Article Figures & Data
Figures
- Fig. 1.
Interaction between OATP and OCT(N) transporters and antimalarial compounds. E1S (1 µM, 5 minutes, OATP1A2, OATP2B1), MPP+ (0.5 µM, 1.5 minutes, OCT1–3) and TEA (0.3 µM, 5 minutes, OCTN1) uptake was studied in transporter-overexpressing MDCKII cells in the presence and absence of the respective compound (each 100 µM) as well as in vector-transfected control cells (MDCKII). Data are represented in relation to transporter-overexpressing cells (100%, dotted line), mean+ S.D., n = 2–4, one-way analysis of variance and Dunnett’s multiple comparison test versus control-treated MDCKII-OATP1A2 cells; *P < 0.05, **P < 0.01, ***P < 0.001. Inserts: Immunofluorescence staining of respective transporter (bars: 20 µm).
- Fig. 2.
Determination of half-maximal inhibitory concentrations (IC50 values) of quinine, chloroquine, and mefloquine for OATP1A2-mediated E1S transport (1 µM, 5 minutes). Data represent the background corrected mean values (mean ± S.D., n = 3–4).
- Fig. 3.
Quinine uptake into transporter-overexpressing MDCKII cells. (A) Time-dependent quinine uptake (1 µM) at pH 7.3 into OATP1A2- and OATP2B1-overexpressing MDCKII cells (mean ± S.D., n = 3–4). (B) OATP1A2-mediated quinine uptake (1 µM) at pH 7.3 and pH 6.0 (hatched columns) (mean ± S.D., n = 3, two-way analysis of variance and Tukey’s multiple comparison test, *P < 0.05, **P < 0.01, ***P < 0.001). (C) Sensitivity of OATP1A2-mediated quinine uptake (1 µM, 30 minutes) to the OATP1A2 inhibitor naringin (100 µM) at pH 7.3 and pH 6.0 (mean ± S.D., n = 3, one-way analysis of variance and Tukey’s multiple comparison test, *P < 0.05, **P < 0.01). (D) Concentration-dependent uptake of quinine (0.78–100 µM, 5 minutes) at pH 7.3 by OATP1A2. OATP1A2-specific transport was used to calculate kinetic parameters (mean ± S.D., n = 6).
- Fig. 4.
(A) Immunofluorescence staining of OATP1A2 and OATP2B1 in RBC. Whole-blood smears were probed against OATP1A2 and OATP2B1 (both green). Costaining was performed with the erythrocyte membrane marker CD235a (red). Control stainings with preimmune serum exhibited no specific signals (inserts). Scale bar: 5 µm. (B) Immunoblot of crude membrane fractions of RBC and transporter-overexpressing MDCKII cells (control) using OATP-specific antibodies. (C) In vitro uptake of quinine (100 nM) into RBCs measured at 37°C and 4°C in the presence and absence of the OATP1A2 inhibitor naringin (100 µM) (mean ± S.D., n = 4 RBC preparations, one-way analysis of variance and Tukey’s multiple comparison test, *P < 0.05, **P < 0.01).
Tables
- TABLE 1
Half-maximal inhibitory concentrations (IC50 values) and maximal inhibitory effects of selected antimalarial compounds for OATP1A2, OCT1, and OCT2
Data represent background corrected IC50 values (mean ± S.D.) from three to four experiments.
Compound OATP1A2 OCT1 OCT2 IC50 Maximum Inhibitory Effect IC50 Maximum Inhibitory Effect IC50 Maximum Inhibitory Effect µM % µM % µM % Quinine 0.7 ± 1.2 94 3.5 ± 7.6 85 5.9 ± 3.2 92 Chloroquine 1.0 ± 1.5 60 12.8 ± 9 1 80 8.9 ± 5.4 87 Mefloquine 6.0 ± 3.4 93 6.6 ± 6.5 70 14.6 ± 5.8 87 Pyrimethamine — — 8.5 ±.1.9 88 3.4 ± 1.4 100 Artemisinin — — 4.2 ± 5.5 88 — —
Data Supplement
Files in this Data Supplement:
- Supplemental Data -
Supplemental Figure 1 - Immunofluorescence staining of transporter-overexpressing MDCKII cells analyzed by a confocal microscope (LSM780, Zeiss)
Supplemental Figure 2 - Quinine uptake by OCT1 and 2 and naringin effect on MPP+ uptake
Supplemental Figure 3 - A. Immunofluorescence staining of OCTN1 in red blood cells (RBC, green)
- Supplemental Data -
In this issue
OATP1A2 and Antimalarial Compounds
