Abstract
Purpose :
Optic nerve degeneration and RGC loss are cardinal features of glaucoma, an irreversible ocular disease that accounts for the second leading cause (~10%) of blindness in the United States and world-wide. Our preliminary data has implicated novel functions of OPTN in maintaining retinal homeostasis. In the proposed study, by leveraging novel genetic, computational, and electrophysiological tools, we will explore the effects of loss-of-function mutations of OPTN in physiological and pathological conditions of the retina.
Methods :
We hypothesized that OPTN loss-of-function mutations may lead to optic neuropathy. We incorporated the hypothesize by designing two models to either knock out OPTN gene in most of the cells in retina or knocking out OPTN gene in specific cell of retina.
OPTN conventional knockout: Intravitreal injection of AAV2-Cre and AAV2-PLAP vectors
By administering AAV2-Cre to OPTNfl/fl mice, we induced the knockout of OPTN genes. Using intravitreal injections, we can effectively knock out the OPTN in most of the cells in retina. This allows us to examine the retinal changes that occur in the absence of the OPTN genes. The outcomes from experimental group are then compared with those from the control group, which received AAV2-PLAP injections.
OPTN conditional knockout: Breeding pairs to knock out OPTN in specific cells.
As we have the outcomes that the complete knock out of OPTN in the whole retina has pathological changes, then we are curious if the OPTN gene is cell autonomous or non-cell autonomous. In order to find out that question, we comply with a model which only knocks out OPTN in specific cells by breeding pair OPTNfl/fl mice with cell specific Cre mice (Vglut2-Cre)
Results :
Astrogliosis was observed post one month after intravitreal injection of AAV2-Cre compared to intravitreal injection of AAV2-PLAP. Also, slightly RGCs loss was observed post one-month AAV2-Cre injection.
GFAP fluorescence
Cre STDEV: 11.420944, SEM: 4.66258088
PLAP STDEV: 2.25240612, SEM: 1.12620306
P<0.001
Conclusions :
In general, OPTN knock out through intravitreal injection among most of the cells in the retina showed astrogliosis and RGC loss, which demonstrated that OPTN knock out would have a change to the mouse retina, and OPTN could be potentially used as a therapeutic target in normal tension glaucoma.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.