Retinal neurodegenerative changes in the adult insulin receptor substrate-2 deficient mouse

Research output: Contribution to journalArticlepeer-review

Authors

  • Mara Albert-Fort
  • Sheila Pons-Vazquez
  • Silvia Sanz-Gonzalez
  • Manuel Diaz-Llopis
  • María Dolores Pinazo-Durán

Colleges, School and Institutes

Abstract

Insulin receptor substrate-2 (Irs2) mediates peripheral insulin action and is essential for retinal health. Previous investigations have reported severe photoreceptor degeneration and abnormal visual function in Irs2-deficient mice. However, molecular changes in the Irs2−/− mouse retina have not been described. In this study, we examined retinal degenerative changes in neuronal and glial cells of adult (9- and 12-week old) Irs2−/− mice by immunohistochemistry. 9-week old Irs2−/− mice showed significant thinning of outer retinal layers, concomitant to Müller and microglial cell activation. Photoreceptor cells displayed different signs of degeneration, such as outer/inner segment atrophy, redistribution of rod- and cone-opsins and spatial disorganization of cone cells. This was accompanied by synaptic changes at the outer plexiform layer, including the retraction of rod-spherules, reduction of photoreceptor synaptic ribbons and synaptic remodeling in second order neurons (i.e. loss and sprouting of dendritic processes in rod bipolar and horizontal cells). By 12 weeks of age, the thickness of inner retinal layers was severely affected. Although inner plexiform layer stratification remained unchanged at this stage, rod bipolar cell axon terminals were significantly depleted. Significant loss of Brn3a+ retinal ganglion cells occurred in 12-week old Irs2−/− mice, in contrast to younger ages. Adult Irs2−/− mice showed clear hallmarks of neurodegeneration and disruption of the inner retina with increasing age. Pharmacological stimulation of Irs2 signaling pathway may provide additional neuroprotection in certain degenerative retinopathies.

Bibliographic note

Copyright © 2014 Elsevier Ltd. All rights reserved.

Details

Original languageEnglish
Pages (from-to)1-10
Number of pages10
JournalExperimental Eye Research
Volume124
Early online date2 May 2014
Publication statusPublished - 1 Jul 2014

Keywords

  • Animals, Disease Models, Animal, Electroretinography, Immunohistochemistry, Insulin Receptor Substrate Proteins, Mice, Inbred C57BL, Microscopy, Confocal, Photoreceptor Cells, Vertebrate, Retinal Bipolar Cells, Retinal Degeneration, Retinal Ganglion Cells, Vision, Ocular, Journal Article, Research Support, Non-U.S. Gov't, retina, Irs2, neuroprotection, synaptic plasticity, reactive gliosis, microglia