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Geographic atrophy (GA), an untreatable advanced form of age-related macular degeneration, results from retinal pigmented epithelium (RPE) cell degeneration. Here we show that the microRNA (miRNA)-processing enzyme DICER1 is reduced in the RPE of humans with GA, and that conditional ablation of Dicer1, but not seven other miRNA-processing enzymes, induces RPE degeneration in mice. DICER1 knockdown induces accumulation of Alu RNA in human RPE cells and Alu-like B1 and B2 RNAs in mouse RPE. Alu RNA is increased in the RPE of humans with GA, and this pathogenic RNA induces human RPE cytotoxicity and RPE degeneration in mice. Antisense oligonucleotides targeting Alu/B1/B2 RNAs prevent DICER1 depletion-induced RPE degeneration despite global miRNA downregulation. DICER1 degrades Alu RNA, and this digested Alu RNA cannot induce RPE degeneration in mice. These findings reveal a miRNA-independent cell survival function for DICER1 involving retrotransposon transcript degradation, show that Alu RNA can directly cause human pathology, and identify new targets for a major cause of blindness.

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Change history

  • 16 March 2011

    In the paragraph beginning, ‘Subretinal injection delivered Alu RNA to RPE cells...’, two figure citations were corrected.


Data deposits

The Alu sequences have been deposited in GenBank under the accession numbers HN176584 and HN176585.


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We thank M. Chrenek, J. Garcia-Perez, T. Heidmann, C. Kanellopoulou, D. M. Livingston, J. V. Moran, R. F. Mullins, J. M. Nickerson, E. A. Pearce, A. Tarakhovsky, B. Vogelstein, V. E. Velculescu and D. J. Zack for providing mice, reagents or tissues; R. King, L. Xu, M. McConnell, C. Payne, G. R. Pattison, G. J. Jaffe, S. Medearis and C. Spee for technical assistance; and A. Sinai, R. Mohan, T. S. Khurana, R. A. Brekken, P. L. Deininger, S. Bondada, P. A. Pearson, A. M. Rao, G. S. Rao and K. Ambati for discussions. J.A. was supported by National Eye Institute (NEI)/National Institutes of Health (NIH) grants R01EY015422, R01EY018350, R01EY018836, R01EY020672, R21EY019778, RC1EY020442, the Doris Duke Distinguished Clinical Scientist Award, the Burroughs Wellcome Fund Clinical Scientist Award in Translational Research, and the Dr E. Vernon Smith and Eloise C. Smith Macular Degeneration Endowed Chair. Research to Prevent Blindness Senior Scientist Investigator Awards or departmental unrestricted grants supported J.A., H.E.G. and W.W.H.; J.Z.B. was supported by University of Kentucky Physician Scientist Award, International Retinal Research Foundation, and American Health Assistance Foundation; B.K.A. by VA Merit Award and Department of Defense; D.-k.L. by Global Research Laboratory program by MEST, Korea; D.R.H. by Arnold and Mabel Beckman Foundation; W.W.H. by Macular Vision Research Foundation and Foundation Fighting Blindness; J.M.P. by ARC Centres of Excellence Grant CE0561903; M.C.M. by Sydney Foundation for Medical Research. B.K.A was supported by NIH R01EY017182 and R01EY017950; R.E.B. by NIH R01HD027215; G.C. by NIH R21AI076757; H.E.G. by NIH P30EY06360; W.W.H. by NIH U10EY013729, R01EY011123, and P30EY008571; J.F.K. and J.A.G. by NIH R01GM068414; J.L.D. by NIH R01EY015240; D.R.H. by NIH P30EY003040 and R01EY001545; M.E.K. and S.B. by NIH T32HL091812. P.P. is a Senior Scholar from the Fonds de la Recherche en Santé du Québec (FRSQ). M.M.W.C. is a QEII Fellow of the Australian Research Council and is supported by National Health and Medical Research Council, Australia Project Grant 637228. E.F. and D.R.L. are investigators of the Howard Hughes Medical Institute.

Author information

Author notes

    • Hiroki Kaneko
    • , Sami Dridi
    •  & Valeria Tarallo

    These authors contributed equally to this work.


  1. Department of Ophthalmology & Visual Sciences, University of Kentucky, Lexington, Kentucky 40506, USA

    • Hiroki Kaneko
    • , Sami Dridi
    • , Valeria Tarallo
    • , Bradley D. Gelfand
    • , Benjamin J. Fowler
    • , Won Gil Cho
    • , Mark E. Kleinman
    • , Nikki L. Justice
    • , Romulo J. C. Albuquerque
    • , Alexander D. Blandford
    • , Sasha Bogdanovich
    • , Yoshio Hirano
    • , Judit Z. Baffi
    •  & Jayakrishna Ambati
  2. Department of Anatomy, Yonsei University Wonju College of Medicine, Wonju City 220-701, Korea

    • Won Gil Cho
  3. Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado 80309, USA

    • Steven L. Ponicsan
    • , Jennifer F. Kugel
    •  & James A. Goodrich
  4. Department of Ophthalmology, University of Florida, Gainesville, Florida 32610, USA

    • William W. Hauswirth
    •  & Vince A. Chiodo
  5. Department of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA

    • Katalin Karikó
  6. Global Research Laboratory for RNAi Medicine & BK21 School of Chemical Materials Science and Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea

    • Jae Wook Yoo
    •  & Dong-ki Lee
  7. F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA

    • Majda Hadziahmetovic
    • , Ying Song
    • , Ann H. Milam
    •  & Joshua L. Dunaief
  8. Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee 37208, USA

    • Smita Misra
    •  & Gautam Chaudhuri
  9. The Jackson Laboratory, Bar Harbor, Maine 04609, USA

    • Frank W. Buaas
    •  & Robert E. Braun
  10. The Arnold and Mabel Beckman Macular Research Center at the Doheny Eye Institute, University of Southern California, Los Angeles, California 90033, USA

    • David R. Hinton
  11. Departments of Ophthalmology & Pathology, Emory University Atlanta, Georgia 30322, USA

    • Qing Zhang
    •  & Hans E. Grossniklaus
  12. ARC Centre of Excellence in Vision Science, ANU Medical School and Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 0200, Australia

    • Jan M. Provis
  13. School of Optometry and Vision Science, The University of New South Wales, Kensington, New South Wales 2033, Australia

    • Michele C. Madigan
  14. Save Sight Institute, The University of Sydney, Sydney, New South Wales2001, Australia

    • Michele C. Madigan
  15. Department of Internal Medicine, University of Kentucky, Lexington, Kentucky 40506, USA

    • Jassir Witta
  16. Howard Hughes Medical Institute, Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, New York 10065, USA

    • Elaine Fuchs
  17. Howard Hughes Medical Institute, The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, New York 10016, USA

    • Dan R. Littman
    •  & Mark M. W. Chong
  18. Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA

    • Balamurali K. Ambati
  19. Department of Ophthalmology, Veterans Affairs Salt Lake City Healthcare System, Salt Lake City, Utah 84148, USA

    • Balamurali K. Ambati
  20. Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Johns Hopkins University, Baltimore, Maryland, 21231, USA

    • Charles M. Rudin
  21. The Walter and Eliza Hall Institute, Autoimmunity and Transplantation Division, Parkville, Victoria 3052, Australia

    • Mark M. W. Chong
  22. CHUL Research Center/CHUQ and Faculty of Medicine, Université Laval, Quebec, Quebec G1K 7P4, Canada

    • Patrick Provost
  23. Department of Physiology, University of Kentucky, Lexington, Kentucky 40506, USA

    • Jayakrishna Ambati


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H.K., S.D., V.T., W.G.C., B.J.F., M.E.K., S.L.P., J.F.K., J.A.G., K.K., N.L.J., B.D.G., Y.H., R.J.C.A., A.D.B., S.B, J.W., M.H, Y.S. and J.Z.B. performed experiments. W.W.H., V.A.C, D.-k.L., J.W.Y., C.M.R, D.R.H., H.E.G., Q.Z., J.M.P., M.C.M., A.H.M., M.M.W.C., D.R.L., E.F., P.P., F.W.B., R.E.B., S.M., G.C. and J.L.D. provided tissues or reagents. J.A. conceived and directed the project, and wrote the paper with assistance from P.P., C.M.R., K.K., J.F.K., J.A.G., E.F., M.M.W.C., B.J.F., B.D.G. and B.K.A. All authors had the opportunity to discuss the results and comment on the manuscript.

Competing interests

J.A. is named as an inventor on patent applications filed by his employer, the University of Kentucky, on technologies described in this paper. W.W.H. and the University of Florida have a financial interest in the use of AAV therapies, and own equity in a company (AGTC Inc.) that might, in the future, commercialize some aspects of this work.

Corresponding author

Correspondence to Jayakrishna Ambati.

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