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., Bot, D., Eastmond, S., Elsenussi, S. E., …Xu, S. (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
• 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