Inhibitory effects of porphyrins and rhodocytin on podoplanin binding to CLEC-2–expressing T-REx-293 cells. (A) Chemical formula of H2-PP. Results of flow cytometric assays for detecting the inhibitory effects of H2-PP (i) and rhodocytin (ii) on the binding of podoplanin to CLEC-2–expressing T-REx-293 cells. Fill, DMSO + hFc2; red line, DMSO + hpod-hFc2; blue line, H2-PP (i) or rhodocytin (ii) + hpod-hFc2. (B) The chemical formulae of Co-protoporphyrin IX (Co-PP) (i), Cu-protoporphyrin IX (Cu-PP) (ii), and Pd-protoporphyrin IX (Pd-PP) (iii). Results of flow cytometric assays for detecting the inhibitory effects of Co-PP (i), Cu-PP (ii), and Pd-PP (iii) on the binding of podoplanin to CLEC-2–expressing T-REx-293 cells. Fill, DMSO + hFc2; red, DMSO + hpod-hFc2; blue, 20 μg/mL [28.1-33.0 μM] compound + hpod-hFc2. (C) The chemical formulae of hematoporphyrin (H2-HP) (i), Co- hematoporphyrin (Co-HP) (ii), Cu-hematoporphyrin (Cu-HP) (iii), and Pd-hematoporphyrin (Pd-HP). Results of the flow cytometric assays for the detection of the inhibitory effects of H2-HP (i), Co-HP (ii), Cu-HP (iii), and Pd-HP (iv) on the binding of podoplanin to CLEC-2–expressing T-REx-293 cells. Fill, DMSO + hFc2; red, DMSO + hpod-hFc2; blue, 20 μg/mL [28.4-33.4 μM] compound + hpod-hFc2. (D) Binding of hpod-hFc2 to CLEC-2–expressing T-REx-293 cells in the presence of indicated chemicals or rhodocytin. Results are expressed as the relative mean fluorescence intensity (MFI) ± standard deviation (SD) (n = 4, panels A-C) compared with MFI of control hFc2 binding.