Premium
Signal transduction of lyso‐type phosphatidylethanolamine lipids on intracellular calcium concentration in dopaminergic cells
Author(s) -
Park Soojin,
Im Dongsoon
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.lb515
Subject(s) - phosphatidylethanolamine , intracellular , chemistry , calcium , lysophosphatidic acid , biochemistry , phospholipase c , receptor , microbiology and biotechnology , biology , phospholipid , phosphatidylcholine , organic chemistry , membrane
Background Metabolic products of phosphatidylethanolamines, lyso‐type phosphatidylethanolamine lipids, shortly LPEL, are produced by phospholipase A 2 . LPEL increased intracellular Ca 2+ concentration in mammalian cells. G‐protein‐coupled receptor (GPCR) were supposed to be involved in the response. GPCRs for lysophosphatidic acid (LPA) might be responsible for the action in certain cell types but not in others. In the present study, action mode of LPEL on [Ca 2+ ] i in human dopaminergic cells was studied. METHODS Human dopaminergic cells were cultured at 37°C in a 5% CO 2 humidified incubator, and maintained in high glucose RPMI1640, containing 5% (v/v) heat‐inactivated horse serum, 100 units/mL penicillin, 50 μg/mL streptomycin, 2 mM glutamine, and 1 mM sodium pyruvate. Intracellular Ca 2+ concentration was measured in the cells that were trypsin‐digested, allowed to sediment, resuspended in Hepes‐buffered medium, and then incubated for 40 min with 5 μM of fura 2‐AM. [Ca 2+ ] i levels were estimated by measuring changes in fura 2 fluorescence using a fluorescence spectrophotometer. RESULTS LPEL induced increase of [Ca 2+ ] i in the dopaminergic cells. Also, LPA induced similar increase of [Ca 2+ ] i in the cells. LPEL‐ and LPA‐induced responses showed homologous and heterologous desensitization. Structurally different antagonists of LPA 1/3 , Ki16425 and VPC32183 inhibited LPEL‐induced increase of [Ca 2+ ] i . And a specific inhibitor of LPA 1 , AM‐095, also inhibited the LPEL‐induced Ca 2+ response completely in dopaminergic cells. Expression of LPA 1 and LPA 6 was found in the cells, but not other LPA receptors. Pertussis toxin, s specific inhibitor of G i/o proteins completely inhibited LPEL‐induced [Ca 2+ ] i increase. And edelfosine, an inhibitor of phospholipase C, and 2‐APB, an inhibitor of IP 3 receptor, also completely inhibited LPEL‐induced Ca 2+ responses. HA130, an inhibitor of autotaxin/lysophospholipase D, didn't inhibited LPEL‐induced response. DISCUSSION In the present study, LPEL‐induced [Ca 2+ ] i increase was found to be mediated via LPA 1 in dopaminergic cells. Heterologous desensitization, complete inhibition by AM‐095, LPA 1 antagonist, and G i/o ‐coupling character of LPA 1 and the PTX‐sensitivity of LPEL‐induced [Ca 2+ ] i increase strongly supported the hypothesis in dopaminergic cells. Also results indicate that LPEL increases [Ca 2+ ] i sequentially via LPA 1 receptors, G i/o proteins, phospholipase C, IP 3 , Ca 2+ rise, and Ca 2+ influx in the dopaminergic cells.