Albumin inhibits cytotoxic activity of lysophosphatidylcholine by direct binding.
Fetal bovine serum (FBS) was found to protect Jurkat T cells from LPC-induced cytotoxicity. Twenty micromolar LPC-induced cytotoxicity of 80-90% of the cells in media without FBS for 3 h, whereas 50-70% in media with 0.5% FBS. However, LPC-induced cytotoxicity was not observed in the presence of 5% FBS in media. The cytotoxicity was specific for LPC among lysophospholipids tested and significantly observed with palmitoyl (C16:0) LPC, stearoyl (C18:0) LPC, and oleoyl (C18:1) LPC among 11 synthetic LPCs. Furthermore, the cytoprotective effect of FBS was observed only when it was added before the treatment, but not after the treatment of LPC, and premixing of FBS and LPC before addition to the cells ameliorated LPC-induced cytotoxicity. Finally, albumin, a major constituent of FBS, prevented completely LPC-induced cytotoxicity even at as low as 3 microM concentration. We also found that five molecules of LPC could sequentially bind to one BSA using isothermal titration calorimetry. The above results suggest that the cytotoxic activity of LPC could be attenuated by albumin in blood. Finally, it should be cautioned that, when experiments are conducted with LPC dissolved in assay buffers containing albumin, the albumin in the buffer could influence the results.
Kim
Yu-Lee
YL
Laboratory of Pharmacology, College of Pharmacy and Research Institute for Drug Development, Pusan National University, San 30, Jang-Jun-dong, Geum-Jung-gu, Busan 609-735, Republic of Korea.
Im
Young-Jin
YJ
Ha
Nam-Chul
NC
Im
Dong-Soon
DS
D000818:Animals; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D005227:Fatty Acids; D006801:Humans; D019169:Jurkat Cells; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D012710:Serum Albumin, Bovine / Q000494:pharmacology*
D005227:Fatty Acids; D008244:Lysophosphatidylcholines; D012710:Serum Albumin, Bovine