TRPM2 channel opening in response to oxidative stress is dependent on activation of poly(ADP‐ribose) polymerase
- 1 September 2004
- journal article
- Published by Wiley in British Journal of Pharmacology
- Vol. 143 (1), 186-192
- https://doi.org/10.1038/sj.bjp.0705914
Abstract
1. TRPM2 (melastatin-like transient receptor potential 2 channel) is a nonselective cation channel that is activated under conditions of oxidative stress leading to an increase in intracellular free Ca(2+) concentration ([Ca(2+)](i)) and cell death. We investigated the role of the DNA repair enzyme poly(ADP-ribose) polymerase (PARP) on hydrogen peroxide (H(2)O(2))-mediated TRPM2 activation using a tetracycline-inducible TRPM2-expressing cell line. 2. In whole-cell patch-clamp recordings, intracellular adenine 5'-diphosphoribose (ADP-ribose) triggered an inward current in tetracycline-induced TRPM2-human embryonic kidney (HEK293) cells, but not in uninduced cells. Similarly, H(2)O(2) stimulated an increase in [Ca(2+)](i) (pEC(50) 4.54+/-0.02) in Fluo-4-loaded TRPM2-expressing HEK293 cells, but not in uninduced cells. Induction of TRPM2 expression caused an increase in susceptibility to plasma membrane damage and mitochondrial dysfunction in response to H(2)O(2). These data demonstrate functional expression of TRPM2 following tetracycline induction in TRPM2-HEK293 cells. 3. PARP inhibitors SB750139-B (patent number DE10039610-A1 (Lubisch et al., 2001)), PJ34 (N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-N,N-dimethylacetamide) and DPQ (3, 4-dihydro-5-[4-(1-piperidinyl)butoxy]-1(2H)-isoquinolinone) inhibited H(2)O(2)-mediated increases in [Ca(2+)](i) (pIC(50) vs 100 microm H(2)O(2): 7.64+/-0.38; 6.68+/-0.28; 4.78+/-0.05, respectively), increases in mitochondrial dysfunction (pIC(50) vs 300 microm H(2)O(2): 7.32+/-0.23; 6.69+/-0.22; 5.44+/-0.09, respectively) and decreases in plasma membrane integrity (pIC(50) vs 300 microm H(2)O(2): 7.45+/-0.27; 6.35+/-0.18; 5.29+/-0.12, respectively). The order of potency of the PARP inhibitors in these assays (SB750139>PJ34>DPQ) was the same as for inhibition of isolated PARP enzyme. 4. SB750139-B, PJ34 and DPQ had no effect on inward currents elicited by intracellular ADP-ribose in tetracycline-induced TRPM2-HEK293 cells, suggesting that PARP inhibitors are not interacting directly with the channel. 5. SB750139-B, PJ34 and DPQ inhibited increases in [Ca(2+)](i) in a rat insulinoma cell line (CRI-G1 cells) endogenously expressing TRPM2 (pIC(50) vs 100 microm H(2)O(2): 7.64+/-0.38; 6.68+/-0.28; 4.78+/-0.05, respectively). 6. These data suggest that oxidative stress causes TRPM2 channel opening in both recombinant and endogenously expressing cell systems via activation of PARP enzymes.Keywords
This publication has 23 references indexed in Scilit:
- A Novel TRPM2 Isoform Inhibits Calcium Influx and Susceptibility to Cell DeathOnline Journal of Public Health Informatics, 2003
- Critical Intracellular Ca2+ Dependence of Transient Receptor Potential Melastatin 2 (TRPM2) Cation Channel ActivationJournal of Biological Chemistry, 2003
- The Therapeutic Potential of Poly(ADP-Ribose) Polymerase InhibitorsPharmacological Reviews, 2002
- New inhibitors of poly(ADP-ribose) polymerase and their potential therapeutic targetsExpert Opinion on Therapeutic Patents, 2002
- Activation of the Cation Channel Long Transient Receptor Potential Channel 2 (LTRPC2) by Hydrogen PeroxideJournal of Biological Chemistry, 2002
- Immunocyte Ca 2+ Influx System Mediated by LTRPC2Science, 2001
- The world according to PARPTrends in Biochemical Sciences, 2001
- Molecular Cloning of a Novel Putative Ca2+Channel Protein (TRPC7) Highly Expressed in BrainGenomics, 1998
- Neuroprotective Effects of Inhibiting Poly(ADP-Ribose) Synthetase on Focal Cerebral Ischemia in RatsJournal of Cerebral Blood Flow & Metabolism, 1997
- Poly(ADP-ribose) polymerase: a molecular nick-sensorTrends in Biochemical Sciences, 1994