Characterization of lysophosphatidylcholine-induced changes of intracellular calcium in Drosophila S2 cells

AimsLysophosphatidylcholine (LPC), a bioactive lipid, regulates a wide array of biological processes. LPC could be deacylated to form glycerophosphocholine by neuropathy target esterase (NTE)/Swiss cheese protein (SWS). Although NTE/SWS is important in maintaining Ca2 + homeostasis, the role of LPC in regulating the intracellular calcium concentration ([Ca2 +]i) in Drosophila remains poorly understood. We aimed to study the mechanism of LPC-induced [Ca2 +]i changes in Drosophila S2 cells.Main methodsThe [Ca2 +]i of Drosophila S2 cells was measured by fluorescence spectrophotometry after loading the cells with the calcium-sensitive fluorescent probe Fura-2/AM.Key findingsOur results demonstrated that LPC could cause a rapid, dose-dependent increase in the [Ca2 +]i in the presence of external calcium ([Ca2 +]e). The LPC-induced [Ca2 +]i increase was reduced by 60.7% in the absence of [Ca2 +]e. Furthermore, the Ca2 + influx was inhibited by 37.3% after the cells were preincubated with an L-type Ca2 + channel blocker. In the Ca2 +-free medium, the LPC-induced [Ca2 +]i increase was completely blocked using an inositol triphosphate receptor (IP3R) inhibitor. However, a ryanodine receptor (RyR) inhibitor had no effect on the LPC-induced [Ca2 +]i increase.SignificanceThe LPC-induced [Ca2 +]i increase in S2 cells was dependent on both the release of Ca2 + stored in the endoplasmic reticulum and [Ca2 +]e influx. Both L-type Ca2 + channels and IP3R might be involved in this process. The LPC-induced [Ca2 +]i increase in S2 cells characterized in this study may shed light on the study of NTE/SWS protein function in general because the enzyme is responsible for the deacylation of LPC.