot) were analyzed. Results Overall, we found that PKCε is constitutively expressed in SCs, where it is likely involved in the switch from the proliferative toward the differentiated state. Indeed, we demonstrated that PKCε activation regulates SCs proliferation, increases their migration, and the expression of some markers (e.g., glycoprotein P0 and the transcription factor Krox20) of SCs differentiation. Through an autocrine mechanism, BDNF activates TrkB receptor, and controls SCs proliferation via PKCε. Importantly, PKCε activation likely promoted a partial EMT process in SCs. Discussion PKCε mediates relevant actions in the neuronal and glial compartment of the PNS. In particular, we posit a novel function for PKCε in the transformation of SCs, assuming a role in the mechanisms controlling SCs' fate and plasticity.
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Affiliation(s)
| | | | | | | | - Valerio Magnaghi
- Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, University of Milan, Milan, Italy
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3
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Cabañero D, Villalba-Riquelme E, Fernández-Ballester G, Fernández-Carvajal A, Ferrer-Montiel A. ThermoTRP channels in pain sexual dimorphism: new insights for drug intervention. Pharmacol Ther 2022; 240:108297. [PMID: 36202261 DOI: 10.1016/j.pharmthera.2022.108297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/25/2022] [Accepted: 09/29/2022] [Indexed: 11/30/2022]
Abstract
Chronic pain is a major burden for the society and remains more prevalent and severe in females. The presence of chronic pain is linked to persistent alterations in the peripheral and the central nervous system. One of the main types of peripheral pain transducers are the transient receptor potential channels (TRP), also known as thermoTRP channels, which intervene in the perception of hot and cold external stimuli. These channels, and especially TRPV1, TRPA1 and TRPM8, have been subjected to profound investigation because of their role as thermosensors and also because of their implication in acute and chronic pain. Surprisingly, their sensitivity to endogenous signaling has been far less studied. Cumulative evidence suggests that the function of these channels may be differently modulated in males and females, in part through sexual hormones, and this could constitute a significant contributor to the sex differences in chronic pain. Here, we review the exciting advances in thermoTRP pharmacology for males and females in two paradigmatic types of chronic pain with a strong peripheral component: chronic migraine and chemotherapy-induced peripheral neuropathy (CIPN). The possibilities of peripheral druggability offered by these channels and the differential exploitation for men and women represent a development opportunity that will lead to a significant increment of the armamentarium of analgesic medicines for personalized chronic pain treatment.
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Affiliation(s)
- David Cabañero
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universitas Miguel Hernández, 03202 Elche, Spain
| | - Eva Villalba-Riquelme
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universitas Miguel Hernández, 03202 Elche, Spain
| | - Gregorio Fernández-Ballester
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universitas Miguel Hernández, 03202 Elche, Spain
| | - Asia Fernández-Carvajal
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universitas Miguel Hernández, 03202 Elche, Spain
| | - Antonio Ferrer-Montiel
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universitas Miguel Hernández, 03202 Elche, Spain.
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Activation of PKCε-ALDH2 Axis Prevents 4-HNE-Induced Pain in Mice. Biomolecules 2021; 11:biom11121798. [PMID: 34944441 PMCID: PMC8698646 DOI: 10.3390/biom11121798] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 01/28/2023] Open
Abstract
Protein kinase Cε (PKCε) is highly expressed in nociceptor neurons and its activation has been reported as pro-nociceptive. Intriguingly, we previously demonstrated that activation of the mitochondrial PKCε substrate aldehyde dehydrogenase-2 (ALDH2) results in anti-nociceptive effects. ALDH2 is a major enzyme responsible for the clearance of 4-hydroxy-2-nonenal (4-HNE), an oxidative stress byproduct accumulated in inflammatory conditions and sufficient to induce pain hypersensitivity in rodents. Here we determined the contribution of the PKCε-ALDH2 axis during 4-HNE-induced mechanical hypersensitivity. Using knockout mice, we demonstrated that PKCε is essential for the nociception recovery during 4-HNE-induced hypersensitivity. We also found that ALDH2 deficient knockin mice display increased 4-HNE-induced nociceptive behavior. As proof of concept, the use of a selective peptide activator of PKCε (ΨεHSP90), which favors PKCε translocation to mitochondria and activation of PKCε-ALDH2 axis, was sufficient to block 4-HNE-induced hypersensitivity in WT, but not in ALDH2-deficient mice. Similarly, ΨεHSP90 administration prevented mechanical hypersensitivity induced by endogenous production of 4-HNE after carrageenan injection. These findings provide evidence that selective activation of mitochondrial PKCε-ALDH2 axis is important to mitigate aldehyde-mediated pain in rodents, suggesting that ΨεHSP90 and small molecules that mimic it may be a potential treatment for patients with pain.
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Abdelkader NF, Ibrahim SM, Moustafa PE, Elbaset MA. Inosine mitigated diabetic peripheral neuropathy via modulating GLO1/AGEs/RAGE/NF-κB/Nrf2 and TGF-β/PKC/TRPV1 signaling pathways. Biomed Pharmacother 2021; 145:112395. [PMID: 34775239 DOI: 10.1016/j.biopha.2021.112395] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/20/2021] [Accepted: 11/02/2021] [Indexed: 12/12/2022] Open
Abstract
Inosine is a dietary supplement that is widely used for managing numerous central neurological disorders. Interestingly, recent experimental investigation of inosine revealed its potential to promote peripheral neuroprotection after sciatic nerve injury. Such investigation has guided the focus of the current study to expose the potential of inosine in mitigating diabetic peripheral neuropathy (DPN) in rats and to study the possible underlying signaling pathways. Adult male Wistar rats were arbitrarily distributed into four groups. In the first group, animals received saline daily for 15 days whereas rats of the remaining groups received a single injection of both nicotinamide (50 mg/Kg/i.p.) and streptozotocin (52.5 mg/Kg/i.p.) for DPN induction. Afterward, inosine (10 mg/Kg/p.o.) was administered to two groups, either alone or in combination with caffeine (3.75 mg/Kg/p.o.), an adenosine receptor antagonist. As a result, inosine showed a hypoglycemic effect, restored the sciatic nerve histological structure, enhanced myelination, modulated conduction velocities and maintained behavioral responses. Furthermore, inosine increased GLO1, reduced AGE/RAGE axis and oxidative stress which in turn, downregulated NF-κB p65 and its phosphorylated form in the sciatic nerves. Inosine enhanced Nrf2 expression and its downstream molecule HO-1, resulting in increased CAT and SOD along with lowered MDA. Moreover, pain was relieved due to suppression of PKC and TRPV1 expression, which ultimately lead to reduced SP and TGF-β. The potential effects of inosine were nearly blocked by caffeine administration; this emphasizes the role of adenosine receptors in inosine-mediated neuroprotective effects. In conclusion, inosine alleviated hyperglycemia-induced DPN via modulating GLO1/AGE/RAGE/NF-κB p65/Nrf2 and TGF-β/PKC/TRPV1/SP pathways.
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Affiliation(s)
- Noha F Abdelkader
- Cairo University, Faculty of Pharmacy, Department of Pharmacology and Toxicology, Cairo, Egypt.
| | - Sherehan M Ibrahim
- Cairo University, Faculty of Pharmacy, Department of Pharmacology and Toxicology, Cairo, Egypt
| | - Passant E Moustafa
- National Research center, Medical Division, Department of Pharmacology, Cairo, Egypt
| | - Marawan A Elbaset
- National Research center, Medical Division, Department of Pharmacology, Cairo, Egypt
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Zhao X, Xia B, Cheng J, Zhu MX, Li Y. PKCε SUMOylation Is Required for Mediating the Nociceptive Signaling of Inflammatory Pain. Cell Rep 2020; 33:108191. [DOI: 10.1016/j.celrep.2020.108191] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 07/27/2020] [Accepted: 09/02/2020] [Indexed: 12/20/2022] Open
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Polli A, Godderis L, Ghosh M, Ickmans K, Nijs J. Epigenetic and miRNA Expression Changes in People with Pain: A Systematic Review. THE JOURNAL OF PAIN 2020; 21:763-780. [DOI: 10.1016/j.jpain.2019.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 09/30/2019] [Accepted: 12/02/2019] [Indexed: 01/13/2023]
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Yin N, Gao Q, Tao W, Chen J, Bi J, Ding F, Wang Z. Paeoniflorin relieves LPS-induced inflammatory pain in mice by inhibiting NLRP3 inflammasome activation via transient receptor potential vanilloid 1. J Leukoc Biol 2020; 108:229-241. [PMID: 32083340 DOI: 10.1002/jlb.3ma0220-355r] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 02/03/2020] [Accepted: 02/10/2020] [Indexed: 12/13/2022] Open
Abstract
LPS has been widely used to induce inflammatory pain, attributing to production of inflammatory cytokines and sensitization of nociceptors. Paeoniflorin (PF) possesses anti-nociceptive property, but its effect on LPS-induced inflammatory pain has not been investigated. In this study, we aimed to investigate the analgesic effect of PF on an inflammatory pain mouse model and explore the underlying mechanisms. LPS-induced inflammatory pain model was established in C57BL/6J mice after PF treatment. Then, thermal hyperalgesia, neutrophil infiltration, inflammatory cytokine production, intracellular Ca2+ levels, PKC activity, transient receptor potential vanilloid 1 (TRPV-1) expression, NF-κB transcription, and NLPR3 inflammasome activation were assessed by thermal withdrawal latency, histopathology, ELISA, intracellular Ca2+ concentration, immunohistochemistry, and Western blot, separately. PF significantly relieved inflammatory pain and paw edema in mice with LPS-induced inflammatory pain. Additionally, PF inhibited neutrophil infiltration, inflammatory cytokine production (IL-1β, TNF-α, and IL-6), intracellular Ca2+ levels, and PKC activity as well as suppressed TRPV-1 expression, NF-κB transcription, and NLPR3 inflammasome activation in the footpad tissue samples. Importantly, capsaicin (TRPV-1 agonists) obviously reversed the pain-relieving effect of PF, suggesting the involvement of TRPV-1 in the analgesic activity of PF. Our results indicated PF ameliorated LPS-induced inflammation and pain in mice by inhibiting TRPV-1-mediated NLRP3 inflammasome activation. These findings suggest that PF can be as a potential pharmacological agent for inflammatory pain and thus deserves more attention and further investigation.
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Affiliation(s)
- Nina Yin
- Department of Anatomy, School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan, China
| | - Qinghua Gao
- School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan, China
| | - Wenting Tao
- School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan, China
| | - Jiaojiao Chen
- School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan, China
| | - Jing Bi
- Department of Pathogen Biology, School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan, China
| | - Fengmin Ding
- School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan, China
| | - Zhigang Wang
- Department of Pathogen Biology, School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan, China
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Li B, Rui J, Ding X, Chen Y, Yang X. Deciphering the multicomponent synergy mechanisms of SiNiSan prescription on irritable bowel syndrome using a bioinformatics/network topology based strategy. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2019; 63:152982. [PMID: 31299593 DOI: 10.1016/j.phymed.2019.152982] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 05/31/2019] [Accepted: 06/03/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND SiNiSan (SNS) is a traditional Chinese medicine (TCM) prescription that has been widely used in the clinical treatment of irritable bowel syndrome (IBS). However, the underlying active substances and molecular mechanisms remain obscure. PURPOSE A bioinformatics/topology based strategy was proposed for identification of the drug targets, therapeutic agents and molecular mechanisms of SiNiSan against irritable bowel syndrome. MATERIALS AND METHODS In this work, a bioinformatics/network topology based strategy was employed by integrating ADME filtering, text mining, bioinformatics, network topology, Venn analysis and molecular docking to uncover systematically the multicomponent synergy mechanisms. In vivo experimental validation was executed in a Visceral Hypersensitivity (VHS) rat model. RESULTS 76 protein targets and 109 active components of SNS were identified. Bioinformatics analysis revealed that 116 disease pathways associated with IBS therapy could be classified into the 19 statistically enriched functional sub-groups. The multi-functional co-synergism of SNS against IBS were predicted, including inflammatory reaction regulation, oxidative-stress depression regulation and hormone and immune regulation. The multi-component synergetic effects were also revealed on the herbal combination of SNS. The hub-bottleneck genes of the protein networks including PTGS2, CALM2, NOS2, SLC6A3 and MAOB, MAOA, CREB1 could become potential drug targets and Paeoniflorin, Naringin, Glycyrrhizic acid may be candidate agents. Experimental results showed that the potential mechanisms of SiNiSan treatment involved in the suppression of activation of Dopaminergic synapse and Amphetamine addiction signaling pathways, which are congruent with the prediction by the systematic approach. CONCLUSION The integrative investigation based on bioinformatics/network topology strategy may elaborate the multicomponent synergy mechanisms of SNS against IBS and provide the way out to develop new combination medicines for IBS.
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Affiliation(s)
- Bangjie Li
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Junqian Rui
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Xuejian Ding
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Yifan Chen
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Xinghao Yang
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.
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Deletion of the murine ATP/UTP receptor P2Y2 alters mechanical and thermal response properties in polymodal cutaneous afferents. Neuroscience 2016; 332:223-30. [PMID: 27393251 DOI: 10.1016/j.neuroscience.2016.06.054] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 06/27/2016] [Accepted: 06/29/2016] [Indexed: 12/18/2022]
Abstract
P2Y2 is a member of the P2Y family of G protein-coupled nucleotide receptors that is widely co-expressed with TRPV1 in peripheral sensory neurons of the dorsal root ganglia. To characterize P2Y2 function in cutaneous afferents, intracellular recordings from mouse sensory neurons were made using an ex vivo preparation in which hindlimb skin, saphenous nerve, dorsal root ganglia and spinal cord are dissected intact. The peripheral response properties of individual cutaneous C-fibers were analyzed using digitally controlled mechanical and thermal stimuli in male P2Y2(+/+) and P2Y2(-/-) mice. Selected sensory neurons were labeled with Neurobiotin and further characterized by immunohistochemistry. In wildtype preparations, C-fibers responding to both mechanical and thermal stimuli (CMH or CMHC) preferentially bound the lectin marker IB4 and were always immunonegative for TRPV1. Conversely, cells that fired robustly to noxious heat, but were insensitive to mechanical stimuli, were TRPV1-positive and IB4-negative. P2Y2 gene deletion resulted in reduced firing by TRPV1-negative CMH fibers to a range of heat stimuli. However, we also identified an atypical population of IB4-negative, TRPV1-positive CMH fibers. Compared to wildtype CMH fibers, these TRPV1-positive neurons exhibited lower firing rates in response to mechanical stimulation, but had increased firing to noxious heat (43-51°C). Collectively, these results demonstrate that P2Y2 contributes to response properties of cutaneous afferents, as P2Y2 deletion reduces responsiveness of conventional unmyelinated polymodal afferents to heat and appears to result in the acquisition of mechanical responsiveness in a subset of TRPV1-expressing afferents.
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11
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Mathivanan S, Devesa I, Changeux JP, Ferrer-Montiel A. Bradykinin Induces TRPV1 Exocytotic Recruitment in Peptidergic Nociceptors. Front Pharmacol 2016; 7:178. [PMID: 27445816 PMCID: PMC4917537 DOI: 10.3389/fphar.2016.00178] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/06/2016] [Indexed: 01/09/2023] Open
Abstract
Transient receptor potential vanilloid I (TRPV1) sensitization in peripheral nociceptors is a prominent phenomenon that occurs in inflammatory pain conditions. Pro-algesic agents can potentiate TRPV1 activity in nociceptors through both stimulation of its channel gating and mobilization of channels to the neuronal surface in a context dependent manner. A recent study reported that ATP-induced TRPV1 sensitization in peptidergic nociceptors involves the exocytotic release of channels trafficked by large dense core vesicles (LDCVs) that cargo alpha-calcitonin gene related peptide alpha (αCGRP). We hypothesized that, similar to ATP, bradykinin may also use different mechanisms to sensitize TRPV1 channels in peptidergic and non-peptidergic nociceptors. We found that bradykinin notably enhances the excitability of peptidergic nociceptors, and sensitizes TRPV1, primarily through the bradykinin receptor 2 pathway. Notably, bradykinin sensitization of TRPV1 in peptidergic nociceptors was significantly blocked by inhibiting Ca2+-dependent neuronal exocytosis. In addition, silencing αCGRP gene expression, but not substance P, drastically reduced bradykinin-induced TRPV1 sensitization in peptidergic nociceptors. Taken together, these findings indicate that bradykinin-induced sensitization of TRPV1 in peptidergic nociceptors is partially mediated by the exocytotic mobilization of new channels trafficked by αCGRP-loaded LDCVs to the neuronal membrane. Our findings further imply a central role of αCGRP peptidergic nociceptors in peripheral algesic sensitization, and substantiate that inhibition of LDCVs exocytosis is a valuable therapeutic strategy to treat pain, as it concurrently reduces the release of pro-inflammatory peptides and the membrane recruitment of thermoTRP channels.
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Affiliation(s)
| | - Isabel Devesa
- Instituto de Biología Molecular y Celular, Universitas Miguel Hernández Elche, Spain
| | - Jean-Pierre Changeux
- College de FranceParis, France; Centre Nationale de la Recherche Scientifique, Institute Pasteur, Unité de Recherche AssociéeParis, France
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Reinhart B, Goins WF, Harel A, Chaudhry S, Goss JR, Yoshimura N, de Groat WC, Cohen JB, Glorioso JC. An HSV-based library screen identifies PP1α as a negative TRPV1 regulator with analgesic activity in models of pain. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2016; 3:16040. [PMID: 27382601 PMCID: PMC4916946 DOI: 10.1038/mtm.2016.40] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/01/2016] [Accepted: 04/01/2016] [Indexed: 02/06/2023]
Abstract
Transient receptor potential vanilloid 1 (TRPV1) is a pronociceptive cation channel involved in persistent inflammatory and neuropathic pain. Herpes simplex virus (HSV) vector expression of TRPV1 causes cell death in the presence of capsaicin, thereby completely blocking virus replication. Here we describe a selection system for negative regulators of TRPV1 based on rescue of virus replication. HSV-based coexpression of TRPV1 and a PC12 cell-derived cDNA library identified protein phosphatase 1α (PP1α) as a negative regulator of TRPV1, mimicking the activity of “poreless” (PL), a dominant-negative mutant of TRPV1. Vectors expressing PP1α or PL reduced thermal sensitivity following virus injection into rat footpads, but failed to reduce the nocifensive responses to menthol/icilin-activated cold pain or formalin, demonstrating that the activity identified in vitro is functional in vivo with a degree of specificity. This system should prove powerful for identifying other cellular factors that can inhibit ion channel activity.
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Affiliation(s)
- Bonnie Reinhart
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania, USA
| | - William F Goins
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania, USA
| | - Asaff Harel
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania, USA
| | - Suchita Chaudhry
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania, USA
| | - James R Goss
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania, USA
| | - Naoki Yoshimura
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - William C de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania, USA
| | - Justus B Cohen
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania, USA
| | - Joseph C Glorioso
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania, USA
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Kibaly C, Loh H, Law PY. A Mechanistic Approach to the Development of Gene Therapy for Chronic Pain. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 327:89-161. [DOI: 10.1016/bs.ircmb.2016.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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14
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Sinharoy P, Zhang H, Sinha S, Prudner BC, Bratz IN, Damron DS. Propofol restores TRPV1 sensitivity via a TRPA1-, nitric oxide synthase-dependent activation of PKCε. Pharmacol Res Perspect 2015; 3:e00153. [PMID: 26171233 PMCID: PMC4492729 DOI: 10.1002/prp2.153] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 05/07/2015] [Accepted: 05/11/2015] [Indexed: 12/11/2022] Open
Abstract
We previously demonstrated that the intravenous anesthetic, propofol, restores the sensitivity of transient receptor potential vanilloid channel subtype-1 (TRPV1) receptors via a protein kinase C epsilon (PKCε)-dependent and transient receptor potential ankyrin channel subtype-1 (TRPA1)-dependent pathway in sensory neurons. The extent to which the two pathways are directly linked or operating in parallel has not been determined. Using a molecular approach, our objectives of the current study were to confirm that TRPA1 activation directly results in PKCε activation and to elucidate the cellular mechanism by which this occurs. F-11 cells were transfected with complimentary DNA (cDNA) for TRPV1 only or both TRPV1 and TRPA1. Intracellular Ca(2+) concentration was measured in individual cells via fluorescence microscopy. An immunoblot analysis of the total and phosphorylated forms of PKCε, nitric oxide synthase (nNOS), and TRPV1 was also performed. In F-11 cells containing both channels, PKCε inhibition prevented the propofol- and allyl isothiocyanate (AITC)-induced restoration of TRPV1 sensitivity to agonist stimulation as well as increased phosphorylation of PKCε and TRPV1. In cells containing TRPV1 only, neither agonist induced PKCε or TRPV1 phosphorylation. Moreover, NOS inhibition blocked propofol-and AITC-induced restoration of TRPV1 sensitivity and PKCε phosphorylation, and PKCε inhibition prevented the nitric oxide donor, SNAP, from restoring TRPV1 sensitivity. Also, propofol-and AITC-induced phosphorylation of nNOS and nitric oxide (NO) production were blocked with the TRPA1-antagonist, HC-030031. These data indicate that the AITC- and propofol-induced restoration of TRPV1 sensitivity is mediated by a TRPA1-dependent, nitric oxide synthase-dependent activation of PKCε.
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Affiliation(s)
- Pritam Sinharoy
- Department of Biological Sciences, Kent State University Kent, Ohio, 44242
| | | | - Sayantani Sinha
- Department of Biological Sciences, Kent State University Kent, Ohio, 44242
| | - Bethany C Prudner
- Department of Biological Sciences, Kent State University Kent, Ohio, 44242
| | - Ian N Bratz
- Department of Integrated Medical Sciences, Northeast Ohio Medical University Rootstown, Ohio
| | - Derek S Damron
- Department of Biological Sciences, Kent State University Kent, Ohio, 44242
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Ann J, Yoon S, Baek J, Kim DH, Lewin NE, Hill CS, Blumberg PM, Lee J. Design and synthesis of protein kinase C epsilon selective diacylglycerol lactones (DAG-lactones). Eur J Med Chem 2014; 90:332-41. [PMID: 25437619 DOI: 10.1016/j.ejmech.2014.11.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/29/2014] [Accepted: 11/11/2014] [Indexed: 10/24/2022]
Abstract
DAG-lactones afford a synthetically accessible, high affinity platform for probing structure activity relationships at the C1 regulatory domain of protein kinase C (PKC). Given the central role of PKC isoforms in cellular signaling, along with their differential biological activities, a critical objective is the design of isoform selective ligands. Here, we report the synthesis of a series of DAG-lactones varying in their side chains, with a particular focus on linoleic acid derivatives. We evaluated their selectivity for PKC epsilon versus PKC alpha both under standard lipid conditions (100% phosphatidylserine, PS) as well as in the presence of a nuclear membrane mimetic lipid mixture (NML). We find that selectivity for PKC epsilon versus PKC alpha tended to be enhanced in the presence of the nuclear membrane mimetic lipid mixture and, for our lead compound, report a selectivity of 32-fold.
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Affiliation(s)
- Jihyae Ann
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea
| | - Suyoung Yoon
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea
| | - Jisoo Baek
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea
| | - Da Hye Kim
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Colin S Hill
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Jeewoo Lee
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea.
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16
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Zhang X, Beckel JM, Daugherty SL, Wang T, Woodcock SR, Freeman BA, de Groat WC. Activation of TRPC channels contributes to OA-NO2-induced responses in guinea-pig dorsal root ganglion neurons. J Physiol 2014; 592:4297-312. [PMID: 25128576 DOI: 10.1113/jphysiol.2014.271783] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Effects of nitro-oleic acid (OA-NO2) on TRP channels were examined in guinea-pig dissociated dorsal root ganglia (DRG) neurons using calcium imaging and patch clamp techniques. OA-NO2 increased intracellular Ca(2+) in 60-80% DRG neurons. 1-Oleoyl-2acetyl-sn-glycerol (OAG), a TRPC agonist, elicited responses in 36% of OA-NO2-sensitive neurons while capsaicin (TRPV1 agonist) or allyl-isothiocyanate (AITC, TRPA1 agonist) elicited responses in only 16% and 10%, respectively, of these neurons. A TRPV1 antagonist (diarylpiperazine, 5 μm) in combination with a TRPA1 antagonist (HC-030031, 30 μm) did not change the amplitude of the Ca(2+) transients or percentage of neurons responding to OA-NO2; however, a reducing agent DTT (50 mm) or La(3+) (50 μm) completely abolished OA-NO2 responses. OA-NO2 also induced a transient inward current associated with a membrane depolarization followed by a prolonged outward current and hyperpolarization in 80% of neurons. The reversal potentials of inward and outward currents were approximately -20 mV and -60 mV, respectively. Inward current was reduced when extracellular Na(+) was absent, but unchanged by niflumic acid (100 μm), a Cl(-) channel blocker. Outward current was abolished in the absence of extracellular Ca(2+) or a combination of two Ca(2+)-activated K(+) channel blockers (iberiotoxin, 100 nm and apamin, 1 μm). BTP2 (1 or 10 μm), a broad spectrum TRPC antagonist, or La(3+) (50 μm) completely abolished OA-NO2 currents. RT-PCR performed on mRNA extracted from DRGs revealed the expression of all seven subtypes of TRPC channels. These results support the hypothesis that OA-NO2 activates TRPC channels other than the TRPV1 and TRPA1 channels already known to be targets in rat and mouse sensory neurons and challenge the prevailing view that electrophilic compounds act specifically on TRPA1 or TRPV1 channels. The modulation of sensory neuron excitability via actions on multiple TRP channels can contribute to the anti-inflammatory effect of OA-NO2.
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Affiliation(s)
- Xiulin Zhang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA Department of Urology, The Second Hospital of Shandong University, Jinan, Shandong, 250032, P. R. China
| | - Jonathan M Beckel
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Stephanie L Daugherty
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Ting Wang
- Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Stephen R Woodcock
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Bruce A Freeman
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - William C de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
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17
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Hiett SC, Owen MK, Li W, Chen X, Riley A, Noblet J, Flores S, Sturek M, Tune JD, Obukhov AG. Mechanisms underlying capsaicin effects in canine coronary artery: implications for coronary spasm. Cardiovasc Res 2014; 103:607-18. [PMID: 24935430 DOI: 10.1093/cvr/cvu152] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
AIMS The TRPV1, transient receptor potential vanilloid type 1, agonist capsaicin is considered to be beneficial for cardiovascular health because it dilates coronary arteries through an endothelial-dependent mechanism and may slow atheroma progression. However, recent reports indicate that high doses of capsaicin may constrict coronary arterioles and even provoke myocardial infarction. Thus far, the mechanisms by which TRPV1 activation modulates coronary vascular tone remain poorly understood. This investigation examined whether there is a synergistic interplay between locally acting vasoconstrictive pro-inflammatory hormones (autacoids) and capsaicin effects in the coronary circulation. METHODS AND RESULTS Experiments were performed in canine conduit coronary artery rings and isolated smooth muscle cells (CASMCs). Isometric tension measurements revealed that 1-10 μM capsaicin alone did not affect resting tension of coronary artery rings. In contrast, in endothelium-intact rings pre-contracted with a Gq/11-coupled FP/TP (prostaglandin F/thromboxane) receptor agonist, prostaglandin F2α (PGF2α; 10 μM), capsaicin first induced transient dilation that was followed by sustained contraction. In endothelium-denuded rings pre-contracted with PGF2α or thromboxane analogue U46619 (1 μM, a TP receptor agonist), capsaicin induced only sustained contraction. Blockers of the TP receptor or TRPV1 significantly inhibited capsaicin effects, but these were still observed in the presence of 50 μM nifedipine and 70 mM KCl. Capsaicin also potentiated 20 mM KCl-induced contractions. Fluorescence imaging experiments in CASMCs revealed that the Gq/11-phospholipase C (PLC)-protein kinase C (PKC) and Ca(2+)-PLC-PKC pathways are likely involved in sensitizing CASMC TRPV1 channels. CONCLUSION Capsaicin alone does not cause contractions in conduit canine coronary artery; however, pre-treatment with pro-inflammatory prostaglandin-thromboxane agonists may unmask capsaicin's vasoconstrictive potential.
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Affiliation(s)
- S Christopher Hiett
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Meredith K Owen
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Wennan Li
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Xingjuan Chen
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ashley Riley
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jillian Noblet
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sarah Flores
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michael Sturek
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Johnathan D Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Alexander G Obukhov
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
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Goss JR, Krisky D, Wechuck J, Wolfe D. Herpes simplex virus-based nerve targeting gene therapy in pain management. J Pain Res 2014; 7:71-9. [PMID: 24470772 PMCID: PMC3901742 DOI: 10.2147/jpr.s36619] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Chronic pain represents a major medical burden not only in terms of suffering but also in terms of economic costs. Traditional medical approaches have so far proven insufficient in treating chronic pain and new approaches are necessary. Gene therapy with herpes simplex virus (HSV)-based vectors offers the ability to directly target specific regions of the neuraxis involved in pain transmission including the primary afferent nociceptor. This opens up new targets to interact with that are either not available to traditional systemic drugs or cannot be adequately acted upon without substantial adverse off-target effects. Having access to the entire neuron, which HSV-based vector gene therapy enables, expands treatment options beyond merely treating symptoms and allows for altering the basic biology of the nerve. In this paper, we discuss several HSV-based gene therapy vectors that our group and others have used to target specific neuronal functions involved in the processing of nociception in order to develop new therapies for the treatment of chronic pain.
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19
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Mogg AJ, Mill CEJ, Folly EA, Beattie RE, Blanco MJ, Beck JP, Broad LM. Altered pharmacology of native rodent spinal cord TRPV1 after phosphorylation. Br J Pharmacol 2013; 168:1015-29. [PMID: 23062150 DOI: 10.1111/bph.12005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 09/06/2012] [Accepted: 09/14/2012] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND AND PURPOSE Evidence suggests that phosphorylation of TRPV1 is an important component underlying its aberrant activation in pathological pain states. To date, the detailed pharmacology of diverse TRPV1 receptor agonists and antagonists has yet to be reported for native TRPV1 under phosphorylating conditions. Our goal was to optimize a relatively high-throughput methodology to allow pharmacological characterization of the native TRPV1 receptor using a spinal cord neuropeptide release assay under naive and phosphorylating states. EXPERIMENTAL APPROACH Herein, we describe characterization of rodent TRPV1 by measurement of CGRP release from acutely isolated lumbar (L1-L6) spinal cord using a 96-well technique that combines use of native, adult tissue with quantitation of CGRP release by ELISA. KEY RESULTS We have studied a diverse panel of TRPV1 agonists and antagonists under basal and phosphorylating conditions. We show that TRPV1-mediated CGRP release is evoked, in a temperature-dependent manner, by a PKC activator, phorbol 12,13-dibutyrate (PDBu); and that treatment with PDBu increases the potency and efficacy of known TRPV1 chemical agonists, in an agonist-specific manner. We also show that the pharmacological profile of diverse TRPV1 antagonists is dependent on whether the stimulus is PDBu or capsaicin. Of note, HPPB was identified as an antagonist of capsaicin-evoked, but a potentiator of PDBu-evoked, CGRP release. CONCLUSIONS AND IMPLICATIONS Our findings indicate that both TRPV1 agonist and antagonist profiles can be differentially altered by PKC activation. These findings may offer new insights for targeting TRPV1 in pain states.
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Affiliation(s)
- A J Mogg
- Neuroscience Research Division, Lilly Research Centre, Eli Lilly & Co. Ltd, Windlesham, Surrey, UK.
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20
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Carracedo S, Braun U, Leitges M. Expression pattern of protein kinase C ϵ during mouse embryogenesis. BMC DEVELOPMENTAL BIOLOGY 2013; 13:16. [PMID: 23639204 PMCID: PMC3668281 DOI: 10.1186/1471-213x-13-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 04/24/2013] [Indexed: 12/29/2022]
Abstract
BACKGROUND Protein kinase C epsilon (PKCϵ) belongs to the novel PKC subfamily, which consists of diacylglycerol dependent- and calcium independent-PKCs. Previous studies have shown that PKCϵ is important in different contexts, such as wound healing or cancer. In this study, we contribute to expand the knowledge on PKCϵ by reporting its expression pattern during murine midgestation using the LacZ reporter gene and immunostaining procedures. RESULTS Sites showing highest PKCϵ expression were heart at ealier stages, and ganglia in older embryos. Other stained domains included somites, bone, stomach, kidney, and blood vessels. CONCLUSIONS The seemingly strong expression of PKCϵ in heart and ganglia shown in this study suggests a important role of this isoform in the vascular and nervous systems during mouse development. However, functional redundancy with other PKCs during midgestation within these domains and others reported here possibly exists since PKCϵ deficient mice do not display obvious embryonic developmental defects.
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Affiliation(s)
- Sergio Carracedo
- Biotechnology Centre of Oslo, University of Oslo, Gaustadalleen 21, Oslo, N-0349, Norway.
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21
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Sugimoto Y, Kojima Y, Inayoshi A, Inoue K, Miura-Kusaka H, Mori K, Saku O, Ishida H, Atsumi E, Nakasato Y, Shirakura S, Toki SI, Shinoda K, Suzuki N. K-685, a TRPV1 Antagonist, Blocks PKC-Sensitized TRPV1 Activation and Improves the Inflammatory Pain in a Rat Complete Freund’s Adjuvant Model. J Pharmacol Sci 2013; 123:256-66. [DOI: 10.1254/jphs.13088fp] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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22
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Goins WF, Cohen JB, Glorioso JC. Gene therapy for the treatment of chronic peripheral nervous system pain. Neurobiol Dis 2012; 48:255-70. [PMID: 22668775 DOI: 10.1016/j.nbd.2012.05.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 05/11/2012] [Accepted: 05/24/2012] [Indexed: 11/30/2022] Open
Abstract
Chronic pain is a major health concern affecting 80 million Americans at some time in their lives with significant associated morbidity and effects on individual quality of life. Chronic pain can result from a variety of inflammatory and nerve damaging events that include cancer, infectious diseases, autoimmune-related syndromes and surgery. Current pharmacotherapies have not provided an effective long-term solution as they are limited by drug tolerance and potential abuse. These concerns have led to the development and testing of gene therapy approaches to treat chronic pain. The potential efficacy of gene therapy for pain has been reported in numerous pre-clinical studies that demonstrate pain control at the level of the spinal cord. This promise has been recently supported by a Phase-I human trial in which a replication-defective herpes simplex virus (HSV) vector was used to deliver the human pre-proenkephalin (hPPE) gene, encoding the natural opioid peptides met- and leu-enkephalin (ENK), to cancer patients with intractable pain resulting from bone metastases (Fink et al., 2011). The study showed that the therapy was well tolerated and that patients receiving the higher doses of therapeutic vector experienced a substantial reduction in their overall pain scores for up to a month post vector injection. These exciting early clinical results await further patient testing to demonstrate treatment efficacy and will likely pave the way for other gene therapies to treat chronic pain.
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Affiliation(s)
- William F Goins
- Dept of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh PA 15219, USA.
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23
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Wu DF, Chandra D, McMahon T, Wang D, Dadgar J, Kharazia VN, Liang YJ, Waxman SG, Dib-Hajj SD, Messing RO. PKCε phosphorylation of the sodium channel NaV1.8 increases channel function and produces mechanical hyperalgesia in mice. J Clin Invest 2012; 122:1306-15. [PMID: 22426212 DOI: 10.1172/jci61934] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 02/08/2012] [Indexed: 12/19/2022] Open
Abstract
Mechanical hyperalgesia is a common and potentially disabling complication of many inflammatory and neuropathic conditions. Activation of the enzyme PKCε in primary afferent nociceptors is a major mechanism that underlies mechanical hyperalgesia, but the PKCε substrates involved downstream are not known. Here, we report that in a proteomic screen we identified the NaV1.8 sodium channel, which is selectively expressed in nociceptors, as a PKCε substrate. PKCε-mediated phosphorylation increased NaV1.8 currents, lowered the threshold voltage for activation, and produced a depolarizing shift in inactivation in wild-type - but not in PKCε-null - sensory neurons. PKCε phosphorylated NaV1.8 at S1452, and alanine substitution at this site blocked PKCε modulation of channel properties. Moreover, a specific PKCε activator peptide, ψεRACK, produced mechanical hyperalgesia in wild-type mice but not in Scn10a-/- mice, which lack NaV1.8 channels. These studies demonstrate that NaV1.8 is an important, direct substrate of PKCε that mediates PKCε-dependent mechanical hyperalgesia.
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Affiliation(s)
- Dai-Fei Wu
- Ernest Gallo Clinic and Research Center, Department of Neurology, UCSF, Emeryville, California 94608, USA
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24
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Palazzo E, Luongo L, de Novellis V, Rossi F, Marabese I, Maione S. Transient receptor potential vanilloid type 1 and pain development. Curr Opin Pharmacol 2012; 12:9-17. [DOI: 10.1016/j.coph.2011.10.022] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 10/27/2011] [Accepted: 10/28/2011] [Indexed: 02/06/2023]
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25
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Chen Y, Tian Q. The role of protein kinase C epsilon in neural signal transduction and neurogenic diseases. Front Med 2011; 5:70-6. [PMID: 21681677 DOI: 10.1007/s11684-011-0119-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 01/11/2011] [Indexed: 01/02/2023]
Abstract
Protein kinase C epsilon (PKC ɛ) is one of major isoforms in novel PKC family. Although it has been extensively characterized in the past decade, the role of PKC ɛ in neuron is still not well understood. Advances in molecular biology have now removed significant barriers to the direct investigation of PKC ɛ functions in vivo, and PKC ɛ has been increasingly implicated in the neural biological functions and associated neurogenic diseases. Recent studies have provided important insights into the influence of PKC ɛ on cortical processing at both the single cell level and network level. These studies provide compelling evidence that PKC ɛ could regulate distinct aspects of neural signal transduction and suggest that the coordinated actions of a number of molecular signals contribute to the specification and differentiation of PKC ɛ signal pathway in the developing brain.
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Affiliation(s)
- Yuan Chen
- Neurobiology Research Center, Zhongshan Medical School, Sun Yat-sen University, Guangzhou, 510080, China.
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26
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Bernal PJ, Bauer EM, Cao R, Maniar S, Mosher M, Chen J, Wang QJ, Glorioso JC, Pitt BR, Watkins SC, St Croix CM. A role for zinc in regulating hypoxia-induced contractile events in pulmonary endothelium. Am J Physiol Lung Cell Mol Physiol 2011; 300:L874-86. [PMID: 21378023 DOI: 10.1152/ajplung.00328.2010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
We previously reported that zinc thiolate signaling contributes to hypoxic contraction of small, nonmuscularized arteries of the lung. The present studies were designed to investigate mechanisms by which hypoxia-released zinc induces contraction in isolated pulmonary endothelial cells and to delineate the signaling pathways involved in zinc-mediated changes in the actin cytoskeleton. We used fluorescence-based imaging to show that hypoxia induced time-dependent increases in actin stress fibers that were reversed by the zinc chelator, N,N,N',N'-tetrakis-(2-pyridylmethyl)-ethylenediamine (TPEN). We further showed that hypoxia-induced phosphorylation of the contractile protein myosin light chain (MLC) and assembly of actin stress fibers were each TPEN sensitive. Hypoxia and zinc-induced inhibition of MLC phosphatase (MLCP) were independent of the regulatory subunit (MYPT1) of MLCP, and therefore hypoxia-released zinc likely inhibits MLCP at its catalytic (PP1) subunit. Inhibition of PKC by Ro-31-8220 and a dominant-negative construct of PKC-ε attenuated hypoxia-induced contraction of isolated pulmonary endothelial cells. Furthermore, zinc-induced phosphorylation of MLC (secondary to inhibition of MLCP) was PKC dependent, and hypoxia-released zinc promoted the phosphorylation of the PKC substrate, CPI-17. Collectively, these data suggest a link between hypoxia, elevations in labile zinc, and activation of PKC, which in turn acts through CPI-17 to inhibit MLCP activity and promote MLC phosphorylation, ultimately inducing stress fiber formation and endothelial cell contraction.
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Affiliation(s)
- Paula J Bernal
- Department of Cell Biology, The University of Pittsburgh, Pennsylvania 15219, USA
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27
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HSV delivery of a ligand-regulated endogenous ion channel gene to sensory neurons results in pain control following channel activation. Mol Ther 2010; 19:500-6. [PMID: 21081904 DOI: 10.1038/mt.2010.246] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Persistent pain remains a tremendous health problem due to both its prevalence and dearth of effective therapeutic interventions. To maximize pain relief while minimizing side effects, current gene therapy-based approaches have mostly exploited the expression of pain inhibitory products or interfered with pronociceptive ion channels. These methods do not enable control over the timing or duration of analgesia, nor titration to analgesic efficacy. Here, we describe a gene therapy strategy that potentially overcomes these limitations by providing exquisite control over therapy with efficacy in clinically relevant models of inflammatory pain. We utilize a herpes simplex viral (HSV) vector (vHGlyRα1) to express a ligand-regulated chloride ion channel, the glycine receptor (GlyR) in targeted sensory afferents; the subsequent exogenous addition of glycine provides the means for temporal and spatial control of afferent activity, and therefore pain. Use of an endogenous inhibitory receptor not normally present on sensory neurons both minimizes immunogenicity and maximizes therapeutic selectivity.
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Wickley PJ, Yuge R, Russell MS, Zhang H, Sulak MA, Damron DS. Propofol modulates agonist-induced transient receptor potential vanilloid subtype-1 receptor desensitization via a protein kinase Cepsilon-dependent pathway in mouse dorsal root ganglion sensory neurons. Anesthesiology 2010; 113:833-44. [PMID: 20808213 DOI: 10.1097/aln.0b013e3181eaa9a0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND The activity of transient receptor potential vanilloid subtype-1 (TRPV1) receptors, key nociceptive transducers in dorsal root ganglion sensory neurons, is enhanced by protein kinase C epsilon (PKCepsilon) activation. The intravenous anesthetic propofol has been shown to activate PKCepsilon. Our objectives were to examine whether propofol modulates TRPV1 function in dorsal root ganglion neurons via activation of PKCepsilon. METHODS Lumbar dorsal root ganglion neurons from wild-type and PKC& epsilon;-null mice were isolated and cultured for 24 h. Intracellular free Ca concentration was measured in neurons by using fura-2 acetoxymethyl ester. The duration of pain-associated behaviors was also assessed. Phosphorylation of PKCepsilon and TRPV1 and the cellular translocation of PKCepsilon from cytosol to membrane compartments were assessed by immunoblot analysis. RESULTS In wild-type neurons, repeated stimulation with capsaicin (100 nm) progressively decreased the transient rise in intracellular free Ca concentration. After desensitization, exposure to propofol rescued the Ca response. The resensitizing effect of propofol was absent in neurons obtained from PKCepsilon-null mice. Moreover, the capsaicin-induced desensitization of TRPV1 was markedly attenuated in the presence of propofol in neurons from wild-type mice but not in neurons from PKCepsilon-null mice. Propofol also prolonged the duration of agonist-induced pain associated behaviors in wild-type mice. In addition, propofol increased phosphorylation of PKCepsilon as well as TRPV1 and stimulated translocation of PKCepsilon from cytosolic to membrane fraction. DISCUSSION Our results indicate that propofol modulates TRPV1 sensitivity to capsaicin and that this most likely occurs through a PKCepsilon-mediated phosphorylation of TRPV1.
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Affiliation(s)
- Peter J Wickley
- Department of Biological Sciences, Kent State University, Kent, Ohio, USA
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29
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Low nociceptor GRK2 prolongs prostaglandin E2 hyperalgesia via biased cAMP signaling to Epac/Rap1, protein kinase Cepsilon, and MEK/ERK. J Neurosci 2010; 30:12806-15. [PMID: 20861385 DOI: 10.1523/jneurosci.3142-10.2010] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Hyperexcitability of peripheral nociceptive pathways is often associated with inflammation and is an important mechanism underlying inflammatory pain. Here we describe a completely novel mechanism via which nociceptor G-protein-coupled receptor kinase 2 (GRK2) contributes to regulation of inflammatory hyperalgesia. We show that nociceptor GRK2 is downregulated during inflammation. In addition, we show for the first time that prostaglandin E2 (PGE2)-induced hyperalgesia is prolonged from <6 h in wild-type (WT) mice to 3 d in mice with low GRK2 in Nav1.8+ nociceptors (SNS-GRK2+/- mice). This prolongation of PGE2 hyperalgesia in SNS-GRK2+/- mice does not depend on changes in the sensitivity of the prostaglandin receptors because prolonged hyperalgesia also developed in response to 8-Br-cAMP. PGE2 or cAMP-induced hyperalgesia in WT mice is PKA dependent. However, PKA activity is not required for hyperalgesia in SNS-GRK2+/- mice. SNS-GRK2+/- mice developed prolonged hyperalgesia in response to the Exchange proteins directly activated by cAMP (Epac) activator 8-pCPT-2'-O-Me-cAMP (8-pCPT). Coimmunoprecipitation experiments showed that GRK2 binds to Epac1. In vitro, GRK2 deficiency increased 8-pCPT-induced activation of the downstream effector of Epac, Rap1, and extracellular signal-regulated kinase (ERK). In vivo, inhibition of MEK1 or PKCε prevented prolonged PGE2, 8-Br-cAMP, and 8-pCPT hyperalgesia in SNS-GRK2+/- mice. In conclusion, we discovered GRK2 as a novel Epac1-interacting protein. A reduction in the cellular level of GRK2 enhances activation of the Epac-Rap1 pathway. In vivo, low nociceptor GRK2 leads to prolonged inflammatory hyperalgesia via biased cAMP signaling from PKA to Epac-Rap1, ERK/PKCε pathways.
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A herpes simplex virus vector system for expression of complex cellular cDNA libraries. J Virol 2010; 84:7360-8. [PMID: 20463073 DOI: 10.1128/jvi.02388-09] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Viral vector-based gene expression libraries from normal or diseased tissues offer opportunities to interrogate cellular functions that influence or participate directly in specific biological processes. Here we report the creation and characterization of a herpes simplex virus (HSV)-based expression library consisting of cDNAs derived from PC12 pheochromocytoma cells. A replication-defective HSV vector backbone was engineered to contain both a bacterial artificial chromosome (BAC) and the Invitrogen in vitro Gateway recombination system, creating DBAC-GW. A cDNA library was produced and transferred into the DBAC-GW genome by in vitro recombination and selection in bacteria to produce DBAC-L. DBAC-L contained at least 15,000 unique cDNAs, as shown by DNA array analysis of PCR-amplified cDNA inserts, representing a wide range of cancer- and neuron-related cellular functions. Transfection of the recombinant DBAC-L DNA into complementing animal cells produced more than 1 million DBAC-L virus particles representing the library genes. By microarray analysis of vector-infected cells, we observed that individual members of this vector population expressed unique PC12 cDNA-derived mRNA, demonstrating the power of this system to transfer and express a variety of gene activities. We discuss the potential utility of this and similarly derived expression libraries for genome-wide approaches to identify cellular functions that participate in complex host-pathogen interactions or processes related to disease and to cell growth and development.
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Joseph EK, Levine JD. Multiple PKCε-dependent mechanisms mediating mechanical hyperalgesia. Pain 2010; 150:17-21. [PMID: 20456866 DOI: 10.1016/j.pain.2010.02.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 01/11/2010] [Accepted: 02/05/2010] [Indexed: 12/14/2022]
Abstract
We have recently implicated mitochondrial mechanisms in models of neuropathic and inflammatory pain, in some of which a role of protein kinase Cepsilon (PKCepsilon) has also been implicated. Since mitochondria contain several proteins that are targets of PKCepsilon, we evaluated the role of mitochondrial mechanisms in mechanical hyperalgesia induced by proinflammatory cytokines that induce PKCepsilon-dependent nociceptor sensitization, and by a direct activator of PKCepsilon (psiepsilonRACK), in the rat. Prostaglandin E(2) (PGE(2))-induced hyperalgesia is short lived in naïve rats, while it is prolonged in psiepsilonRACK pre-treated rats, a phenomenon referred to as priming. Inhibitors of two closely related mitochondrial functions, electron transport (complexes I-V) and oxidative stress (reactive oxygen species), attenuated mechanical hyperalgesia induced by intradermal injection of psiepsilonRACK. In marked contrast, in a PKCepsilon-dependent form of mechanical hyperalgesia induced by prostaglandin E(2) (PGE(2)), inhibitors of mitochondrial function failed to attenuate hyperalgesia. These studies support the suggestion that at least two downstream signaling pathways can mediate the hyperalgesia induced by activating PKCepsilon.
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Affiliation(s)
- Elizabeth K Joseph
- Departments of Medicine and Oral Surgery, and Division of Neuroscience, University of California, San Francisco, USA
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Crouzin N, de Jesus Ferreira MC, Cohen-Solal C, Barbanel G, Guiramand J, Vignes M. Neuroprotection induced by vitamin E against oxidative stress in hippocampal neurons: Involvement of TRPV1 channels. Mol Nutr Food Res 2010; 54:496-505. [DOI: 10.1002/mnfr.200900188] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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HSV vector-mediated modification of primary nociceptor afferents: an approach to inhibit chronic pain. Gene Ther 2010; 16:493-501. [PMID: 19357694 DOI: 10.1038/gt.2009.24] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chronic pain is a serious medical condition with millions of sufferers for whom long-term therapies are either lacking or inadequate. Here we review the use of herpes simplex virus vectors as therapeutic tools to treat chronic pain by gene therapy. We describe an approach to inhibit chronic pain signaling whereby vector-mediated genes transferred to sensory nerves will modify the primary afferent nociceptor to prevent pain signaling to second-order nerves in the spinal cord. This approach may be used to reverse the chronic pain state of the nociceptor and could affect downstream pain-related changes in the central nervous system.
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Sculptoreanu A, Kullmann FA, Artim DE, Bazley FA, Schopfer F, Woodcock S, Freeman BA, de Groat WC. Nitro-oleic acid inhibits firing and activates TRPV1- and TRPA1-mediated inward currents in dorsal root ganglion neurons from adult male rats. J Pharmacol Exp Ther 2010; 333:883-95. [PMID: 20304940 DOI: 10.1124/jpet.109.163154] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nitro-oleic acid (OA-NO(2)), an electrophilic fatty acid by-product of nitric oxide and nitrite reactions, is present in normal and inflamed mammalian tissues at up to micromolar concentrations and exhibits anti-inflammatory signaling actions. The effects of OA-NO(2) on cultured dorsal root ganglion (DRG) neurons were examined using fura-2 Ca(2+) imaging and patch clamping. OA-NO(2) (3.5-35 microM) elicited Ca(2+) transients in 20 to 40% of DRG neurons, the majority (60-80%) of which also responded to allyl isothiocyanate (AITC; 1-50 microM), a TRPA1 agonist, and to capsaicin (CAPS; 0.5 microM), a TRPV1 agonist. The OA-NO(2)-evoked Ca(2+) transients were reduced by the TRPA1 antagonist 2-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7H-purin-7-yl)-N-(4-isopropylphenyl) acetamide (HC-030031; 5-50 microM) and the TRPV1 antagonist capsazepine (10 microM). Patch-clamp recording revealed that OA-NO(2) depolarized and induced inward currents in 62% of neurons. The effects of OA-NO(2) were elicited by concentrations >or=5 nM and were blocked by 10 mM dithiothreitol. Concentrations of OA-NO(2) >or=5 nM reduced action potential (AP) overshoot, increased AP duration, inhibited firing induced by depolarizing current pulses, and inhibited Na(+) currents. The effects of OA-NO(2) were not prevented or reversed by the NO-scavenger carboxy-2-phenyl-4,4,5,5-tetramethylimidazolineoxyl-1-oxyl-3-oxide. A large percentage (46-57%) of OA-NO(2)-responsive neurons also responded to CAPS (0.5 microM) or AITC (0.5 microM). OA-NO(2) currents were reduced by TRPV1 (diarylpiperazine; 5 microM) or TRPA1 (HC-030031; 5 microM) antagonists. These data reveal that endogenous OA-NO(2) generated at sites of inflammation may initially activate transient receptor potential channels on nociceptive afferent nerves, contributing to the initiation of afferent nerve activity, and later suppresses afferent firing.
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Affiliation(s)
- A Sculptoreanu
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania 15261, USA.
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Wolfe D, Wechuck J, Krisky D, Mata M, Fink DJ. A clinical trial of gene therapy for chronic pain. PAIN MEDICINE 2010; 10:1325-30. [PMID: 19818042 DOI: 10.1111/j.1526-4637.2009.00720.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The first human trial of gene therapy for chronic pain, a phase 1 study of a nonreplicating herpes simplex virus (HSV)-based vector engineered to express preproenkephalin in patients with intractable pain from cancer, began enrolling subjects in December 2008. In this article, we describe the rationale underlying this potential approach to treatment of pain, the preclinical animal data in support of this approach, the design of the study, and studies with additional HSV-based vectors that may be used to develop treatment for other types of pain.
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The effects of sympathetic outflow on upregulation of vanilloid receptors TRPV(1) in primary afferent neurons evoked by intradermal capsaicin. Exp Neurol 2009; 222:93-107. [PMID: 20036240 DOI: 10.1016/j.expneurol.2009.12.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 12/09/2009] [Accepted: 12/11/2009] [Indexed: 12/17/2022]
Abstract
The vanilloid receptor TRPV(1) is a key nociceptive molecule located in primary afferent nociceptive neurons in dorsal root ganglia (DRG) for initiating neurogenic inflammation and pain. Our recent study demonstrates that up-regulation of TRPV(1) receptors by intradermal injection of capsaicin is modulated by activation of the protein kinase C (PKC) cascade. Neurogenic inflammation and pain resulting from capsaicin injection are sympathetically dependent, responding to norepinephrine, adenosine 5'-triphosphate (ATP) and/or neuropeptide Y released from sympathetic efferents. In a rat model of acute neurogenic inflammatory pain produced by capsaicin injection, we used immunofluorescence and Western blots combined with pharmacology and surgical sympathectomies to analyze whether the capsaicin-evoked up-regulation of TRPV(1) in DRG neurons is affected by sympathetic outflow by way of activating the PKC cascade. Sympathetic denervation reduced significantly the capsaicin-evoked expressions of TRPV(1), calcitonin gene-related peptide and/or phosphorylated PKC and their co-expression. These reductions could be restored by exogenous pretreatment with an analog of ATP, alpha,beta-methylene ATP. Inhibition of PKC with chelerythrine chloride prevented the ATP effect. Consistent results were obtained from experiments in which capsaicin-evoked changes in cutaneous inflammation (vasodilation and edema) were examined after sympathetic denervation, and the effects of the above pharmacological manipulations were evaluated. Our findings suggest that the capsaicin-evoked up-regulation of TRPV(1) receptors in DRG neurons is modulated sympathetically by the action of ATP released from sympathetic efferents to activate the PKC cascade. Thus, this study proposes a potential new mechanism of sympathetic modulation of neurogenic inflammation.
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Sculptoreanu A, Artim DE, de Groat WC. Neurokinins inhibit low threshold inactivating K+ currents in capsaicin responsive DRG neurons. Exp Neurol 2009; 219:562-73. [PMID: 19631644 DOI: 10.1016/j.expneurol.2009.07.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2009] [Revised: 07/15/2009] [Accepted: 07/15/2009] [Indexed: 10/20/2022]
Abstract
Neurokinins (NK) released from terminals of dorsal root ganglion (DRG) neurons may control firing of these neurons by an autofeedback mechanism. In this study we used patch clamp recording techniques to determine if NKs alter excitability of rat L4-S3 DRG neurons by modulating K(+) currents. In capsaicin (CAPS)-responsive phasic neurons substance P (SP) lowered action potential (AP) threshold and increased the number of APs elicited by depolarizing current pulses. SP and a selective NK(2) agonist, [betaAla(8)]-neurokinin A (4-10) also inhibited low threshold inactivating K(+) currents isolated by blocking non-inactivating currents with a combination of high TEA, (-) verapamil and nifedipine. Currents recorded under these conditions were heteropodatoxin-sensitive (Kv4 blocker) and alpha-dendrotoxin-insensitive (Kv1.1 and Kv1.2 blocker). SP and NKA elicited a >10 mV positive shift of the voltage dependence of activation of the low threshold currents. This effect was absent in CAPS-unresponsive neurons. The effect of SP or NKA on K(+) currents in CAPS-responsive phasic neurons was fully reversed by an NK(2) receptor antagonist (MEN10376) but only partially reversed by a PKC inhibitor (bisindolylmaleimide). An NK(1) selective agonist ([Sar(9), Met(11)]-substance P) or direct activation of PKC with phorbol 12,13-dibutyrate, did not change firing in CAPS-responsive neurons, but did inhibit various types of K(+) currents that activated over a wide range of voltages. These data suggest that the excitability of CAPS-responsive phasic afferent neurons is increased by activation of NK(2) receptors and that this is due in part to inhibition and a positive voltage shift in the activation of heteropodatoxin-sensitive Kv4 channels.
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Affiliation(s)
- Adrian Sculptoreanu
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
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Glorioso JC, Fink DJ. Herpes vector-mediated gene transfer in the treatment of chronic pain. Mol Ther 2008; 17:13-8. [PMID: 18841093 DOI: 10.1038/mt.2008.213] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Chronic pain is a major health concern with up to 50% of patients finding little if any relief following traditional pharmacotherapy. This review describes the treatment of chronic pain using herpes simplex virus type 1 (HSV)-based vectors. HSV can be effectively used to deliver pain-modulating transgenes to sensory neurons in vivo following intradermal inoculation. The vector genome persists in peripheral nerve bodies in an episomal state and serves as a platform for expression of natural pain-relieving molecules that access endogenous antinociceptive circuitry. The vectors are mutated to prevent reactivation from latency or spread to the central nervous system. Dermatome selection for administration of HSV vectors provides targeted delivery of pain gene therapy to primary afferent neurons. This novel approach alleviates pain without systemic side effects or the induction of tolerance and can be used in combination with standard pain treatments.
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Affiliation(s)
- Joseph C Glorioso
- 1Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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