SLC2A9 Is a High-Capacity Urate Transporter in Humans
Figure 5
Expression of SLC2A9 and Urate Uptake into Mouse Insulinoma MIN6 Cells
(A) Western blotting of mouse SLC2A9 in MIN6 cells. Cell lysates were analyzed by Western blot using antibodies to murine SLC2A9a and SLC2A9b of MIN6 cell lysates.
(B) 14C-urate uptake into MIN6 cells is competitively inhibited by cold urate. Radiolabelled urate uptake was measured in mouse insulinoma cells, which endogenously express mSLC2A9a or mSLC2A9b. Uptake of 14C-urate, 120 μM, was measured for 6 min at 37 °C in the presence or absence of an additional 1mM cold urate. ** p < 0.02.
(C) SLC2A9a and SLC2A9b expression is reduced by treatment of MIN6 cells with siRNA specific for mSLC2A9. Cells were treated with either scrambled RNA (scRNA) or mSLC2A9-specific siRNA and cell lysates run on a Western blot and probed with an antibody specific for either mSLC2A9a (mGLUT9a) or mSLC2A9b (mGLUT9b).
(D) Reduction of urate uptake into MIN6 cells by transfection with siRNA targeted to SLC2A9. MIN6 cells were transfected with either SLC2A9-specific siRNA9 or scrambled RNA (scRNA). 14C-urate, 120 μM, uptake into transfected or untransfected cells was measured for 6 min at 37 °C. *p < 0.05.