1
|
Li X, Prudente AS, Prato V, Guo X, Hao H, Jones F, Figoli S, Mullen P, Wang Y, Tonello R, Lee SH, Shah S, Maffei B, Berta T, Du X, Gamper N. Peripheral gating of mechanosensation by glial diazepam binding inhibitor. J Clin Invest 2024; 134:e176227. [PMID: 38888973 PMCID: PMC11324294 DOI: 10.1172/jci176227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 06/13/2024] [Indexed: 06/20/2024] Open
Abstract
We report that diazepam binding inhibitor (DBI) is a glial messenger mediating crosstalk between satellite glial cells (SGCs) and sensory neurons in the dorsal root ganglion (DRG). DBI is highly expressed in SGCs of mice, rats, and humans, but not in sensory neurons or most other DRG-resident cells. Knockdown of DBI results in a robust mechanical hypersensitivity without major effects on other sensory modalities. In vivo overexpression of DBI in SGCs reduces sensitivity to mechanical stimulation and alleviates mechanical allodynia in neuropathic and inflammatory pain models. We further show that DBI acts as an unconventional agonist and positive allosteric modulator at the neuronal GABAA receptors, particularly strongly affecting those with a high-affinity benzodiazepine binding site. Such receptors are selectively expressed by a subpopulation of mechanosensitive DRG neurons, and these are also more enwrapped with DBI-expressing glia, as compared with other DRG neurons, suggesting a mechanism for a specific effect of DBI on mechanosensation. These findings identified a communication mechanism between peripheral neurons and SGCs. This communication modulates pain signaling and can be targeted therapeutically.
Collapse
Affiliation(s)
- Xinmeng Li
- Department of Pharmacology; The Key Laboratory of Neural and Vascular Biology, Ministry of Education; The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Arthur Silveira Prudente
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Vincenzo Prato
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Xianchuan Guo
- Department of Pharmacology; The Key Laboratory of Neural and Vascular Biology, Ministry of Education; The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Han Hao
- Department of Pharmacology; The Key Laboratory of Neural and Vascular Biology, Ministry of Education; The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Frederick Jones
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
- Department of Life Sciences, Manchester Metropolitan University, Manchester, United Kingdom
| | - Sofia Figoli
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Pierce Mullen
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Yujin Wang
- Department of Pharmacology; The Key Laboratory of Neural and Vascular Biology, Ministry of Education; The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Raquel Tonello
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Sang Hoon Lee
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Shihab Shah
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Benito Maffei
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Temugin Berta
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Xiaona Du
- Department of Pharmacology; The Key Laboratory of Neural and Vascular Biology, Ministry of Education; The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Nikita Gamper
- Department of Pharmacology; The Key Laboratory of Neural and Vascular Biology, Ministry of Education; The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei, China
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
2
|
Muñoz MF, Griffith TN, Contreras JE. Mechanisms of ATP release in pain: role of pannexin and connexin channels. Purinergic Signal 2021; 17:549-561. [PMID: 34792743 PMCID: PMC8677853 DOI: 10.1007/s11302-021-09822-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 10/18/2021] [Indexed: 12/21/2022] Open
Abstract
Pain is a physiological response to bodily damage and serves as a warning of potential threat. Pain can also transform from an acute response to noxious stimuli to a chronic condition with notable emotional and psychological components that requires treatment. Indeed, the management of chronic pain is currently an important unmet societal need. Several reports have implicated the release of the neurotransmitter adenosine triphosphate (ATP) and subsequent activation of purinergic receptors in distinct pain etiologies. Purinergic receptors are broadly expressed in peripheral neurons and the spinal cord; thus, purinergic signaling in sensory neurons or in spinal circuits may be critical for pain processing. Nevertheless, an outstanding question remains: what are the mechanisms of ATP release that initiate nociceptive signaling? Connexin and pannexin channels are established conduits of ATP release and have been suggested to play important roles in a variety of pathologies, including several models of pain. As such, these large-pore channels represent a new and exciting putative pharmacological target for pain treatment. Herein, we will review the current evidence for a role of connexin and pannexin channels in ATP release during nociceptive signaling, such as neuropathic and inflammatory pain. Collectively, these studies provide compelling evidence for an important role of connexins and pannexins in pain processing.
Collapse
Affiliation(s)
- Manuel F. Muñoz
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, USA
| | - Theanne N. Griffith
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, USA
| | - Jorge E. Contreras
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, USA
| |
Collapse
|
3
|
Shin SM, Itson-Zoske B, Cai Y, Qiu C, Pan B, Stucky CL, Hogan QH, Yu H. Satellite glial cells in sensory ganglia express functional transient receptor potential ankyrin 1 that is sensitized in neuropathic and inflammatory pain. Mol Pain 2021; 16:1744806920925425. [PMID: 32484015 PMCID: PMC7268132 DOI: 10.1177/1744806920925425] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Transient receptor potential ankyrin 1 (TRPA1) is well documented as an important molecule in pain hypersensitivity following inflammation and nerve injury and in many other cellular biological processes. Here, we show that TRPA1 is expressed not only by sensory neurons of the dorsal root ganglia (DRG) but also in their adjacent satellite glial cells (SGCs), as well as nonmyelinating Schwann cells. TRPA1 immunoreactivity is also detected in various cutaneous structures of sensory neuronal terminals, including small and large caliber cutaneous sensory fibers and endings. The SGC-expressed TRPA1 is functional. Like DRG neurons, dissociated SGCs exhibit a robust response to the TRPA1-selective agonist allyl isothiocyanate (AITC) by an increase of intracellular Ca2+ concentration ([Ca2+]i). These responses are abolished by the TRPA1 antagonist HC030031 and are absent in SGCs and neurons from global TRPA1 null mice. SGCs and neurons harvested from DRG proximal to painful tissue inflammation induced by plantar injection of complete Freund’s adjuvant show greater AITC-evoked elevation of [Ca2+]i and slower recovery compared to sham controls. Similar TRPA1 sensitization occurs in both SGCs and neurons during neuropathic pain induced by spared nerve injury. Together, these results show that functional TRPA1 is expressed by sensory ganglia SGCs, and TRPA1 function in SGCs is enhanced after both peripheral inflammation and nerve injury, and suggest that TRPA1 in SGCs may contribute to inflammatory and neuropathic pain.
Collapse
Affiliation(s)
- Seung Min Shin
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Clement J. Zablocki VA Medical Center, Milwaukee, WI, USA
| | - Brandon Itson-Zoske
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Yongsong Cai
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Xi'an Jiaotong University Health Science Center, Xi'an, P.R. China
| | - Chensheng Qiu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Orthopedic Surgery, Affiliated Hospital of Qingdao University, Qingdao, P.R. China
| | - Bin Pan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Cheryl L Stucky
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Quinn H Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Clement J. Zablocki VA Medical Center, Milwaukee, WI, USA
| | - Hongwei Yu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Clement J. Zablocki VA Medical Center, Milwaukee, WI, USA
| |
Collapse
|
4
|
Regulation of Mitochondrial Function by Epac2 Contributes to Acute Inflammatory Hyperalgesia. J Neurosci 2021; 41:2883-2898. [PMID: 33593853 DOI: 10.1523/jneurosci.2368-20.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 01/14/2021] [Accepted: 02/09/2021] [Indexed: 12/12/2022] Open
Abstract
Gαs-coupled receptors signaling through cAMP provide a key mechanism for the sensitization of nociceptive sensory neurons, and the cAMP effector Epac has been implicated in the transition from acute to chronic pain. Epac exerts its effects through Rap1 and protein kinase C (PKC). To identify targets of Epac-PKC signaling in sensory neurons of the mouse dorsal root ganglion (DRG), we profiled PKC substrate proteins phosphorylated in response to the activation of Epac with the proinflammatory prostaglandin E2 (PGE2). A prominent Epac-dependent phospho-protein band induced by PGE2 was identified by mass spectrometry as the mitochondrial enzyme pyruvate dehydrogenase (Pdha1). In dissociated DRG from both males and females, the recruitment of Pdha1 to phospho-protein fractions was rapidly induced by PGE2 and prevented by selective inhibition of Epac2. Epac activation increased mitochondrial respiration, consistent with an increase in Pdha1 function mediated by Epac2. Hindpaw injection of PGE2 induced heat hyperalgesia in males and females, but Pdha1 phosphorylation occurred only in males. Hyperalgesia was attenuated in males but not in females by systemic inhibition of Epac2, and also by a mitochondrial membrane potential uncoupler, dinitrophenol, supporting a role for mitochondrial regulation in acute hyperalgesia. These findings identify a mechanism for the regulation of mitochondrial function by Epac2 that contributes to acute inflammatory hyperalgesia in male mice. Systemic administration of the cyclooxygenase 2 inhibitor celecoxib suppressed both PGE2-induced heat hyperalgesia and Pdha1 phosphorylation in DRG of males but not females, suggesting that prostaglandin synthesis within the DRG mediates the phosphorylation of Pdha1 in response to hindpaw insult.SIGNIFICANCE STATEMENT There has been extensive investigation of mitochondrial dysfunction as a causative factor in neuropathic pain disorders. In contrast, results reported here implicate enhanced mitochondrial function as a contributing factor in the development of acute inflammatory hyperalgesia. We describe a mechanism in which Epac2 activation by prostaglandin receptors leads to phosphorylation of pyruvate dehydrogenase and an increase in mitochondrial respiration in peripheral sensory neurons. Although Epac2 activation leads to Pdha1 (pyruvate dehydrogenase) phosphorylation in dissociated neurons from mice of both sexes, induction of this pathway in vivo by hindpaw insult is restricted to males and appears to require intraganglionic prostaglandin synthesis. These findings support a model in which Gs-coupled receptor modulation of mitochondrial function promotes acute nociceptive signaling and inflammatory hyperalgesia.
Collapse
|
5
|
Magown P, Ko AL, Burchiel KJ. The Spectrum of Trigeminal Neuralgia Without Neurovascular Compression. Neurosurgery 2020; 85:E553-E559. [PMID: 31329945 DOI: 10.1093/neuros/nyz048] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 01/29/2019] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND In trigeminal neuralgia type 1 (TN1), neurovascular compression (NVC) is often assumed to be the pain initiating mechanism. NVC can be surgically addressed by microvascular decompression (MVD). However, some patients with TN1 present without NVC (WONVC). OBJECTIVE To characterize and analyze the clinical spectrum of a TN1 patient population WONVC. METHODS A retrospective chart review of patients presenting with TN1 between 2007 and 2017 was performed. Patients who were potential candidates for MVD surgery underwent high-resolution imaging with 3-dimensional (3D) reconstruction to address the presence, or absence, of NVC. Demographic data about the populations with NVC (WNVC) and WONVC were collected. RESULTS Of 242 patients with TN1, 32% did not have NVC. Patients WONVC were on average 10.6 yr younger than those WNVC. TN1 onset in patients WONVC was more frequent below 48.7 yr, and the opposite was found in patients WNVC. Compared to patients WNVC, those WONVC were predominantly female (odds ratio 4.8), on average were 4 yr younger at symptom onset (34.7 yr) and 7.8 yr younger at first clinic visit, and had a 3.7 yr shorter symptom duration. CONCLUSION Patients presenting with TN1 WONVC were predominantly females in their mid-30s with short symptom duration. In the absence of NVC, this subgroup of TN1 patients has limited surgical options, and potentially a longer condition duration that must be managed medically or surgically. This population WONVC might provide insights into the true pathophysiology of TN1.
Collapse
Affiliation(s)
- Philippe Magown
- Neurosurgery, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Andrew L Ko
- Neurological Surgery, University of Washington Medical Center, Seattle, Washington
| | - Kim J Burchiel
- Neurological Surgery, Oregon Health & Science University, Portland, Oregon
| |
Collapse
|
6
|
De-Miguel FF, Leon-Pinzon C, Noguez P, Mendez B. Serotonin release from the neuronal cell body and its long-lasting effects on the nervous system. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0196. [PMID: 26009775 PMCID: PMC4455765 DOI: 10.1098/rstb.2014.0196] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Serotonin, a modulator of multiple functions in the nervous system, is released predominantly extrasynaptically from neuronal cell bodies, axons and dendrites. This paper describes how serotonin is released from cell bodies of Retzius neurons in the central nervous system (CNS) of the leech, and how it affects neighbouring glia and neurons. The large Retzius neurons contain serotonin packed in electrodense vesicles. Electrical stimulation with 10 impulses at 1 Hz fails to evoke exocytosis from the cell body, but the same number of impulses at 20 Hz promotes exocytosis via a multistep process. Calcium entry into the neuron triggers calcium-induced calcium release, which activates the transport of vesicle clusters to the plasma membrane. Exocytosis occurs there for several minutes. Serotonin that has been released activates autoreceptors that induce an inositol trisphosphate-dependent calcium increase, which produces further exocytosis. This positive feedback loop subsides when the last vesicles in the cluster fuse and calcium returns to basal levels. Serotonin released from the cell body is taken up by glia and released elsewhere in the CNS. Synchronous bursts of neuronal electrical activity appear minutes later and continue for hours. In this way, a brief train of impulses is translated into a long-term modulation in the nervous system.
Collapse
Affiliation(s)
- Francisco F De-Miguel
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, Circuito Exterior SN, Ciudad Universitaria, Distrito Federal, Mexico
| | - Carolina Leon-Pinzon
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, Circuito Exterior SN, Ciudad Universitaria, Distrito Federal, Mexico
| | - Paula Noguez
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, Circuito Exterior SN, Ciudad Universitaria, Distrito Federal, Mexico
| | - Bruno Mendez
- Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, Circuito Exterior SN, Ciudad Universitaria, Distrito Federal, Mexico
| |
Collapse
|
7
|
Zhu H, Yu Y, Zheng L, Wang L, Li C, Yu J, Wei J, Wang C, Zhang J, Xu S, Wei X, Cui W, Wang Q, Chen X. Chronic inflammatory pain upregulates expression of P2Y2 receptor in small-diameter sensory neurons. Metab Brain Dis 2015; 30:1349-58. [PMID: 26062804 DOI: 10.1007/s11011-015-9695-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/01/2015] [Indexed: 11/28/2022]
Abstract
Roles of ionotropic purinergic (P2X) receptors in chronic pain have been intensively investigated. However, the contribution of metabotropic purinergic (P2Y) receptors to pathological pain is controversial. In the present study, using single cell RT-PCR (reverse transcription-polymerase chain reaction) and single cell nested-PCR techniques, we examined the expression of P2X(2), P2X(3), P2Y(1) and P2Y(2) mRNA transcripts in retrogradely labeled cutaneous sensory neurons from mouse lumber dorsal root ganglia (DRGs) following peripheral inflammation. The percentage of cutaneous sensory neurons expressing P2Y(2) mRNA transcripts increased after complete Freund's adjuvant (CFA) treatment. Particularly, the P2Y(2) mRNA transcripts were more frequently detected in small-diameter cutaneous neurons from CFA-treated mice than those from control mice. Coexpression of P2Y(2) and P2X (P2X(2) or P2X(3)) mRNAs was more frequently observed in cutaneous sensory neurons from CFA-treated mice relative to controls. Pain behavioral tests showed that the blockade of P2Y receptors by suramin attenuated mechanical allodynia evoked either by CFA or uridine triphosphate (UTP), an endogenous P2Y(2) and P2Y(4) agonist. These results suggest that chronic inflammatory pain enhances expression of P2Y(2) receptor in peripheral sensory neurons that innervate the injured tissue and the activation of P2Y receptors contributes to mechanical allodynia following inflammation.
Collapse
MESH Headings
- Animals
- Arthritis, Experimental/metabolism
- Arthritis, Experimental/psychology
- Behavior, Animal
- Chronic Pain/etiology
- Chronic Pain/metabolism
- Chronic Pain/psychology
- Ganglia, Spinal/cytology
- Ganglia, Spinal/metabolism
- Hyperalgesia/chemically induced
- Hyperalgesia/metabolism
- Hyperalgesia/psychology
- Inflammation/complications
- Inflammation/metabolism
- Inflammation/psychology
- Mice
- Mice, Inbred ICR
- Nociception
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptors, Purinergic P2Y/biosynthesis
- Receptors, Purinergic P2Y/genetics
- Receptors, Purinergic P2Y2/biosynthesis
- Receptors, Purinergic P2Y2/genetics
- Sensory Receptor Cells/metabolism
- Sensory Receptor Cells/pathology
- Skin/innervation
- Up-Regulation
Collapse
Affiliation(s)
- Huiqin Zhu
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Yi Yu
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Lingyan Zheng
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Lu Wang
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Chenli Li
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Jiangyuan Yu
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Jing Wei
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Chuang Wang
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Junfang Zhang
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Shujun Xu
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Xiaofei Wei
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Wei Cui
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Qinwen Wang
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China
| | - Xiaowei Chen
- Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, 315211, China.
| |
Collapse
|
8
|
Magni G, Merli D, Verderio C, Abbracchio MP, Ceruti S. P2Y2 receptor antagonists as anti-allodynic agents in acute and sub-chronic trigeminal sensitization: role of satellite glial cells. Glia 2015; 63:1256-69. [PMID: 25779655 DOI: 10.1002/glia.22819] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/28/2015] [Accepted: 02/27/2015] [Indexed: 12/18/2022]
Abstract
Trigeminal (TG) pain often lacks a satisfactory pharmacological control. A better understanding of the molecular cross-talk between TG neurons and surrounding satellite glial cells (SGCs) could help identifying innovative targets for the development of more effective analgesics. We have previously demonstrated that neuronal pro-algogenic mediators upregulate G protein-coupled nucleotide P2Y receptors (P2YRs) expressed by TG SGCs in vitro. Here, we have identified the specific P2YR subtypes involved (i.e., the ADP-sensitive P2Y1 R and the UTP-responsive P2Y2 R subtypes), and demonstrated the contribution of neuron-derived prostaglandins to their upregulation. Next, we have translated these data to an in vivo model of TG pain (namely, rats injected with Complete Freund's adjuvant in the temporomandibular joint), by demonstrating activation of SGCs and upregulation of P2Y1 R and P2Y2 R in the ipsi-lateral TG. To unequivocally link P2YRs to the development of facial allodynia, we treated animals with various purinergic antagonists. The selective P2Y2 R antagonist AR-C118925 completely inhibited SGCs activation, exerted a potent anti-allodynic effect that lasted over time, and was still effective when administration was started 6-days post induction of allodynia, i.e. under subchronic pain conditions. Conversely, the selective P2Y1 R antagonist MRS2179 was completely ineffective. Moreover, similarly to the anti-inflammatory drug acetylsalicylic acid and the known anti-migraine agent sumatriptan, the P2X/P2Y nonselective antagonist PPADS was only partially effective, and completely lost its activity under sub-chronic conditions. Taken together, our results highlight glial P2Y2 Rs as potential "druggable" targets for the successful management of TG-related pain.
Collapse
Affiliation(s)
- Giulia Magni
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological and Biomolecular Sciences, Università Degli Studi Di Milano, via Balzaretti, 9, Milan, Italy; Department of Drug Discovery and Development, Italian Institute of Technology (IIT), via Morego, 30, Genoa, Italy
| | | | | | | | | |
Collapse
|
9
|
Cui J, He W, Yi B, Zhao H, Lu K, Ruan H, Ma D. mTOR pathway is involved in ADP-evoked astrocyte activation and ATP release in the spinal dorsal horn in a rat neuropathic pain model. Neuroscience 2014; 275:395-403. [PMID: 24976516 DOI: 10.1016/j.neuroscience.2014.06.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/10/2014] [Accepted: 06/13/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND ATP/ADP-evoked spinal astrocyte activation plays a vital role in the development of neuropathic pain. We aim to investigate the role of mammalian target of rapamycin (mTOR) pathway on the spinal astrocyte activation in the neuropathic pain development in rats. METHODS Sprague Dawley (SD) rats were subjected to chronic constriction of the sciatic nerve (CCI). Rapamycin or ADP was intrathecally injected daily to explore their effects on spinal astrocyte activation and pain development. Expression of glial fibrillary acidic protein (GFAP) and mTOR in the spinal dorsal horn was assessed by immunohistochemistry. Von Frey hairs and Hargreaves paw withdrawal test were conducted to evaluate mechanical allodynia and thermal sensitivity, respectively. Firefly luciferase ATP assay was used to assess the change of ATP level in cerebrospinal fluid (CSF) and medium of cultured astrocytes. RESULTS GFAP expression was enhanced in the ipsilateral spinal dorsal horn from day 3 after surgery. GFAP and mTOR expression in the rat spinal dorsal horn on post-surgical day 14 was enhanced by daily intrathecal injection of ADP, which was inhibited by rapamycin. Rapamycin decreased lower mechanical pain threshold and the thermal withdrawal latency. Intrathecal injection of ADP enhanced the ATP release, which was partially inhibited by rapamycin. Study of cultured astrocytes indicated that ATP could be released from astrocytes. CONCLUSION Our data demonstrated that ADP enhanced neuropathic pain in CCI rats, which was inhibited by rapamycin. This study indicates that targeting mTOR pathway could serve as a novel therapeutic strategy in neuropathic pain management.
Collapse
Affiliation(s)
- J Cui
- Department of Anaesthesiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - W He
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - B Yi
- Department of Anaesthesiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - H Zhao
- Section of Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
| | - K Lu
- Department of Anaesthesiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
| | - H Ruan
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China.
| | - D Ma
- Section of Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
| |
Collapse
|
10
|
Lin J, Wang C, Redies C. Restricted expression of classic cadherins in the spinal cord of the chicken embryo. Front Neuroanat 2014; 8:18. [PMID: 24744704 PMCID: PMC3978366 DOI: 10.3389/fnana.2014.00018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 03/12/2014] [Indexed: 01/12/2023] Open
Abstract
Classic cadherins belong to the family of cadherin genes and play important roles in neurogenesis, neuron migration, and axon growth. In the present study, we compared the expression patterns of 10 classic cadherins (Cdh2, Cdh4, Cdh6, Cdh7, Cdh8, Cdh9, Cdh11, Cdh12, Cdh18, and Cdh20) in the developing chicken spinal cord (SP) by in situ hybridization. Our results indicate that each of the investigated cadherins exhibits a spatially restricted and temporally regulated pattern of expression. At early developmental stages (E2.5–E3), Cdh2 is expressed throughout the neuroepithelial layer. Cdh6 is strongly positive in the roof plate and later also in the floor plate. Cdh7, Cdh11, Cdh12, and Cdh20 are expressed in restricted regions of the basal plate of the SP. At intermediate stages of development (E4–E10), specific expression profiles are observed for all investigated cadherins in the differentiating mantle layer along the dorsoventral, mediolateral, and rostrocaudal dimensions. Expression profiles are especially diverse for Cdh2, Cdh4, Cdh8, Cdh11, and Cdh20 in the dorsal horn, while different pools of motor neurons exhibit signal for Cdh6, Cdh7, Cdh8, Cdh9, Cdh12, and Cdh20 in the ventral horn. Interestingly, subpopulations of cells in the dorsal root ganglion express combinations of different cadherins. In the surrounding tissues, such as the boundary cap cells and the notochord, the cadherins are also expressed differentially. The highly regulated spatiotemporal expression patterns of the classic cadherins indicate that these genes potentially play multiple and diverse roles during the development of the SP and its surrounding tissues.
Collapse
Affiliation(s)
- Juntang Lin
- Institute of Anatomy I, University of Jena School of Medicine - Jena University Hospital Jena, Germany ; Xinxiang Medical University Xinxiang, Henan, China
| | - Congrui Wang
- Institute of Anatomy I, University of Jena School of Medicine - Jena University Hospital Jena, Germany ; Xinxiang Medical University Xinxiang, Henan, China
| | - Christoph Redies
- Institute of Anatomy I, University of Jena School of Medicine - Jena University Hospital Jena, Germany
| |
Collapse
|
11
|
T-type channel-mediated neurotransmitter release. Pflugers Arch 2014; 466:677-87. [PMID: 24595475 DOI: 10.1007/s00424-014-1489-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 02/18/2014] [Indexed: 10/25/2022]
Abstract
Besides controlling a wide variety of cell functions, T-type channels have been shown to regulate neurotransmitter release in peripheral and central synapses and neuroendocrine cells. Growing evidence over the last 10 years suggests a key role of Cav3.2 and Cav3.1 channels in controlling basal neurosecretion near resting conditions and sustained release during mild stimulations. In some cases, the contribution of low-voltage-activated (LVA) channels is not directly evident but requires either the activation of coupled presynaptic receptors, block of ion channels, or chelation of metal ions. Concerning the coupling to the secretory machinery, T-type channels appear loosely coupled to neurotransmitter and hormone release. In neurons, Cav3.2 and Cav3.1 channels mainly control the asynchronous appearance of "minis" [miniature inhibitory postsynaptic currents (mIPSCs) and miniature excitatory postsynaptic currents (mEPSCs)]. The same loose coupling is evident from membrane capacity and amperometric recordings in chromaffin cells and melanotropes where the low-threshold-driven exocytosis possesses the same linear Ca(2+) dependence of the other voltage-gated Ca(2+) channels (Cav1 and Cav2) that is strongly attenuated by slow calcium buffers. The intriguing issue is that, despite not expressing a consensus "synprint" site, Cav3.2 channels do interact with syntaxin 1A and SNAP-25 and, thus, may form nanodomains with secretory vesicles that can be regulated at low voltages. In this review, we discuss all the past and recent issues related to T-type channel-secretion coupling in neurons and neuroendocrine cells.
Collapse
|
12
|
Rozanski GM, Nath AR, Adams ME, Stanley EF. Low voltage-activated calcium channels gate transmitter release at the dorsal root ganglion sandwich synapse. J Physiol 2013; 591:5575-83. [PMID: 24000176 DOI: 10.1113/jphysiol.2013.260281] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A subpopulation of dorsal root ganglion (DRG) neurons are intimately attached in pairs and separated solely by thin satellite glial cell membrane septa. Stimulation of one neuron leads to transglial activation of its pair by a bi-, purinergic/glutamatergic synaptic pathway, a transmission mechanism that we term sandwich synapse (SS) transmission. Release of ATP from the stimulated neuron can be attributed to a classical mechanism involving Ca(2+) entry via voltage-gated calcium channels (CaV) but via an unknown channel type. Specific blockers and toxins ruled out CaV1, 2.1 and 2.2. Transmission was, however, blocked by a moderate depolarization (-50 mV) or low-concentration Ni(2+) (0.1 mM). Transmission persisted using a voltage pulse to -40 mV from a holding potential of -80 mV, confirming the involvement of a low voltage-activated channel type and limiting the candidate channel type to either CaV3.2 or a subpopulation of inactivation- and Ni(2+)-sensitive CaV2.3 channels. Resistance of the neuron calcium current and SS transmission to SNX482 argue against the latter. Hence, we conclude that inter-somatic transmission at the DRG SS is gated by CaV3.2 type calcium channels. The use of CaV3 family channels to gate transmission has important implications for the biological function of the DRG SS as information transfer would be predicted to occur not only in response to action potentials but also to sub-threshold membrane voltage oscillations. Thus, the SS synapse may serve as a homeostatic signalling mechanism between select neurons in the DRG and could play a role in abnormal sensation such as neuropathic pain.
Collapse
Affiliation(s)
- Gabriela M Rozanski
- E. F. Stanley: Canada Research Chair in Molecular Brain Science, MP 14-320, Toronto Western Research Institute, 399 Bathurst Street, Toronto ON M5T 2S8, Canada.
| | | | | | | |
Collapse
|