title: Interleukin-10 expression is induced by increase of intracellular calcium levels in the monocytic cell line U937.
abstract: The regulation of interleukin-10 (IL-10) expression after treatment with a high, exponential, electric pulse was investigated in the monocytic cell line U937. Recently, we showed IL-10 protein production in the monocytic cell lines U937 and THP-1 after exposure to a single, high exponential electric pulse [Lehmann MH, Höffken K, Berg H (1996) Bioelectrochem. Bioenerg. 41: 227-229]. In the present study, the specificity of this process was proven by semiquantitative reverse-transcriptase polymerase chain reaction. It was found that the presence of calcium in the culture medium during the pulse is essential for IL-10 protein production. Only a small amount of IL-10 protein was produced in calcium free medium. The calcium specific chelator EGTA prevented IL-10 protein production induced by the electric pulse in a dose-dependent manner. Additionally, IL-10 mRNA transcription could be induced in U937 cells without pulse application by means of the calcium ionophore ionomycin. No IL-10 protein could be detected by ELISA. However, down-regulation of TNF-alpha mRNA levels after ionomycin stimulation provided an indirect proof that IL-10 protein production occurred.
authors.affiliation: Friedrich-Schiller-Universität Jena, Clinic of Internal Medicine III and Institute of Clinical Pharmacology, Erlanger Allee 101, D-07740 Jena, Germany.
authors.forename: M H
authors.initials: MH
authors.lastname: Lehmann
authors.forename: H
authors.initials: H
authors.lastname: Berg
mesh_terms: D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D018274:Electroporation; D015870:Gene Expression; D006801:Humans; D016753:Interleukin-10 / Q000235:genetics*; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D002614:Chelating Agents; D007476:Ionophores; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D004533:Egtazic Acid; D015759:Ionomycin; D012194:RNA-Directed DNA Polymerase; D002118:Calcium