Uptake of host S1P by the parasite. (A, panel I) Fluorescence microscopic images showing the uptake of NBD-Sph by Pf3D7 schizont-infected erythrocytes. The presence of NBD-S1P (green) in the parasite nuclei is depicted by its co-localization with Hoechst nuclear stain (blue). Scale bar: 5 μm. (A, panel II) Co-localization is further depicted by a representative scatterplot in which the green channel (NBD-S1P) is shown on the x axis and the blue channel (Hoechst) is shown on the y axis (Pearson’s correlation coefficient: 0.76). The inset shows a representative Giemsa-stained image of Pf3D7 schizont-infected erythrocyte. (B, panel I) Fluorescence microscopic images depicting the NBD-S1P levels in the host-free Pf3D7 parasites. NBD-S1P (green) was found to localize in the parasite nuclei (Hoechst; blue). Scale bar: 5 μm. (B, panel II) A representative scatterplot depicting co-localization, in which the green channel (NBD-S1P) is shown on the x axis, and the blue channel (Hoechst) is shown on the y axis (Pearson’s correlation coefficient: 0.96). The inset shows a representative Giemsa-stained image of the host-free Pf3D7 schizont. (C, panel I) Fluorescence micrographs indicating a reduction in the fluorescence intensities of NBD-S1P (green) in the parasite nucleus upon PF-543 (2 μM) treatment. (C, panel II) Estimates of mean fluorescence intensities of NBD-S1P in each condition are shown as a bar graph (n = 3; Student's t test; *, P ≤ 0.05). Sah RK, Anand S, Dar W, Jain R, Kumari G, Madan E, Saini M, Gupta A, Joshi N, Hada RS, Gupta N, Pati S, Singh S. Host-Erythrocytic Sphingosine-1-Phosphate Regulates Plasmodium Histone Deacetylase Activity and Exhibits Epigenetic Control over Cell Death and Differentiation. Microbiol Spectr. 2023 11(2):e0276622. PMID: 36744922