Early retinal neurodegeneration and impaired Ran-mediated nuclear import of TDP-43 in progranulin-deficient FTLD

Michael E. Ward, Alice Taubes, Robert Chen, Bruce L. Miller, Chantelle F. Sephton, Jeffrey M. Gelfand, Sakura Minami, John Boscardin, Lauren Herl Martens, William W. Seeley, Gang Yu, Joachim Herz, Anthony J. Filiano, Andrew E. Arrant, Erik D. Roberson, Timothy W. Kraft, Robert V. Farese, Ari Green, Li Gan

Research output: Contribution to journalArticle

44 Scopus citations

Abstract

Frontotemporal dementia (FTD) is the most common cause of dementia in people under 60 yr of age and is pathologically associated with mislocalization of TAR DNA/RNA binding protein 43 (TDP-43) in approximately half of cases (FLTD-TDP). Mutations in the gene encoding progranulin (GRN), which lead to reduced progranulin levels, are a significant cause of familial FTLD-TDP. Grn-KO mice were developed as an FTLD model, but lack cortical TDP-43 mislocalization and neurodegeneration. Here, we report retinal thinning as an early disease phenotype in humans with GRN mutations that precedes dementia onset and an age-dependent retinal neurodegenerative phenotype in Grn-KO mice. Retinal neuron loss in Grn-KO mice is preceded by nuclear depletion of TDP-43 and accompanied by reduced expression of the small GTPase Ran, which is a master regulator of nuclear import required for nuclear localization of TDP-43. In addition, TDP-43 regulates Ran expression, likely via binding to its 3'-UTR. Augmented expression of Ran in progranulindeficient neurons restores nuclear TDP-43 levels and improves their survival. Our findings establish retinal neurodegeneration as a new phenotype in progranulin-deficient FTLD, and suggest a pathological loop involving reciprocal loss of Ran and nuclear TDP-43 as an underlying mechanism.

Original languageEnglish (US)
Pages (from-to)1937-1945
Number of pages9
JournalJournal of Experimental Medicine
Volume211
Issue number10
DOIs
StatePublished - 2014

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Fingerprint Dive into the research topics of 'Early retinal neurodegeneration and impaired Ran-mediated nuclear import of TDP-43 in progranulin-deficient FTLD'. Together they form a unique fingerprint.

Cite this