Fig. 5.

S1P₁ activation during LPS-induced systemic inflammation in live mice transplanted with plasmaS1Pless bone marrow. a Bone marrow cells from control or plasma(p)S1Pless mice were transplanted (BMT) into irradiated S1P₁ luciferase signaling (S1P₁LS) mice to produce control transplanted (Control-T) or pS1Pless transplanted (S1Pless-T) mice, respectively. LPS was injected intraperitoneally into the stably transplanted mice 20 weeks later. Mice were subjected to BLI prior to the LPS injection (baseline, B/L) and 2, 6, and 24 h after LPS injection. b Plasma S1P and dhS1P levels in S1P₁ luciferase signaling mice, transplanted with control (Control-T) or pS1Pless (S1Pless-T) bone marrow. Data represent the mean ± SEM. n = 6 for Control-T mice, n = 8 for S1Pless-T mice. c Representative bioluminescence images of the same S1P₁ luciferase signaling mice, transplanted with control (Cont-T) or pS1Pless (S1Pless-T) bone marrow, at the specified time points. Mice were imaged in the supine position. Red open rectangles representing ROI were positioned around cephalic, thoracic, and epigastric regions. d–f The bioluminescence activity was quantified by determining the total flux (photons/sec; p/sec) in the cephalic (d), thoracic (e), and epigastric (f) ROI. Data represent the mean ± SEM. n = 5 for control BM-transplanted S1P₁ luciferase signaling (Control-T) mice and n = 7 for pS1Pless BM-transplanted S1P₁ luciferase signaling (S1Pless-T) mice at the baseline, 2 h, and 6 h time points. n = 4 for control BM-transplanted S1P₁ luciferase signaling (Control-T) mice and n = 6 for pS1Pless BM-transplanted S1P₁ luciferase signaling (S1Pless-T) mice at 24 h. P values were determined two-tailed Student’ t-test; *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001