title: The Poly(ADP-ribose) polymerase PARP-1 is required for oxidative stress-induced TRPM2 activation in lymphocytes.
abstract: TRPM2 cation channels are widely expressed in the immune system and are thought to play a role in immune cell responses to oxidative stress. Patch clamp analyses suggest that TRPM2 channel activation can occur through a direct action of oxidants on TRPM2 channels or indirectly through the actions of a related group of adenine nucleotide 2nd messengers. However, the contribution of each gating mechanism to oxidative stress-induced TRPM2 activation in lymphocytes remains undefined. To better understand the molecular events leading to TRPM2 activation in lymphocytes, we analyzed oxidative stress-induced turnover of intracellular NAD, the metabolic precursor of adenine nucleotide 2nd messengers implicated in TRPM2 gating, and oxidative stress-induced TRPM2-mediated currents and Ca2+ transients in DT40 B cells. TRPM2-dependent Ca2+ entry did not influence the extent or time course of oxidative stress-induced turnover of NAD. Furthermore, expression of oxidative stress-activated poly(ADP-ribose) polymerases (PARPs) was required for oxidative stress-induced NAD turnover, TRPM2 currents, and TRPM2-dependent Ca2+ transients; no oxidant-induced activation of TRPM2 channels could be detected in PARP-deficient cells. Together, our results suggest that during conditions of oxidative stress in lymphocytes, TRPM2 acts as a downstream effector of the PARP/poly(ADP-ribose) glycohydrolase pathway through PARP-dependent formation of ADP-ribose.
authors.affiliation: Department of Pediatrics and Immunology, University of Washington, Seattle, Washington 98103, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Buelow
authors.forename: Yumei
authors.initials: Y
authors.lastname: Song
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Scharenberg
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D009243:NAD / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016877:Oxidants / Q000276:immunology / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D018408:Patch-Clamp Techniques; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015290:Second Messenger Systems / Q000502:physiology*; D050053:TRPM Cation Channels / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D016877:Oxidants; D050053:TRPM Cation Channels; C121934:TRPM2 protein, human; D009243:NAD; D000246:Adenosine Diphosphate Ribose; C499320:PARP1 protein, human; C499321:Parp1 protein, mouse; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D002118:Calcium