Abstract
Purpose: :
To explore the effects of glial cell line-derived neurotrophic factor (GDNF) on cultures of porcine adult retina.
Methods: :
Full-thickness retinal sheets were isolated from adult porcine eyes and cultured for 5 or 10 days under standard culture conditions with or without GDNF 10ng/µl added to the culture medium. The grafts were analyzed morphologically using hematoxylin and eosin staining, immunohistochemistry, and TUNEL labeling. Retinas derived from normal adult porcine eyes were used as controls.
Results: :
After 5 days in vitro (DIV), cultures not treated with GDNF showed dissolving retinal lamination and large numbers of apoptotic cells in the nuclear layers. Specimens cultured with GDNF displayed the normal laminated morphology with small numbers of apoptotic cells within the nuclear layers. After 10 DIV, the untreated cultures had been reduced to a degenerated cell mass, while the GDNF-cultured specimens retained their morphology with distinguishable nuclear layers. Immunohistochemistry showed enhanced survival of horizontal cells (calbindin) and photoreceptors (recoverin), and preserved Müller cell morphology (vimentin) in GDNF treated explants at both 5 and 10 DIV.
Conclusions: :
The culture process imposes severe traumatic effects on the retinal grafts, such as ganglion cell axotomy, separation from the retinal vasculature and the retinal pigment epithelium (RPE). We have shown that the addition of GDNF to the culture medium attenuates these effects, resulting in enhanced preservation of several retinal neuronal subtypes. The results are important for research on the adult retina in vitro and retinal transplantation experiments where storage time of the donor tissue prior to transplantation is a critical issue.
Keywords: cell survival • transplantation • neuroprotection