Abstract
Purpose :
To explore pressure-related effects on Müller cell proteins, vital for retinal homeostasis, in the in vitro adult porcine retina.
Methods :
Retinal explants were dissected from adult porcine eyes and subjected to 0, 10, 30, or 60 mmHg of pressure for 24 or 48h in culture in a pressure chamber. Retinal explants fixed immediately after enucleation were used as controls. Immunohistochemistry was performed using GFAP, GS, CRALBP, and bFGF antibodies. If the normality test passed, one-way ANOVA with Tukey's multiple comparisons test was performed, and the mean and standard deviation (SD) calculated. In the remaining analyzes, Kruskal-Wallis test with Dunn's multiple comparisons test was used to compare groups, with calculations of the median and interquartile range.
Results :
GFAP labeling revealed no difference in fluorescence intensity in any of the pressure groups compared with control retinas after 24 and 48h. In contrast, a higher intensity in GS-labeled sections was found in the 60 mmHg group compared with control retinas after 48h (p<0.01). An increase in intensity was seen in all pressure groups after 48h compared with 24h (0 mmHg p<0.05, 10 mmHg p<0.01, 30 mmHg p<0.01, 60 mmHg p<0.05). In addition, CRALBP labeling revealed a higher intensity in the 10, 30, and 60 mmHg groups after 48h compared with controls (10 mmHg p<0.05, 30 mmHg p<0.05, 60 mmHg p<0.05). An increase in intensity was found in the 0, 10, and 30 mmHg groups after 48h compared with 24h (0 mmHg p<0.0001, 10 mmHg p<0.0001, 30 mmHg p<0.0001). A lower intensity of bFGF-labeling was present in the 0, 10, and 30 mmHg groups after 24h (0 mmHg p<0.0001, 10 mmHg p<0.01, 30 mmHg p<0.01) and in the 0 and 10 mmHg groups after 48h compared with control retinas (0 mmHg p<0.05, 10 mmHg p<0.05). A decrease in intensity was found in the 10 mmHg group after 48h compared with 24h (10 mmHg p<0.0001).
Conclusions :
Müller cell homeostatic proteins GS, CRALBP, and bFGF react in response to pressure changes within the adult in vitro retina, while no such reaction is present regarding GFAP, which is considered the hallmark of retinal injury. These results have a bearing on IOP elevation related to glaucoma pathology.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.