Purchase this article with an account.
Catherine Cheng, Kehao Wang, Masato Hoshino, Kentaro Uesugi, Naoto Yagi, Barbara Pierscionek; EphA2 Affects Development of the Eye Lens Nucleus and the Gradient of Refractive Index. Invest. Ophthalmol. Vis. Sci. 2022;63(1):2. doi: https://doi.org/10.1167/iovs.63.1.2.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Our studies in mouse eye lenses demonstrate that ephrin-A5 and EphA2 are needed for normal epithelial cells and lens transparency. We sought to determine whether EphA2 and ephrin-A5 are important for lens morphometrics, nucleus formation, and refractive index.
We performed tissue morphometric measurements, electron microscopy, Western blots, and interferometric measurements using an X-ray synchrotron beam source to measure the gradient of refractive index (GRIN) to compare mouse lenses with genetic disruption of EphA2 or ephrin-A5.
Morphometric analysis revealed that although there is no change in the overall lens volume, there is a change in lens shape in both EphA2−/− lenses and ephrin-A5−/− lenses. Surprisingly, EphA2−/− lenses had small and soft lens nuclei different from hard lens nuclei of control lenses. SEM images revealed changes in cell morphology of EphA2−/− fiber cells close to the center of the lens. Inner EphA2−/− lens fibers had more pronounced tongue-and-groove interdigitations and formed globular membrane morphology only in the deepest layers of the lens nucleus. We did not observe nuclear defects in ephrin-A5−/− lenses. There was an overall decrease in magnitude of refractive index across EphA2−/− lenses, which is most pronounced in the nucleus.
This work reveals that Eph-ephrin signaling plays a role in fiber cell maturation, nuclear compaction, and lens shape. Loss of EphA2 disrupts the nuclear compaction resulting in a small lens nucleus. Our data suggest that Eph-ephrin signaling may be required for fiber cell membrane reorganization and compaction and for establishing a normal GRIN.
This PDF is available to Subscribers Only