title: NPC-14686, a novel anti-inflammatory agent, increased intracellular Ca(2+) concentrations in MDCK renal tubular cells.
abstract: The effect of NPC-14686 (Fmoc-L-homophenylalanine), a novel anti-inflammatory agent on intracellular free Ca(2+) concentrations ([Ca(2+)](i)) in Madin Darby canine kidney (MDCK) renal tubular cells, was investigated, using fura-2 as a Ca(2+) dye. At concentrations between 10 and 200 microM NPC-14686 increased [Ca(2+)](i) concentration dependently. The [Ca(2+)](i) signal comprised an initial rise and a sustained phase. Ca(2+) removal inhibited the Ca(2+) signals by 90%. In Ca(2+)-free medium, pretreatment with 100 microM NPC-14686 nearly abolished the [Ca(2+)](i) increase induced by 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) and abolished the [Ca(2+)](i) increase induced by 2 microM carbonylcyanide m-chlorophenylhydrazone (CCCP) (a mitochondrial uncoupler). NPC-14686 (100 microM) induced a slight [Ca(2+)](i) increase after pretreatment with 2 microM CCCP and 1 microM thapsigargin. Addition of 3 mM Ca(2+) elicited a [Ca(2+)](i) increase in cells pretreated with 100 microM NPC-14686 in Ca(2+)-free medium. Inhibition of inositol-1,4,5-trisphosphate (IP(3)) production by suppressing phospholipase C with 2 microM U73122 did not alter NPC-14686-induced Ca(2+) release. Trypan blue exclusion revealed that incubation with 10 or 200 microM NPC-14686 for 1-30 min decreased cell viability by 10-20% concentration dependently. Collectively, the results demonstrate that, in MDCK tubular cells, NPC-14686 induced Ca(2+) release followed by Ca(2+) entry, with the latter playing a major role. NPC-14686 appears to release intracellular Ca(2+) in an IP(3)-uncoupled manner. NPC-14686 may be of mild cytotoxicity.
authors.affiliation: Department of Medical Education and Research, Kaohsiung Veterans General Hospital, 386 Ta Chung 1st Road, 813, Kaohsiung, Taiwan.
authors.forename: C R
authors.initials: CR
authors.lastname: Jan
authors.forename: J L
authors.initials: JL
authors.lastname: Wang
authors.forename: K J
authors.initials: KJ
authors.lastname: Chou
authors.forename: J S
authors.initials: JS
authors.lastname: Cheng
authors.forename: K C
authors.initials: KC
authors.lastname: Lee
authors.forename: L L
authors.initials: LL
authors.lastname: Tseng
authors.forename: S P
authors.initials: SP
authors.lastname: Wang
authors.forename: K Y
authors.initials: KY
authors.lastname: Tang
authors.forename: J K
authors.initials: JK
authors.lastname: Huang
mesh_terms: D000613:Aminobutyrates / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004285:Dogs; D015544:Inositol 1,4,5-Trisphosphate / Q000502:physiology; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000613:Aminobutyrates; D000893:Anti-Inflammatory Agents; C417979:NPC 14686; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium