Abstract
Purpose::
To investigate whether progenitor cells isolated from human retrolental tissue of persistent fetal vasculature (PFV) differentiate into neuronal elements when transplanted into the host ocular microenvironment.
Methods::
PFV cells have previously been shown to differentiate into mature neuronal cells in culture. PFV cells were pre-labeled with PKH26 tagged with rhodamine and injected into the vitreous of C57BL/6 mice. Animals were sacrificed on days 3, 7, 14, 28 and 56 after which eyes were enucleated and cryosectioned. Immunohistochemical analysis was performed using the following differentiation markers: neural filament, Growth-Associated Protein (GAP)-43, PKC-α, recoverin, GFAP and PECAM (endothelial).
Results::
Transplanted PFV cells were found primarily in the vitreous and were observed at all time points. In most animals, these transplants attached to the lens, and occasionally onto the recipient's retina. On days 28 and 56, cells proliferated from the transplant and formed a narrow bridge-like structure that connected with the host's optic disc. Immunohistochemical analysis verified the absence of GFAP+ astrocytes in the transplant. GAP-43+ axons developed fibers which extended from the transplant, via the bridge-like structure into the recipient's optic disc.
Conclusions::
Human PFV cells isolated in our laboratory can differentiate into neuronal cells in vitro and in vivo. The ability of these differentiated neuronal cells to extend axons into the host's optic disc may indicate their future utility in diseases such as glaucoma where they could replace lost retinal ganglion cells.
Keywords: differentiation • optic disc • retina