Fig. 8.
Effect of S1P and LPA on the ability of Lin−/c-Kit+ bone marrow cells to invade stromal cell layers.
The 5 × 105 bone marrow–derived Lin−/c-Kit+ hematopoietic progenitor cells were seeded on TBR59 (A) and TBR311 (B) bone marrow stromal cell lines and cultured for 17 hours at 33°C with or without 5 μg/mL of the indicated lipids. Suspended hematopoietic cells were retrieved by incubation and rinsed with EDTA-PBS. Adhered and invaded cell numbers were obtained by subtracting the numbers of cells retrieved in the suspended fraction from the input cell numbers. LPA, lysophosphatidic acid; S1P, sphingosine-1-phosphate; SM, sphingomyelin; Sph, sphingosine; De-FBS, 5% delipid FBS by charcoal stripping. Data are the mean ± SD of 3 dishes: De-LPS + LPA versus De-LPS (P = .0074 by Bonferroni/Dunn test) and De-LPS + S1P versus De-LPS (P = .1802 by Bonferroni/Dunn test) in (A); De-LPS + LPA versus De-LPS (P < .0001 by Bonferroni/Dunn test) and De-LPS + S1P versus De-LPS (P = .024 by Bonferroni/Dunn test) in (B).