Pressure-Related Effects on Homeostatic Müller Cell Proteins in the Adult Porcine in Vitro Retina

Purpose: To explore early pressure-related effects on Müller cell homeostatic proteins in the in vitro adult porcine retina. Methods: Retinal explants were subjected to 0-, 10-, 30-, or 60-mmHg of pressure for 24 or 48 h in culture. Retinal explants fixed immediately after enucleation were used as controls. Müller cell proteins were evaluated by GFAP, GS, CRALBP, and bFGF immunohistochemistry. Results: GFAP-labeling revealed no differences in fluorescence intensity after 24 or 48 h in any of the pressure groups compared with control retinas. However, a higher intensity was found in the 30- and 60-mmHg groups compared with 0-mmHg counterparts after 24 and 48 h. A higher intensity in GS-labeled sections was found in the 10-and 60-mmHg groups compared with controls and remaining pressure groups after 48 h. Compared with control retinas, CRALBP labeling revealed a higher intensity in the 60-mmHg group after 24 h and in the 10-, 30-, and 60-mmHg groups after 48 h. After 24 and 48 h, a lower intensity was found in bFGF-labeled cells in the 0-, 10-, and 30-mmHg groups compared with controls, while no difference was seen for the 60-mmHg group. Conclusions: Müller cells in the cultured porcine adult retina respond early to pressure by altering the expression of GFAP as well as the homeostatic proteins GS, CRALBP, and bFGF.