Effect of non-steroidal anti-inflammatory drugs and new fenamate analogues on TRPC4 and TRPC5 channels

Jiang, Hongni; Zeng, Bo; Chen, Gui-Lan; Bot, David; Eastmond, Sarah; Elsenussi, Sandra E; Atkin, Stephen L; Boa, Andrew N; Xu, Shang-Zhong

Abstract

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used anti-inflammatory therapeutic agents,among which the fenamate analogues play important roles in regulating intracellular Ca²⁺ transient and ion channels. However, the effect of NSAIDs on TRPC4 and TRPC5 is still unknown. To understand thestructure–activity of fenamate analogues on TRPC channels, we have synthesized a series of fenamateanalogues and investigated their effects on TRPC4 and TRPC5 channels.Human TRPC4 and TRPC5 cDNAs in tetracycline-regulated vectors were transfected into HEK293T-REx cells. The whole cell current and Ca²⁺ movement were recorded by patch clamp and calciumimaging, respectively.Flufenamic acid (FFA), mefenamic acid (MFA), niflumic acid (NFA) and diclofenac sodium (DFS) showed inhibition on TRPC4 and TRPC5 channels in a concentration-dependent manner. The potencywas FFA > MFA > NFA > DFS. Modification of 2-phenylamino ring by substitution of the trifluoromethylgroup in FFA with –F, –CH₃, –OCH₃, –OCH₂CH₃, –COOH, and –NO2 led to the changes in their channelblocking activity. However, 2-(20-methoxy-50-methylphenyl)aminobenzoic acid stimulated TRPC4 andTRPC5 channels. Selective COX1-3 inhibitors (aspirin, celecoxib, acetaminophen, and indomethacin)had no effect on the channels. Longer perfusion (>5 min) with FFA (100 mM) and MFA (100 mM) caused apotentiation of TRPC4 and TRPC5 currents after their initial blocking effects that appeared to be partiallymediated by the mitochondrial Ca²⁺ release.Our results suggest that fenamate analogues are direct modulators of TRPC4 and TRPC5 channels. Thesubstitution pattern and conformation of the 2-phenylamino ring could alter their blocking activity,which is important for understanding fenamate pharmacology and new drug development targeting theTRPC channels.

Citation

Jiang, H., Zeng, B., Chen, G.-L., Bot, D., Eastmond, S., Elsenussi, S. E., Atkin, S. L., Boa, A. N., & Xu, S.-Z. (2012). Effect of non-steroidal anti-inflammatory drugs and new fenamate analogues on TRPC4 and TRPC5 channels. Biochemical Pharmacology, 83(7), 923-931. https://doi.org/10.1016/j.bcp.2012.01.014

• Journal Article Type: Article
• Acceptance Date: Jan 12, 2012
• Online Publication Date: Jan 20, 2012
• Publication Date: Apr 1, 2012
• Deposit Date: Nov 13, 2014
• Journal: Biochemical Pharmacology
• Print ISSN: 0006-2952
• Electronic ISSN: 1873-2968
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 83
• Issue: 7
• Pages: 923-931
• DOI: https://doi.org/10.1016/j.bcp.2012.01.014
• Keywords: Non-steroidal anti-inflammatory drugs, Calcium channel, TRPC, Fenamate analogues, 2-Aminoethoxydiphenyl borate, REF 2014 submission**
• Public URL: https://hull-repository.worktribe.com/output/466465
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0006295212000615?via%3Dihub
• Contract Date: Nov 13, 2014