Akiba S, Hayama M, Sato T
Department of Pathological Biochemistry, Kyoto Pharmaceutical University, Japan.
FEBS Lett. 1998 Oct 23;437(3):225-8. doi: 10.1016/s0014-5793(98)01236-8.
Cytokine-induced prostaglandin generation in rat mesangial cells has been suggested to be dependent on the expression of secretory phospholipase A2 (sPLA2). In the present study, we investigated the possible involvement of Ca2+-independent phospholipase A2 (iPLA2) in the generation. The results showed that bromoenol lactone, a relatively selective iPLA2 inhibitor, significantly attenuated prostaglandin E2 generation induced by interleukin-1beta and dibutyryl cAMP in parallel with the inhibition of iPLA2 activity. However, the inhibitor did not affect sPLA2 release upon stimulation, activities of sPLA2 or cytosolic phospholipase A2, or Ca2+ ionophore-induced arachidonic acid liberation. These results suggest that prostaglandin E2 generation upon stimulation may be partially mediated by iPLA2 in addition to sPLA2.
细胞因子诱导的大鼠系膜细胞中前列腺素的生成被认为依赖于分泌型磷脂酶A2（sPLA2）的表达。在本研究中，我们调查了钙离子非依赖性磷脂酶A2（iPLA2）在该生成过程中可能的参与情况。结果显示，溴烯醇内酯，一种相对选择性的iPLA2抑制剂，显著减弱了白细胞介素-1β和二丁酰环磷腺苷诱导的前列腺素E2生成，同时抑制了iPLA2活性。然而，该抑制剂并不影响刺激后sPLA2的释放、sPLA2或胞质磷脂酶A2的活性，也不影响钙离子载体诱导的花生四烯酸释放。这些结果表明，刺激后前列腺素E2的生成除了由sPLA2介导外，可能还部分由iPLA2介导。
