title: Synthesis and biological evaluation of novel membrane-permeant cyclic ADP-ribose mimics: N1-[(5''-O-phosphorylethoxy)methyl]-5'-O-phosphorylinosine 5',5''-cyclicpyrophosphate (cIDPRE) and 8-substituted derivatives.
abstract: N1-[(5' '-O-Phosphorylethoxy)methyl]-5'-O-phosphorylinosine 5',5''-cyclicpyrophosphate (cIDPRE 2a) and the 8-substituted derivatives 8-bromo-, 8-azido-, 8-amino-, and 8-Cl-cIDPRE (2b-e) were synthesized from N1-[(5''-acetoxyethoxy)methyl]-2',3'-O-isopropylideneinosine (5) in good yields. The pharmacological activities of cIDPRE and the 8-substituted derivatives (2a-e) were analyzed in intact and permeabilized human Jurkat T-lymphocytes. The results indicate that cIDPRE permeates the plasma membrane, releases Ca2+ from an intracellular, cADPR-sensitive Ca2+ store, and subsequently initiates Ca2+ release-activated Ca2+ entry. The Ca(2+)-releasing activity of cIDPRE was confirmed directly in permeabilized cells. Using time-resolved confocal Ca2+ imaging at the single cell level, the development of global Ca2+ signals starting from local small Ca2+ signals evoked by cIDPRE was observed. 8-N3-cIDPRE 2c and 8-NH2-cIDPRE 2d were similarly effective in their agonistic activity as compared to cIDPRE 2a, showing almost indistinguishable concentration-response curves for 2a, 2c, and 2d and very similar kinetics of Ca2+ signaling. In contrast, the halogenated derivatives 8-Br- and 8-Cl-cIDPRE (2b and 2e) did not significantly elevate [Ca2+]i. Therefore, cIDPRE 2a, 8-N3-cIDPRE 2c, and 8-NH2-cIDPRE 2d are novel membrane permeant cADPR mimic and may provide important novel tools to study cADPR-mediated Ca2+ signaling in intact cells.
authors.affiliation: National Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100083, China.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Gu
authors.forename: Zhenjun
authors.initials: Z
authors.lastname: Yang
authors.forename: Liangren
authors.initials: L
authors.lastname: Zhang
authors.forename: Svenja
authors.initials: S
authors.lastname: Kunerth
authors.forename: Ralf
authors.initials: R
authors.lastname: Fliegert
authors.forename: Karin
authors.initials: K
authors.lastname: Weber
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Guse
authors.forename: Lihe
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000737:chemistry*; D020013:Calcium Signaling / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D007291:Inosine Monophosphate / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D019169:Jurkat Cells; D018716:Molecular Mimicry; D010539:Permeability; D013329:Structure-Activity Relationship
chemical_list: C494342:N(1)-((5''-O-phosphorylethoxy)methyl)-5'-O-phosphorylinosine 5',5''-cyclic pyrophosphate; D007291:Inosine Monophosphate; D000246:Adenosine Diphosphate Ribose