UC Irvine

Purpose

To investigate different in vitro model systems for retinal progenitor cell (RPC) isolation and expansion.

Methods

RPCs were isolated from embryonic day (E) 17 Long Evans rat retinas. Three different culture media: (1) modified serum free defined media (2) serum-containing media and (3) embryonic stem cell (ES)-conditioned media were used for RPC isolation and long term expansion. Expression of various cellular markers and cell morphologies were compared among the three culture systems at different passages by immunostaining and confocal microscopy.

Results

All three culture systems could maintain RPCs as nestin-positive cells (78-87%) after long-term in vitro expansion. However, RPCs appeared to proliferate faster in the serum-free culture system. The ES-conditioned media provided the best RPC survival. Cells appeared smaller at early passages compared with later passages. This morphology change occurred at P9-P10 in the serum-free medium, and at P5-P6 in the other two culture systems.

Conclusions

The serum-free medium may be superior for preventing RPC differentiation during expansion.