title: NAD+ levels control Ca2+ store replenishment and mitogen-induced increase of cytosolic Ca2+ by Cyclic ADP-ribose-dependent TRPM2 channel gating in human T lymphocytes.
abstract: Intracellular NAD(+) levels ([NAD(+)](i)) are important in regulating human T lymphocyte survival, cytokine secretion, and the capacity to respond to antigenic stimuli. NAD(+)-derived Ca(2+)-mobilizing second messengers, produced by CD38, play a pivotal role in T cell activation. Here we demonstrate that [NAD(+)](i) modifications in T lymphocytes affect intracellular Ca(2+) homeostasis both in terms of mitogen-induced [Ca(2+)](i) increase and of endoplasmic reticulum Ca(2+) store replenishment. Lowering [NAD(+)](i) by FK866-mediated nicotinamide phosphoribosyltransferase inhibition decreased the mitogen-induced [Ca(2+)](i) rise in Jurkat cells and in activated T lymphocytes. Accordingly, the Ca(2+) content of thapsigargin-sensitive Ca(2+) stores was greatly reduced in these cells in the presence of FK866. When NAD(+) levels were increased by supplementing peripheral blood lymphocytes with the NAD(+) precursors nicotinamide, nicotinic acid, or nicotinamide mononucleotide, the Ca(2+) content of thapsigargin-sensitive Ca(2+) stores as well as cell responsiveness to mitogens in terms of [Ca(2+)](i) elevation were up-regulated. The use of specific siRNA showed that the changes of Ca(2+) homeostasis induced by NAD(+) precursors are mediated by CD38 and the consequent ADPR-mediated TRPM2 gating. Finally, the presence of NAD(+) precursors up-regulated important T cell functions, such as proliferation and IL-2 release in response to mitogens.
authors.affiliation: Department of Experimental Medicine, Section of Biochemistry and Center of Excellence for Biomedical Research, University of Genova, Genova, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: Magnone
authors.forename: Inga
authors.initials: I
authors.lastname: Bauer
authors.forename: Alessandro
authors.initials: A
authors.lastname: Poggi
authors.forename: Elena
authors.initials: E
authors.lastname: Mannino
authors.forename: Laura
authors.initials: L
authors.lastname: Sturla
authors.forename: Marisa
authors.initials: M
authors.lastname: Brini
authors.forename: Elena
authors.initials: E
authors.lastname: Zocchi
authors.forename: Antonio
authors.initials: A
authors.lastname: De Flora
authors.forename: Alessio
authors.initials: A
authors.lastname: Nencioni
authors.forename: Santina
authors.initials: S
authors.lastname: Bruzzone
mesh_terms: D000178:Acrylamides / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D036563:Cyclic ADP-Ribose / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism; D015640:Ion Channel Gating / Q000187:drug effects* / Q000502:physiology; D019169:Jurkat Cells; D008934:Mitogens / Q000494:pharmacology*; D009243:NAD / Q000235:genetics / Q000378:metabolism*; D054409:Nicotinamide Phosphoribosyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D050053:TRPM Cation Channels / Q000235:genetics / Q000378:metabolism*; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D000178:Acrylamides; D016207:Cytokines; D004791:Enzyme Inhibitors; C508594:IL2 protein, human; D007376:Interleukin-2; D008934:Mitogens; C480543:N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide; D010880:Piperidines; D050053:TRPM Cation Channels; C121934:TRPM2 protein, human; D009243:NAD; D036563:Cyclic ADP-Ribose; D019284:Thapsigargin; D054409:Nicotinamide Phosphoribosyltransferase; C085455:nicotinamide phosphoribosyltransferase, human; D002118:Calcium