June 2021
Volume 62, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2021
The D167A mutation in PDEA greatly depresses PDE expression but produces sensitive (though slower) rod responses and remarkably slow degeneration
Author Affiliations & Notes
  • Ala Morshedian
    Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, California, United States
  • Gabriela Sendek
    Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, California, United States
  • Sze Yin Ng
    Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, California, United States
  • Kimberly Boyd
    University of Iowa, Iowa City, Iowa, United States
  • Annia Abtout
    Institut de Biologie de l'École Normale Supérieure, Paris, France
  • Jürgen Reingruber
    Institut de Biologie de l'École Normale Supérieure, Paris, France
  • Nikolai Artemyev
    University of Iowa, Iowa City, Iowa, United States
  • Roxana A Radu
    Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, California, United States
  • Mingyao Liu
    Institute of Life Science, East China Normal University, Shanghai, China
  • Gordon L Fain
    Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, California, United States
  • Footnotes
    Commercial Relationships   Ala Morshedian, None; Gabriela Sendek, None; Sze Ng, None; Kimberly Boyd, None; Annia Abtout, None; Jürgen Reingruber, None; Nikolai Artemyev, None; Roxana Radu, None; Mingyao Liu, None; Gordon Fain, None
  • Footnotes
    Support  NIH
Investigative Ophthalmology & Visual Science June 2021, Vol.62, 3149. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Ala Morshedian, Gabriela Sendek, Sze Yin Ng, Kimberly Boyd, Annia Abtout, Jürgen Reingruber, Nikolai Artemyev, Roxana A Radu, Mingyao Liu, Gordon L Fain; The D167A mutation in PDEA greatly depresses PDE expression but produces sensitive (though slower) rod responses and remarkably slow degeneration. Invest. Ophthalmol. Vis. Sci. 2021;62(8):3149.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Mutations in the beta subunit of phosphodiesterase 6 expressed in rod photoreceptors have been shown to cause rapid retinal degeneration in mouse models such as rd1. In this study we demonstrate that the D167A mutation in PDEA leaves rods with less than 10% of normal PDE expression, but this is enough to protect the cells from precipitous degeneration.

Methods : The CRISPR-Cas system was used in mouse to convert the aspartic acid at position 167 of PDE6A to alanine. Protein content was measured by serial-dilution Western blots, and PDE activity was quantified with a biochemical assay. Retinal morphology was assessed and quantified with light microscopy. Single cell photocurrents were recorded from the outer-segment of mouse rods with suction-electrode recording, and a mathematical model was used to fit the collected data.

Results : The D167A mutation in the PDE6A results in a greater than 10-fold reduction in PDE6B, with PDE6A almost undetectable. A significant reduction in basal PDE6 catalytic activity as well as trypsin-activated PDE6 activity was observed in these retinas. Degeneration was slow, with 70% of rod nuclei still remaining at 6 months. No detectable changes were observed in the sensitivity of single cells, though activation and recovery of the photoresponse were both significantly slower. These changes could be mathematically modeled by a reduction in the dark rate of PDE (bd), a reduced rate of PDE activation, and a small elevation in dark Ca2+ concentration, all of which are compatible with a reduction in PDE activity.

Conclusions : The changes observed in the temporal properties of rod photoreceptors in the D167A animal can be explained by the reduction in PDE concentration and activity. The small PDE6B expression seems to be forming sufficient functional phosphodiesterase enzyme to provide protection against rapid degeneration.

This is a 2021 ARVO Annual Meeting abstract.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×