The Transient Receptor Potential Channel Antagonist SKF96365 is a Potent Blocker of Low-voltage-activated T-type Calcium Channels

Overview

Journal Br J Pharmacol

Publisher Wiley

Specialty Pharmacology

Date 2010 Jul 2

PMID 20590636

Citations 81

Authors

A Singh

M E Hildebrand

E Garcia

T P Snutch

Affiliations

Soon will be listed here.

Abstract

Background And Purpose: SKF96365 (SKF), originally identified as a blocker of receptor-mediated calcium entry, is widely used diagnostically, as a blocker of transient receptor potential canonical type (TRPC) channels. While SKF has been used as a tool to define the functional roles of TRPC channels in various cell and tissue types, there are notable overlapping physiological and pathophysiological associations between TRPC channels and low-voltage-activated (LVA) T-type calcium channels. The activity of SKF against T-type Ca channels has not been previously explored, and here we systematically investigated the effects of SKF on recombinant and native voltage-gated Ca channel-mediated currents.

Experimental Approach: Effects of SKF on recombinant Ca channels were studied under whole-cell patch clamp conditions after expression in HEK293 cells. The effect of SKF on cerebellar Purkinje cells (PCs) expressing native T-type Ca channels was also assessed.

Key Results: SKF blocked recombinant Ca channels, representative of each of the three main molecular genetic classes (Ca(V)1, Ca(V)2 and Ca(V)3) at concentrations typically utilized to assay TRPC function (10 microM). Particularly, human Ca(V)3.1 T-type Ca channels were more potently inhibited by SKF (IC(50) approximately 560 nM) in our experiments than previously reported for similarly expressed TRPC channels. SKF also inhibited native Ca(V)3.1 T-type currents in a rat cerebellar PC slice preparation.

Conclusions And Implications: SKF was a potent blocker of LVA T-type Ca channels. We suggest caution in the interpretation of results using SKF alone as a diagnostic agent for TRPC activity in native tissues.

Citing Articles

Ca transients on the T cell surface trigger rapid integrin activation in a timescale of seconds.

Li Y, Wang S, Zhang Y, Liu Z, Zheng Y, Zhang K Nat Commun. 2024; 15(1):6131.

PMID: 39033133 PMC: 11271479. DOI: 10.1038/s41467-024-50464-0.

A novel transient receptor potential C3/C6 selective activator induces the cellular uptake of antisense oligonucleotides.

Kohashi H, Nagata R, Tamenori Y, Amatani T, Ueda Y, Mori Y Nucleic Acids Res. 2024; 52(9):4784-4798.

PMID: 38621757 PMC: 11109983. DOI: 10.1093/nar/gkae245.

Side-by-side comparison of published small molecule inhibitors against thapsigargin-induced store-operated Ca2+ entry in HEK293 cells.

Norman K, Hemmings K, Shawer H, Appleby H, Burnett A, Hamzah N PLoS One. 2024; 19(1):e0296065.

PMID: 38261554 PMC: 10805320. DOI: 10.1371/journal.pone.0296065.

Store-Operated Calcium Entry Increases Nuclear Calcium in Adult Rat Atrial and Ventricular Cardiomyocytes.

Hermes J, Borisova V, Kockskamper J Cells. 2023; 12(23).

PMID: 38067118 PMC: 10705675. DOI: 10.3390/cells12232690.

Cell death induction and protection by activation of ubiquitously expressed anion/cation channels. Part 3: the roles and properties of TRPM2 and TRPM7.

Okada Y, Numata T, Sabirov R, Kashio M, Merzlyak P, Sato-Numata K Front Cell Dev Biol. 2023; 11:1246955.

PMID: 37842082 PMC: 10576435. DOI: 10.3389/fcell.2023.1246955.

References

Okada T, Shimizu S, Wakamori M, Maeda A, Kurosaki T, Takada N . Molecular cloning and functional characterization of a novel receptor-activated TRP Ca2+ channel from mouse brain. J Biol Chem. 1998; 273(17):10279-87. DOI: 10.1074/jbc.273.17.10279. View

Self D, Bian K, Mishra S, Hermsmeyer K . Stroke-prone SHR vascular muscle Ca2+ current amplitudes correlate with lethal increases in blood pressure. J Vasc Res. 1994; 31(6):359-66. DOI: 10.1159/000159064. View

Bannister R, Pessah I, Beam K . The skeletal L-type Ca(2+) current is a major contributor to excitation-coupled Ca(2+) entry. J Gen Physiol. 2008; 133(1):79-91. PMC: 2606935. DOI: 10.1085/jgp.200810105. View

Boulay G, Zhu X, Peyton M, Jiang M, Hurst R, Stefani E . Cloning and expression of a novel mammalian homolog of Drosophila transient receptor potential (Trp) involved in calcium entry secondary to activation of receptors coupled by the Gq class of G protein. J Biol Chem. 1997; 272(47):29672-80. DOI: 10.1074/jbc.272.47.29672. View

Orestes P, Bojadzic D, Chow R, Todorovic S . Mechanisms and functional significance of inhibition of neuronal T-type calcium channels by isoflurane. Mol Pharmacol. 2008; 75(3):542-54. PMC: 2645928. DOI: 10.1124/mol.108.051664. View

Doering C, Zamponi G . Molecular pharmacology of high voltage-activated calcium channels. J Bioenerg Biomembr. 2004; 35(6):491-505. DOI: 10.1023/b:jobb.0000008022.50702.1a. View

Chan J, Greenberg D . SK&F 96365, a receptor-mediated calcium entry inhibitor, inhibits calcium responses to endothelin-1 in NG108-15 cells. Biochem Biophys Res Commun. 1991; 177(3):1141-6. DOI: 10.1016/0006-291x(91)90658-t. View

Kiselyov K, Xu X, Mozhayeva G, Kuo T, Pessah I, Mignery G . Functional interaction between InsP3 receptors and store-operated Htrp3 channels. Nature. 1998; 396(6710):478-82. DOI: 10.1038/24890. View

Moran M, Xu H, Clapham D . TRP ion channels in the nervous system. Curr Opin Neurobiol. 2004; 14(3):362-9. DOI: 10.1016/j.conb.2004.05.003. View

10.

Hong S, Chang C . Inhibition of the Sodium Channel by SK&F 96365, an Inhibitor of the Receptor-Operated Calcium Channel, in Mouse Diaphragm. J Biomed Sci. 1994; 1(3):172-178. DOI: 10.1007/BF02253347. View

11.

Cui G, Okamoto T, Morikawa H . Spontaneous opening of T-type Ca2+ channels contributes to the irregular firing of dopamine neurons in neonatal rats. J Neurosci. 2004; 24(49):11079-87. PMC: 1454359. DOI: 10.1523/JNEUROSCI.2713-04.2004. View

12.

Hong S, Chang C . Facilitation of nicotinic receptor desensitization at mouse motor endplate by a receptor-operated Ca2+ channel blocker, SK&F 96365. Eur J Pharmacol. 1994; 265(1-2):35-42. DOI: 10.1016/0014-2999(94)90220-8. View

13.

Liu B, Freyer A, Hall I . Bradykinin activates calcium-dependent potassium channels in cultured human airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol. 2006; 292(4):L898-907. DOI: 10.1152/ajplung.00461.2005. View

14.

Barbara G, Alloui A, Nargeot J, Lory P, Eschalier A, Bourinet E . T-type calcium channel inhibition underlies the analgesic effects of the endogenous lipoamino acids. J Neurosci. 2009; 29(42):13106-14. PMC: 6665211. DOI: 10.1523/JNEUROSCI.2919-09.2009. View

15.

Rychkov G, Barritt G . TRPC1 Ca(2+)-permeable channels in animal cells. Handb Exp Pharmacol. 2007; (179):23-52. DOI: 10.1007/978-3-540-34891-7_2. View

16.

Meng F, To W, Gu Y . Role of TRP channels and NCX in mediating hypoxia-induced [Ca(2+)](i) elevation in PC12 cells. Respir Physiol Neurobiol. 2008; 164(3):386-93. DOI: 10.1016/j.resp.2008.09.002. View

17.

Davood A, Mansouri N, Rerza Dehpour A, Shafaroudi H, Alipour E, Shafiee A . Design, synthesis, and calcium channel antagonist activity of new 1,4-dihydropyridines containing 4-(5)-chloro-2-ethyl-5-(4)-imidazolyl substituent. Arch Pharm (Weinheim). 2006; 339(6):299-304. DOI: 10.1002/ardp.200600013. View

18.

Liu D, Yang D, He H, Chen X, Cao T, Feng X . Increased transient receptor potential canonical type 3 channels in vasculature from hypertensive rats. Hypertension. 2008; 53(1):70-6. DOI: 10.1161/HYPERTENSIONAHA.108.116947. View

19.

Schwarz G, Droogmans G, Nilius B . Multiple effects of SK&F 96365 on ionic currents and intracellular calcium in human endothelial cells. Cell Calcium. 1994; 15(1):45-54. DOI: 10.1016/0143-4160(94)90103-1. View

20.

Kim S, Kim Y, Yuan J, Petralia R, Worley P, Linden D . Activation of the TRPC1 cation channel by metabotropic glutamate receptor mGluR1. Nature. 2003; 426(6964):285-91. DOI: 10.1038/nature02162. View