title: Activation of CD38 by interleukin-8 signaling regulates intracellular Ca2+ level and motility of lymphokine-activated killer cells.
abstract: CD38 is an ADP-ribosyl cyclase, producing a potent Ca(2+) mobilizer cyclic ADP-ribose (cADPR). In this study, we have investigated a role of CD38 and its regulation through interleukin-8 (IL8) signaling in lymphokine-activated killer (LAK) cells. Incubation of LAK cells with IL8 resulted in an increase of cellular cADPR level and a rapid rise of intracellular Ca(2+) concentration ([Ca(2+)](i)), which was sustained for a long period of time (>10 min). Preincubation of an antagonistic cADPR analog, 8-Br-cADPR (8-bromo-cyclic adenosine diphosphate ribose), abolished the sustained Ca(2+) signal only but not the initial Ca(2+) rise. An inositol 1,4,5-trisphosphate (IP(3)) receptor antagonist blocked both Ca(2+) signals. Interestingly, the sustained Ca(2+) rise was not observed in the absence of extracellular Ca(2+). Functional CD38-null (CD38(-)) LAK cells showed the initial rapid increase of [Ca(2+)](i) but not the sustained Ca(2+) rise in response to IL8 treatment. An increase of cellular cADPR level by cGMP analog, 8-pCPT-cGMP (8-(4-chlorophenylthio)-guanosine-3',5'-cyclic monophosphate), but not cAMP analog or phorbol 12-myristate 13-acetate was observed. IL8 treatment resulted in the increase of cGMP level that was inhibited by the IP(3) receptor blocker but not a protein kinase C inhibitor. cGMP-mediated Ca(2+) rise was blocked by 8-Br-cADPR. In addition, IL8-mediated LAK cell migration was inhibited by 8-Br-cADPR and a protein kinase G inhibitor. Consistent with these observations, IL8-induced migration of CD38(-) LAK cells was not observed. However, direct application of cADPR or 8-pCPT-cGMP stimulated migration of CD38(-) cells. These results demonstrate that CD38 is stimulated by sequential activation of IL8 receptor, IP(3)-mediated Ca(2+) rise, and cGMP/protein kinase G and that CD38 plays an essential role in IL8-induced migration of LAK cells.
authors.affiliation: Department of Biochemistry, Chonbuk National University Medical School, Jeonju, 561-182, Republic of Korea.
authors.forename: So-Young
authors.initials: SY
authors.lastname: Rah
authors.forename: Kwang-Hyun
authors.initials: KH
authors.lastname: Park
authors.forename: Myung-Kwan
authors.initials: MK
authors.lastname: Han
authors.forename: Mie-Jae
authors.initials: MJ
authors.lastname: Im
authors.forename: Uh-Hyun
authors.initials: UH
authors.lastname: Kim
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000096:biosynthesis / Q000378:metabolism*; D051997:ADP-ribosyl Cyclase 1; D000244:Adenosine Diphosphate / Q000378:metabolism; D015703:Antigens, CD / Q000096:biosynthesis / Q000378:metabolism*; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement; D036563:Cyclic ADP-Ribose / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors; D016209:Interleukin-8 / Q000378:metabolism*; D015979:Killer Cells, Lymphokine-Activated / Q000378:metabolism*; D007700:Kinetics; D008562:Membrane Glycoproteins; D008954:Models, Biological; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000378:metabolism; D013997:Time Factors
chemical_list: D015703:Antigens, CD; D015220:Calcium Channels; C506926:ITPR1 protein, human; D053496:Inositol 1,4,5-Trisphosphate Receptors; D016209:Interleukin-8; D008562:Membrane Glycoproteins; D018160:Receptors, Cytoplasmic and Nuclear; D019837:Ryanodine Receptor Calcium Release Channel; D036563:Cyclic ADP-Ribose; D000244:Adenosine Diphosphate; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1; D006152:Cyclic GMP; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium