a, Human RPE cytotoxicity induced by DICER1 as rescued by Alu RNA as. Values normalized or compared to control (Ctrl) as. b, Ad-Cre but not Ad-Null induced Dicer1f/f mouse RPE cytotoxicity. B1/B2 RNA as, but not control (Ctrl) as, rescued viability. Values normalized to untreated cells (no Tx). * P < 0.05 by Student t test. n=4–6 (a,b). c, Subretinal AAV-BEST1-Cre induced RPE degeneration (blue arrowheads in fundus photograph, top row; ZO-1 stained (red) flatmounts, bottom row) in Dicer1f/f mice 20 days after injection was inhibited by subretinal cholesterol-conjugated B1/B2 as, but not cholesterol-conjugated Ctrl as, 10 days after AAV-BEST1-Cre injection. Values normalized to Ctrl as-treatment. n=8. Scale bar, 20 µm. d, DICER1 as induced global miRNA expression deficits in human RPE cells compared to Ctrl as. No significant difference in miRNA abundance between Alu as and Ctrl as-treated DICER1 depleted cells. n=3.