Sodium arsenite-induced TFE3 and TFEB activation is inhibited by okadaic acid.
A, immunoblot analysis of protein lysates from ARPE19 cells treated with 250 μm NaAsO2 in the presence of the indicated concentration of Calcineurin inhibitor FK506 for 1 h. B, immunoblot analysis of protein lysates from a MLIV patient and unrelated nondiseased fibroblasts treated with 250 μm NaAsO2 for 1 h. C and D, immunoblot analysis of protein lysates from ARPE19 cells and HeLa (CF7) cells treated with 250 μm NaAsO2 in the presence of the indicated concentration of okadaic acid for 1 h. E, ARPE19 cells treated with either vehicle or 250 μm NaAsO2 for 1 h in the presence of 400 nm okadaic acid were fixed, permeabilized, and immunostained with antibodies against TFE3. Scale bar, 10 μm. F, quantification of cells with TFE3 in nucleus in either vehicle or NaAsO2 and okadaic acid-treated ARPE19 cells as shown in E. Vehicle, n = 517; OA, n = 556 NaAsO2, n = 524; and NaAsO2 + OA, n = 548 from three independent experiments. Error bars denote S.D. p value was calculated using one-way ANOVA, (**) p < 0.01, (****) p < 0.0001. Immunoblots are representative of three independent experiments.