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Cristofori-Armstrong B, Budusan E, Rash LD. Mambalgin-3 potentiates human acid-sensing ion channel 1b under mild to moderate acidosis: Implications as an analgesic lead. Proc Natl Acad Sci U S A 2021; 118:e2021581118. [PMID: 33602819 DOI: 10.1073/pnas.2021581118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are expressed in the nervous system, activated by acidosis, and implicated in pain pathways. Mambalgins are peptide inhibitors of ASIC1 and analgesic in rodents via inhibition of centrally expressed ASIC1a and peripheral ASIC1b. This activity has generated interest in mambalgins as potential therapeutics. However, most mechanism and structure–activity relationship work on mambalgins has focused on ASIC1a, and neglected the peripheral analgesic target ASIC1b. Here, we compare mambalgin potency and mechanism of action at heterologously expressed rat and human ASIC1 variants. Unlike the nanomolar inhibition at ASIC1a and rodent ASIC1b, we find mambalgin-3 only weakly inhibits human ASIC1b and ASIC1b/3 under severe acidosis, but potentiates currents under mild/moderate acidosis. Our data highlight the importance of understanding the activity of potential ASIC-targeting pharmaceuticals at human channels.
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Ducrocq GP, Kim JS, Estrada JA, Kaufman MP. ASIC1a plays a key role in evoking the metabolic component of the exercise pressor reflex in rats. Am J Physiol Heart Circ Physiol 2020; 318:H78-H89. [PMID: 31675256 PMCID: PMC6985806 DOI: 10.1152/ajpheart.00565.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/23/2019] [Accepted: 10/28/2019] [Indexed: 11/22/2022]
Abstract
The role of the acid-sensing ion channel 1a (ASIC1a) in evoking the exercise pressor reflex is unknown, despite the fact that ASIC1a is opened by decreases in pH in the physiological range. This fact prompted us to test the hypothesis that ASIC1a plays an important role in evoking the exercise pressor reflex in decerebrated rats with freely perfused hindlimb muscles. To test this hypothesis, we measured the effect of injecting two ASIC1a blockers into the arterial supply of the triceps surae muscles on the reflex pressor responses to four maneuvers, namely 1) static contraction of the triceps surae muscles (i.e., the exercise pressor reflex), 2) calcaneal tendon stretch, 3) intra-arterial injection of lactic acid, and 4) intra-arterial injection of diprotonated phosphate. We found that the 2 ASIC1a blockers, psalmotoxin-1 (200 ng/kg) and mambalgin-1 (6.5 μg/kg), decreased the pressor responses to static contraction as well as the peak pressor responses to injection of lactic acid and diprotonated phosphate. In contrast, neither ASIC1a blocker had any effect on the pressor responses to tendon stretch. Importantly, we found that ASIC1a blockade significantly decreased the pressor response to static contraction after a latency of at least 8 s. Our results support the hypothesis that ASIC1a plays a key role in evoking the metabolic component of the exercise pressor reflex.NEW & NOTEWORTHY The role played by acid-sensing ion channel 1a (ASIC1a) in evoking the exercise pressor reflex remains unknown. In decerebrated rats with freely perfused femoral arteries, blocking ASIC1a with psalmotoxin-1 or mambalgin-1 significantly attenuated the pressor response to static contraction, lactic acid, and diprotonated phosphate injection but had no effect on the pressor response to stretch. We conclude that ASIC1a plays a key role in evoking the exercise pressor reflex by responding to contraction-induced metabolites, such as protons.
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Affiliation(s)
- Guillaume P Ducrocq
- Heart and Vascular Institute, Penn State College of Medicine, Hershey, Pennsylvania
| | - Joyce S Kim
- Heart and Vascular Institute, Penn State College of Medicine, Hershey, Pennsylvania
| | - Juan A Estrada
- Heart and Vascular Institute, Penn State College of Medicine, Hershey, Pennsylvania
| | - Marc P Kaufman
- Heart and Vascular Institute, Penn State College of Medicine, Hershey, Pennsylvania
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Mourier G, Salinas M, Kessler P, Stura EA, Leblanc M, Tepshi L, Besson T, Diochot S, Baron A, Douguet D, Lingueglia E, Servent D. Mambalgin-1 Pain-relieving Peptide, Stepwise Solid-phase Synthesis, Crystal Structure, and Functional Domain for Acid-sensing Ion Channel 1a Inhibition. J Biol Chem 2015; 291:2616-29. [PMID: 26680001 DOI: 10.1074/jbc.m115.702373] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [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: 11/10/2015] [Indexed: 01/04/2023] Open
Abstract
Mambalgins are peptides isolated from mamba venom that specifically inhibit a set of acid-sensing ion channels (ASICs) to relieve pain. We show here the first full stepwise solid phase peptide synthesis of mambalgin-1 and confirm the biological activity of the synthetic toxin both in vitro and in vivo. We also report the determination of its three-dimensional crystal structure showing differences with previously described NMR structures. Finally, the functional domain by which the toxin inhibits ASIC1a channels was identified in its loop II and more precisely in the face containing Phe-27, Leu-32, and Leu-34 residues. Moreover, proximity between Leu-32 in mambalgin-1 and Phe-350 in rASIC1a was proposed from double mutant cycle analysis. These data provide information on the structure and on the pharmacophore for ASIC channel inhibition by mambalgins that could have therapeutic value against pain and probably other neurological disorders.
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Affiliation(s)
- Gilles Mourier
- From the Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette
| | - Miguel Salinas
- the CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, the Université de Nice Sophia Antipolis, and the LabEx Ion Channel Science and Therapeutics, UMR 7275, 06560 Valbonne, France
| | - Pascal Kessler
- From the Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette
| | - Enrico A Stura
- From the Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette
| | - Mathieu Leblanc
- From the Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette
| | - Livia Tepshi
- From the Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette
| | - Thomas Besson
- the CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, the Université de Nice Sophia Antipolis, and the LabEx Ion Channel Science and Therapeutics, UMR 7275, 06560 Valbonne, France
| | - Sylvie Diochot
- the CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, the Université de Nice Sophia Antipolis, and the LabEx Ion Channel Science and Therapeutics, UMR 7275, 06560 Valbonne, France
| | - Anne Baron
- the CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, the Université de Nice Sophia Antipolis, and the LabEx Ion Channel Science and Therapeutics, UMR 7275, 06560 Valbonne, France
| | - Dominique Douguet
- the CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, the Université de Nice Sophia Antipolis, and
| | - Eric Lingueglia
- the CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, the Université de Nice Sophia Antipolis, and the LabEx Ion Channel Science and Therapeutics, UMR 7275, 06560 Valbonne, France
| | - Denis Servent
- From the Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette,
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