title: Characterization of protoberberine analogs employed as novel human P2X7 receptor antagonists.
abstract: The P2X(7) receptor (P2X(7)R), a member of the ATP-gated ion channel family, is regarded as a promising target for therapy of immune-related diseases including rheumatoid arthritis and chronic pain. A group of novel protoberberine analogs (compounds 3-5), discovered by screening of chemical libraries, was here investigated with respect to their function as P2X(7)R antagonists. Compounds 3-5 non-competitively inhibited BzATP-induced ethidium ion influx into hP2X(7)-expressing HEK293 cells, with IC(50) values of 100-300nM. This antagonistic action on the channel further confirmed that both BzATP-induced inward currents and Ca(2+) influx were strongly inhibited by compounds 3-5 in patch-clamp and Ca(2+) influx assays. The antagonists also effectively suppressed downstream signaling of P2X(7) receptors including IL-1β release and phosphorylation of ERK1/2 and p38 proteins in hP2X(7)-expressing HEK293 cells or in differentiated human monocytes (THP-1 cells). Moreover, IL-2 secretion from CD3/CD28-stimulated Jurkat T cell was also dramatically inhibited by the antagonist. These results imply that novel protoberberine analogs may modulate P2X(7) receptor-mediated immune responses by allosteric inhibition of the receptor.
authors.affiliation: School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
authors.forename: Ga Eun
authors.initials: GE
authors.lastname: Lee
authors.forename: Won-Gil
authors.initials: WG
authors.lastname: Lee
authors.forename: Song-Yi
authors.initials: SY
authors.lastname: Lee
authors.forename: Cho-Rong
authors.initials: CR
authors.lastname: Lee
authors.forename: Chul-Seung
authors.initials: CS
authors.lastname: Park
authors.forename: Sunghoe
authors.initials: S
authors.lastname: Chang
authors.forename: Sung-Gyoo
authors.initials: SG
authors.lastname: Park
authors.forename: Mi-Ryoung
authors.initials: MR
authors.lastname: Song
authors.forename: Yong-Chul
authors.initials: YC
authors.lastname: Kim
mesh_terms: D001600:Berberine Alkaloids / Q000737:chemistry* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D057809:HEK293 Cells; D006801:Humans; D019169:Jurkat Cells; D058919:Purinergic P2 Receptor Antagonists / Q000737:chemistry* / Q000494:pharmacology*; D058486:Receptors, Purinergic P2X7 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D001600:Berberine Alkaloids; D058919:Purinergic P2 Receptor Antagonists; D058486:Receptors, Purinergic P2X7; C009090:protoberberine