TY - JOUR
T1 - Inhibition of human N- and T-type calcium channels by an ortho-phenoxyanilide derivative, MONIRO-1
AU - McArthur, Jeffrey R
AU - Motin, Leonid
AU - Gleeson, Ellen C
AU - Spiller, Sandro
AU - Lewis, Richard J
AU - Duggan, Peter J
AU - Tuck, Kellie L
AU - Adams, David J
PY - 2018/6
Y1 - 2018/6
N2 - Background and Purpose: Voltage-gated calcium channels are involved in nociception in the CNS and in the periphery. N-type (Ca v 2.2) and T-type (Ca v 3.1, Ca v 3.2 and Ca v 3.3) voltage-gated calcium channels are particularly important in studying and treating pain and epilepsy. Experimental Approach: In this study, whole-cell patch clamp electrophysiology was used to assess the potency and mechanism of action of a novel ortho-phenoxylanilide derivative, MONIRO-1, against a panel of voltage-gated calcium channels including Ca v 1.2, Ca v 1.3, Ca v 2.1, Ca v 2.2, Ca v 2.3, Ca v 3.1, Ca v 3.2 and Ca v 3.3. Key Results: MONIRO-1 was 5- to 20-fold more potent at inhibiting human T-type calcium channels, hCa v 3.1, hCa v 3.2 and hCa v 3.3 (IC 50 : 3.3 ± 0.3, 1.7 ± 0.1 and 7.2 ± 0.3 μM, respectively) than N-type calcium channel, hCa v 2.2 (IC 50 : 34.0 ± 3.6 μM). It interacted with L-type calcium channels Ca v 1.2 and Ca v 1.3 with significantly lower potency (IC 50 > 100 μM) and did not inhibit hCa v 2.1 or hCa v 2.3 channels at concentrations as high as 100 μM. State- and use-dependent inhibition of hCa v 2.2 channels was observed, whereas stronger inhibition occurred at high stimulation frequencies for hCa v 3.1 channels suggesting a different mode of action between these two channels. Conclusions and Implications: Selectivity, potency, reversibility and multi-modal effects distinguish MONIRO-1 from other low MW inhibitors acting on Ca v channels involved in pain and/or epilepsy pathways. High-frequency firing increased the affinity for MONIRO-1 for both hCa v 2.2 and hCa v 3.1 channels. Such Ca v channel modulators have potential clinical use in the treatment of epilepsies, neuropathic pain and other nociceptive pathophysiologies. Linked Articles: This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
AB - Background and Purpose: Voltage-gated calcium channels are involved in nociception in the CNS and in the periphery. N-type (Ca v 2.2) and T-type (Ca v 3.1, Ca v 3.2 and Ca v 3.3) voltage-gated calcium channels are particularly important in studying and treating pain and epilepsy. Experimental Approach: In this study, whole-cell patch clamp electrophysiology was used to assess the potency and mechanism of action of a novel ortho-phenoxylanilide derivative, MONIRO-1, against a panel of voltage-gated calcium channels including Ca v 1.2, Ca v 1.3, Ca v 2.1, Ca v 2.2, Ca v 2.3, Ca v 3.1, Ca v 3.2 and Ca v 3.3. Key Results: MONIRO-1 was 5- to 20-fold more potent at inhibiting human T-type calcium channels, hCa v 3.1, hCa v 3.2 and hCa v 3.3 (IC 50 : 3.3 ± 0.3, 1.7 ± 0.1 and 7.2 ± 0.3 μM, respectively) than N-type calcium channel, hCa v 2.2 (IC 50 : 34.0 ± 3.6 μM). It interacted with L-type calcium channels Ca v 1.2 and Ca v 1.3 with significantly lower potency (IC 50 > 100 μM) and did not inhibit hCa v 2.1 or hCa v 2.3 channels at concentrations as high as 100 μM. State- and use-dependent inhibition of hCa v 2.2 channels was observed, whereas stronger inhibition occurred at high stimulation frequencies for hCa v 3.1 channels suggesting a different mode of action between these two channels. Conclusions and Implications: Selectivity, potency, reversibility and multi-modal effects distinguish MONIRO-1 from other low MW inhibitors acting on Ca v channels involved in pain and/or epilepsy pathways. High-frequency firing increased the affinity for MONIRO-1 for both hCa v 2.2 and hCa v 3.1 channels. Such Ca v channel modulators have potential clinical use in the treatment of epilepsies, neuropathic pain and other nociceptive pathophysiologies. Linked Articles: This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
KW - Calcium channels
KW - Nociception and neurocircuits
KW - N-type calcium channel
KW - T-type calcium channel
KW - MONIRO-1
KW - ortho-phenoxyanilide
KW - Voltage-gated calcium channels
KW - hERG
UR - http://www.scopus.com/inward/record.url?scp=85047951872&partnerID=8YFLogxK
U2 - 10.1111/bph.13910
DO - 10.1111/bph.13910
M3 - Article
C2 - 28608537
AN - SCOPUS:85047951872
SN - 0007-1188
VL - 175
SP - 2284
EP - 2295
JO - British Journal of Pharmacology
JF - British Journal of Pharmacology
IS - 12
ER -