Abstract
Abstract: :
Purpose: The aim was to investigate the morphology of fetal GFP transgenic pig retinal progenitor cells integrated into the normal adult pig retina. Methods:Fetal GFP transgenic pigs were sacrificed at 60 days gestation. Neurosensory retinae (excluding the optic nerve head and ciliary marginal zone) were surgically removed and minced. Retinal tissue was subjected to repeated cycles of collagenase (type 1, 0.1%) digestion and then seeded into either uncoated or laminin–treated culture plates in Neurobasal media with B–27 and 20 ng/ml EGF. The cells were expanded for 30–90 days in culture, and then transplanted subretinally to adult Danish domestic pigs with retinal photocoagulation lesions. The pigs were sacrificed at intervals ranging from one to five weeks post–grafting. The eyes were examined for endogenous GFP. Results: The fetal retinal pig cells were found in the subretinal space, as well as in the RPE and the retina. Cells in the subretinal space appeared as clusters of mostly immature–looking cells, although some cells showed bipolar profiles. In the RPE, the grafted cells formed an epithelium–looking layer consisting of only one layer of GFP cells. In the retina, GFP cells were found mostly in the inner layers, but sending long slender processes spanning through the entire retina. GFP cells were often found in close contact with each other seemingly establishing contact via their multiple processes. Conclusions: Our results show that pig fetal GFP retinal progenitor cells can mature in an adult pig retina environment. The grafted cells displayed morphologies resembling mature neurons, however the functional significance of the findings needs to be further evaluated.
Keywords: transplantation • plasticity • immunohistochemistry