Abstract
Purpose :
This study was designed to examine changes in retinal populations as a result of treatment with PNU-282987.
Methods :
Male and female 129/SvJ wild-type mice (3 to 6 months) were used for this research. Animals were treated bilaterally daily for 7 or 28 days with PBS eyedrops containing 1 mg/mL BrdU and 1 mM PNU-282987 in experimental groups. After treatment, the retinas were removed and cells were isolated. Cells were then processed for flow cytometry analysis using antibodies against BrdU and Ki67 to identify mitotically active and proliferating cells, in addition to various retinal cell markers. The average percentage of each retinal population before and after PNU-282987 was calculated using FlowJo v10 and shown as mean±SD. Averages were compared using a two-tailed unpaired T test with Welch’s correction using GraphPad Prism v9.5 with an n=2 for all experiments.
Results :
The first experiments were designed to examine how PNU-282987 changed the populations of retinal neurons. Thy1.2+ RGCs increased from an average of 15.5%±0.35 cells under the control to 28.3% (p<0.001) after 7 days, to 34.6% after 28 days of treatment (p<0.001). Similarly, vimentin+ Müller glia cells increased from 5.86%±0.08 cells under control conditions to 23.3% (p<0.001) after 7 days of PNU-282987, and to 15.8% (p<0.001) after 28 days. When examining rhodopsin+ photoreceptors, PNU-282987 had no effect these numbers after 7 days but the percentage of rhodopsin+ photoreceptors significantly increased by 33.4% (p<0.01) after 28 days of treatment. In other experiments, markers were used to detect proliferating and mitotic cells. Thy1.2+ BrdU+ RGCs increased from 1.72%±0.42 (p=0.0023) after 7 days to 7.73% after 28 days of treatment (p<0.0001). Similarly, Thy1.2+ Ki67+ RGCs increased from 3.31%±0.21 (p<0.0001) at 7 days of treatment to 5.57% (p<0.0001) after 28 days. Vimentin+ BrdU+ Müller glia increased from 3.40%±0.82 (p=0.0023) at 7 days to 7.15% (p<0.0001) at 28 days of treatment. The largest increase in vimentin+ Ki67+ Müller glia was seen after 7 days (10.10%±0.04; p<0.0001) compared to 6.56% at 28 days of treatment (p<0.0001). Finally, rhodopsin+ BrdU+ photoreceptors increased from 3.31%±0.06 (p<0.0001) after 7 days to 5.90% after 28 days of treatment (p<0.0001).
Conclusions :
Results from this study support the hypothesis that PNU-282987 can induce neurogenesis in the adult murine retina.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.