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Knutson KR, Whiteman ST, Alcaino C, Mercado-Perez A, Finholm I, Serlin HK, Bellampalli SS, Linden DR, Farrugia G, Beyder A. Intestinal enteroendocrine cells rely on ryanodine and IP 3 calcium store receptors for mechanotransduction. J Physiol 2023; 601:287-305. [PMID: 36428286 PMCID: PMC9840706 DOI: 10.1113/jp283383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 11/24/2022] [Indexed: 11/27/2022] Open
Abstract
Enteroendocrine cells (EECs) are specialized sensors of luminal forces and chemicals in the gastrointestinal (GI) epithelium that respond to stimulation with a release of signalling molecules such as serotonin (5-HT). For mechanosensitive EECs, force activates Piezo2 channels, which generate a very rapidly activating and inactivating (∼10 ms) cationic (Na+ , K+ , Ca2+ ) receptor current. Piezo2 receptor currents lead to a large and persistent increase in intracellular calcium (Ca2+ ) that lasts many seconds to sometimes minutes, suggesting signal amplification. However, intracellular calcium dynamics in EEC mechanotransduction remain poorly understood. The aim of this study was to determine the role of Ca2+ stores in EEC mechanotransduction. Mechanical stimulation of a human EEC cell model (QGP-1) resulted in a rapid increase in cytoplasmic Ca2+ and a slower decrease in ER stores Ca2+ , suggesting the involvement of intracellular Ca2+ stores. Comparing murine primary colonic EECs with colonocytes showed expression of intercellular Ca2+ store receptors, a similar expression of IP3 receptors, but a >30-fold enriched expression of Ryr3 in EECs. In mechanically stimulated primary EECs, Ca2+ responses decreased dramatically by emptying stores and pharmacologically blocking IP3 and RyR1/3 receptors. RyR3 genetic knockdown by siRNA led to a significant decrease in mechanosensitive Ca2+ responses and 5-HT release. In tissue, pressure-induced increase in the Ussing short circuit current was significantly decreased by ryanodine receptor blockade. Our data show that mechanosensitive EECs use intracellular Ca2+ stores to amplify mechanically induced Ca2+ entry, with RyR3 receptors selectively expressed in EECs and involved in Ca2+ signalling, 5-HT release and epithelial secretion. KEY POINTS: A population of enteroendocrine cells (EECs) are specialized mechanosensors of the gastrointestinal (GI) epithelium that respond to mechanical stimulation with the release of important signalling molecules such as serotonin. Mechanical activation of these EECs leads to an increase in intracellular calcium (Ca2+ ) with a longer duration than the stimulus, suggesting intracellular Ca2+ signal amplification. In this study, we profiled the expression of intracellular Ca2+ store receptors and found an enriched expression of the intracellular Ca2+ receptor Ryr3, which contributed to the mechanically evoked increases in intracellular calcium, 5-HT release and epithelial secretion. Our data suggest that mechanosensitive EECs rely on intracellular Ca2+ stores and are selective in their use of Ryr3 for amplification of intracellular Ca2+ . This work advances our understanding of EEC mechanotransduction and may provide novel diagnostic and therapeutic targets for GI motility disorders.
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Affiliation(s)
- Kaitlyn R. Knutson
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Sara T. Whiteman
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Constanza Alcaino
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Arnaldo Mercado-Perez
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
- Medical Scientist Training Program (MSTP), Mayo Clinic, Rochester, Minnesota
| | - Isabelle Finholm
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Hannah K. Serlin
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Shreya S. Bellampalli
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
- Medical Scientist Training Program (MSTP), Mayo Clinic, Rochester, Minnesota
| | - David R. Linden
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Gianrico Farrugia
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Division of Gastroenterology &Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Arthur Beyder
- Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, Minnesota
- Division of Gastroenterology &Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
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2
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Zhou Y, Cai S, Gomez K, Wijeratne EMK, Ji Y, Bellampalli SS, Luo S, Moutal A, Gunatilaka AAL, Khanna R. 1-O-Acetylgeopyxin A, a derivative of a fungal metabolite, blocks tetrodotoxin-sensitive voltage-gated sodium, calcium channels and neuronal excitability which correlates with inhibition of neuropathic pain. Mol Brain 2020; 13:73. [PMID: 32393368 PMCID: PMC7216607 DOI: 10.1186/s13041-020-00616-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 05/04/2020] [Indexed: 01/03/2023] Open
Abstract
Chronic pain can be the result of an underlying disease or condition, medical treatment, inflammation, or injury. The number of persons experiencing this type of pain is substantial, affecting upwards of 50 million adults in the United States. Pharmacotherapy of most of the severe chronic pain patients includes drugs such as gabapentinoids, re-uptake blockers and opioids. Unfortunately, gabapentinoids are not effective in up to two-thirds of this population and although opioids can be initially effective, their long-term use is associated with multiple side effects. Therefore, there is a great need to develop novel non-opioid alternative therapies to relieve chronic pain. For this purpose, we screened a small library of natural products and their derivatives in the search for pharmacological inhibitors of voltage-gated calcium and sodium channels, which are outstanding molecular targets due to their important roles in nociceptive pathways. We discovered that the acetylated derivative of the ent-kaurane diterpenoid, geopyxin A, 1-O-acetylgeopyxin A, blocks voltage-gated calcium and tetrodotoxin-sensitive voltage-gated sodium channels but not tetrodotoxin-resistant sodium channels in dorsal root ganglion (DRG) neurons. Consistent with inhibition of voltage-gated sodium and calcium channels, 1-O-acetylgeopyxin A reduced reduce action potential firing frequency and increased firing threshold (rheobase) in DRG neurons. Finally, we identified the potential of 1-O-acetylgeopyxin A to reverse mechanical allodynia in a preclinical rat model of HIV-induced sensory neuropathy. Dual targeting of both sodium and calcium channels may permit block of nociceptor excitability and of release of pro-nociceptive transmitters. Future studies will harness the core structure of geopyxins for the generation of antinociceptive drugs.
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Affiliation(s)
- Yuan Zhou
- Department of Clinical Laboratory, the First Hospital of Jilin University, Changchun, 130021, China
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - Song Cai
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - Kimberly Gomez
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - E M Kithsiri Wijeratne
- Southwest Center for Natural Products Research, School of Natural Resources & the Environment, College of Agriculture & Life Sciences, The University of Arizona, Tucson, AZ, 85724, USA
| | - Yingshi Ji
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - Shreya S Bellampalli
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - Shizhen Luo
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - Aubin Moutal
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - A A Leslie Gunatilaka
- Southwest Center for Natural Products Research, School of Natural Resources & the Environment, College of Agriculture & Life Sciences, The University of Arizona, Tucson, AZ, 85724, USA
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA.
- Neuroscience Graduate Interdisciplinary Program, College of Medicine, Tucson, AZ, 85724, USA.
- The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ, 85724, USA.
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3
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Bellampalli SS, Ji Y, Moutal A, Cai S, Wijeratne EMK, Gandini MA, Yu J, Chefdeville A, Dorame A, Chew LA, Madura CL, Luo S, Molnar G, Khanna M, Streicher JM, Zamponi GW, Gunatilaka AAL, Khanna R. Betulinic acid, derived from the desert lavender Hyptis emoryi, attenuates paclitaxel-, HIV-, and nerve injury-associated peripheral sensory neuropathy via block of N- and T-type calcium channels. Pain 2019; 160:117-135. [PMID: 30169422 DOI: 10.1097/j.pain.0000000000001385] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Federal Pain Research Strategy recommended development of nonopioid analgesics as a top priority in its strategic plan to address the significant public health crisis and individual burden of chronic pain faced by >100 million Americans. Motivated by this challenge, a natural product extracts library was screened and identified a plant extract that targets activity of voltage-gated calcium channels. This profile is of interest as a potential treatment for neuropathic pain. The active extract derived from the desert lavender plant native to southwestern United States, when subjected to bioassay-guided fractionation, afforded 3 compounds identified as pentacyclic triterpenoids, betulinic acid (BA), oleanolic acid, and ursolic acid. Betulinic acid inhibited depolarization-evoked calcium influx in dorsal root ganglion (DRG) neurons predominantly through targeting low-voltage-gated (Cav3 or T-type) and CaV2.2 (N-type) calcium channels. Voltage-clamp electrophysiology experiments revealed a reduction of Ca, but not Na, currents in sensory neurons after BA exposure. Betulinic acid inhibited spontaneous excitatory postsynaptic currents and depolarization-evoked release of calcitonin gene-related peptide from lumbar spinal cord slices. Notably, BA did not engage human mu, delta, or kappa opioid receptors. Intrathecal administration of BA reversed mechanical allodynia in rat models of chemotherapy-induced peripheral neuropathy and HIV-associated peripheral sensory neuropathy as well as a mouse model of partial sciatic nerve ligation without effects on locomotion. The broad-spectrum biological and medicinal properties reported, including anti-HIV and anticancer activities of BA and its derivatives, position this plant-derived small molecule natural product as a potential nonopioid therapy for management of chronic pain.
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Affiliation(s)
- Shreya S Bellampalli
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Yingshi Ji
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States.,Department of Pharmacology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin, People's Republic of China
| | - Aubin Moutal
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Song Cai
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - E M Kithsiri Wijeratne
- Natural Products Center, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, The University of Arizona, Tucson, AZ, United States
| | - Maria A Gandini
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jie Yu
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Aude Chefdeville
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Angie Dorame
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Lindsey A Chew
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Cynthia L Madura
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Shizhen Luo
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Gabriella Molnar
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - May Khanna
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States.,The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ, United States
| | - John M Streicher
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - A A Leslie Gunatilaka
- Natural Products Center, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, The University of Arizona, Tucson, AZ, United States
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States.,The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ, United States.,Department of Neuroscience Graduate Interdisciplinary Program, College of Medicine, The University of Arizona, Tucson, AZ, United States
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4
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Khanna R, Patwardhan A, Yang X, Li W, Cai S, Ji Y, Chew LA, Dorame A, Bellampalli SS, Schmoll RW, Gordon J, Moutal A, Vanderah TW, Porreca F, Ibrahim MM. Development and Characterization of An Injury-free Model of Functional Pain in Rats by Exposure to Red Light. J Pain 2019; 20:1293-1306. [PMID: 31054915 DOI: 10.1016/j.jpain.2019.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 02/23/2019] [Accepted: 04/15/2019] [Indexed: 12/19/2022]
Abstract
We report the development and characterization of a novel, injury-free rat model in which nociceptive sensitization after red light is observed in multiple body areas reminiscent of widespread pain in functional pain syndromes. Rats were exposed to red light-emitting diodes (RLED) (LEDs, 660 nm) at an intensity of 50 Lux for 8 hours daily for 5 days resulting in time- and dose-dependent thermal hyperalgesia and mechanical allodynia in both male and female rats. Females showed an earlier onset of mechanical allodynia than males. The pronociceptive effects of RLED were mediated through the visual system. RLED-induced thermal hyperalgesia and mechanical allodynia were reversed with medications commonly used for widespread pain, including gabapentin, tricyclic antidepressants, serotonin/norepinephrine reuptake inhibitors, and nonsteroidal anti-inflammatory drugs. Acetaminophen failed to reverse the RLED induced hypersensitivity. The hyperalgesic effects of RLED were blocked when bicuculline, a gamma-aminobutyric acid-A receptor antagonist, was administered into the rostral ventromedial medulla, suggesting a role for increased descending facilitation in the pain pathway. Key experiments were subjected to a replication study with randomization, investigator blinding, inclusion of all data, and high levels of statistical rigor. RLED-induced thermal hyperalgesia and mechanical allodynia without injury offers a novel injury-free rodent model useful for the study of functional pain syndromes with widespread pain. RLED exposure also emphasizes the different biological effects of different colors of light exposure. PERSPECTIVE: This study demonstrates the effect of light exposure on nociceptive thresholds. These biological effects of red LED add evidence to the emerging understanding of the biological effects of light of different colors in animals and humans. Understanding the underlying biology of red light-induced widespread pain may offer insights into functional pain states.
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Affiliation(s)
- Rajesh Khanna
- Department of Anesthesiology, University of Arizona, Tucson, Arizona; Department of Pharmacology, University of Arizona, Tucson, Arizona; Department of Graduate Interdisciplinary Program in Neuroscience College of Medicine, University of Arizona, Tucson, Arizona
| | - Amol Patwardhan
- Department of Anesthesiology, University of Arizona, Tucson, Arizona; Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Xiaofang Yang
- Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Wennan Li
- Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Song Cai
- Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Yingshi Ji
- Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Lindsey A Chew
- Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Angie Dorame
- Department of Pharmacology, University of Arizona, Tucson, Arizona
| | | | - Ryan W Schmoll
- Department of Anesthesiology, University of Arizona, Tucson, Arizona
| | - Janalee Gordon
- Department of Anesthesiology, University of Arizona, Tucson, Arizona
| | - Aubin Moutal
- Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Todd W Vanderah
- Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Frank Porreca
- Department of Anesthesiology, University of Arizona, Tucson, Arizona; Department of Pharmacology, University of Arizona, Tucson, Arizona
| | - Mohab M Ibrahim
- Department of Anesthesiology, University of Arizona, Tucson, Arizona; Department of Pharmacology, University of Arizona, Tucson, Arizona.
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5
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Cai S, Bellampalli SS, Yu J, Li W, Ji Y, Wijeratne EMK, Dorame A, Luo S, Shan Z, Khanna M, Moutal A, Streicher JM, Gunatilaka AAL, Khanna R. (-)-Hardwickiic Acid and Hautriwaic Acid Induce Antinociception via Blockade of Tetrodotoxin-Sensitive Voltage-Dependent Sodium Channels. ACS Chem Neurosci 2019; 10:1716-1728. [PMID: 30525440 DOI: 10.1021/acschemneuro.8b00617] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
For an affliction that debilitates an estimated 50 million adults in the United States, the current chronic pain management approaches are inadequate. The Centers for Disease Control and Prevention have called for a minimization in opioid prescription and use for chronic pain conditions, and thus, it is imperative to discover alternative non-opioid based strategies. For the realization of this call, a library of natural products was screened in search of pharmacological inhibitors of both voltage-gated calcium channels and voltage-gated sodium channels, which are excellent targets due to their well-established roles in nociceptive pathways. We discovered (-)-hardwickiic acid ((-)-HDA) and hautriwaic acid (HTA) isolated from plants, Croton californicus and Eremocarpus setigerus, respectively, inhibited tetrodotoxin-sensitive sodium, but not calcium or potassium, channels in small diameter, presumptively nociceptive, dorsal root ganglion (DRG) neurons. Failure to inhibit spontaneous postsynaptic excitatory currents indicated a preferential targeting of voltage-gated sodium channels over voltage-gated calcium channels by these extracts. Neither compound was a ligand at opioid receptors. Finally, we identified the potential of both (-)-HDA and HTA to reverse chronic pain behavior in preclinical rat models of HIV-sensory neuropathy, and for (-)-HDA specifically, in chemotherapy-induced peripheral neuropathy. Our results illustrate the therapeutic potential for (-)-HDA and HTA for chronic pain management and could represent a scaffold, that, if optimized by structure-activity relationship studies, may yield novel specific sodium channel antagonists for pain relief.
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Affiliation(s)
| | | | - Jie Yu
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou 310058, P.R. China
| | | | - Yingshi Ji
- Department of Pharmacology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | | | | | | | - Zhiming Shan
- Department of Anesthesiology, Shenzhen People’s Hospital & Second Clinical Medical College of Jinan University, Shenzhen 518020, P.R. China
| | - May Khanna
- The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, Arizona 85724, United States
| | | | | | | | - Rajesh Khanna
- The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, Arizona 85724, United States
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6
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Chew LA, Bellampalli SS, Dustrude ET, Khanna R. Mining the Na v1.7 interactome: Opportunities for chronic pain therapeutics. Biochem Pharmacol 2019; 163:9-20. [PMID: 30699328 DOI: 10.1016/j.bcp.2019.01.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/24/2019] [Indexed: 12/14/2022]
Abstract
The peripherally expressed voltage-gated sodium NaV1.7 (gene SCN9A) channel boosts small stimuli to initiate firing of pain-signaling dorsal root ganglia (DRG) neurons and facilitates neurotransmitter release at the first synapse within the spinal cord. Mutations in SCN9A produce distinct human pain syndromes. Widely acknowledged as a "gatekeeper" of pain, NaV1.7 has been the focus of intense investigation but, to date, no NaV1.7-selective drugs have reached the clinic. Elegant crystallographic studies have demonstrated the potential of designing highly potent and selective NaV1.7 compounds but their therapeutic value remains untested. Transcriptional silencing of NaV1.7 by a naturally expressed antisense transcript has been reported in rodents and humans but whether this represents a viable opportunity for designing NaV1.7 therapeutics is currently unknown. The demonstration that loss of NaV1.7 function is associated with upregulation of endogenous opioids and potentiation of mu- and delta-opioid receptor activities, suggests that targeting only NaV1.7 may be insufficient for analgesia. However, the link between opioid-dependent analgesic mechanisms and function of sodium channels and intracellular sodium-dependent signaling remains controversial. Thus, additional new targets - regulators, modulators - are needed. In this context, we mine the literature for the known interactome of NaV1.7 with a focus on protein interactors that affect the channel's trafficking or link it to opioid signaling. As a case study, we present antinociceptive evidence of allosteric regulation of NaV1.7 by the cytosolic collapsin response mediator protein 2 (CRMP2). Throughout discussions of these possible new targets, we offer thoughts on the therapeutic implications of modulating NaV1.7 function in chronic pain.
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Affiliation(s)
- Lindsey A Chew
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
| | - Shreya S Bellampalli
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
| | - Erik T Dustrude
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA; Graduate Interdisciplinary Program in Neuroscience, College of Medicine, University of Arizona, Tucson, AZ, USA; The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ 85724, USA.
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7
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White KA, Swier VJ, Cain JT, Kohlmeyer JL, Meyerholz DK, Tanas MR, Uthoff J, Hammond E, Li H, Rohret FA, Goeken A, Chan CH, Leidinger MR, Umesalma S, Wallace MR, Dodd RD, Panzer K, Tang AH, Darbro BW, Moutal A, Cai S, Li W, Bellampalli SS, Khanna R, Rogers CS, Sieren JC, Quelle DE, Weimer JM. A porcine model of neurofibromatosis type 1 that mimics the human disease. JCI Insight 2018; 3:120402. [PMID: 29925695 DOI: 10.1172/jci.insight.120402] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/17/2018] [Indexed: 12/11/2022] Open
Abstract
Loss of the NF1 tumor suppressor gene causes the autosomal dominant condition, neurofibromatosis type 1 (NF1). Children and adults with NF1 suffer from pathologies including benign and malignant tumors to cognitive deficits, seizures, growth abnormalities, and peripheral neuropathies. NF1 encodes neurofibromin, a Ras-GTPase activating protein, and NF1 mutations result in hyperactivated Ras signaling in patients. Existing NF1 mutant mice mimic individual aspects of NF1, but none comprehensively models the disease. We describe a potentially novel Yucatan miniswine model bearing a heterozygotic mutation in NF1 (exon 42 deletion) orthologous to a mutation found in NF1 patients. NF1+/ex42del miniswine phenocopy the wide range of manifestations seen in NF1 patients, including café au lait spots, neurofibromas, axillary freckling, and neurological defects in learning and memory. Molecular analyses verified reduced neurofibromin expression in swine NF1+/ex42del fibroblasts, as well as hyperactivation of Ras, as measured by increased expression of its downstream effectors, phosphorylated ERK1/2, SIAH, and the checkpoint regulators p53 and p21. Consistent with altered pain signaling in NF1, dysregulation of calcium and sodium channels was observed in dorsal root ganglia expressing mutant NF1. Thus, these NF1+/ex42del miniswine recapitulate the disease and provide a unique, much-needed tool to advance the study and treatment of NF1.
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Affiliation(s)
- Katherine A White
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
| | - Vicki J Swier
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
| | - Jacob T Cain
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
| | | | | | | | - Johanna Uthoff
- Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Department of Biomedical Engineering at the University of Iowa, Iowa City, Iowa, USA
| | - Emily Hammond
- Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Department of Biomedical Engineering at the University of Iowa, Iowa City, Iowa, USA
| | - Hua Li
- Department of Molecular Genetics and Microbiology and.,University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, USA
| | | | | | - Chun-Hung Chan
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
| | | | | | - Margaret R Wallace
- Department of Molecular Genetics and Microbiology and.,University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, USA
| | - Rebecca D Dodd
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, USA
| | - Karin Panzer
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Amy H Tang
- Department of Microbiology and Molecular Cell Biology, Leroy T. Canoles Jr. Cancer Research Center, Eastern Virginia Medical School, Norfolk, Virginia
| | - Benjamin W Darbro
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, USA.,Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Aubin Moutal
- Department of Pharmacology, University of Arizona, Tucson, Arizona, USA
| | - Song Cai
- Department of Pharmacology, University of Arizona, Tucson, Arizona, USA
| | - Wennan Li
- Department of Pharmacology, University of Arizona, Tucson, Arizona, USA
| | | | - Rajesh Khanna
- Department of Pharmacology, University of Arizona, Tucson, Arizona, USA
| | | | - Jessica C Sieren
- Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Department of Biomedical Engineering at the University of Iowa, Iowa City, Iowa, USA.,Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, USA
| | - Dawn E Quelle
- Molecular Medicine Program.,Department of Pathology, and.,Department of Pharmacology and.,Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, USA
| | - Jill M Weimer
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA.,Department of Pediatrics, Sanford School of Medicine at the University of South Dakota, Sioux Falls, South Dakota, USA
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