Abstract
Abstract: :
Purpose:Ciliary neurotrophic factor (CNTF) has been shown to promote the expression of bipolar cell markers in developing P0 rat retinal explants. Treatment with CNTF results in an increase in the number of cells expressing bipolar cell markers, with a loss in the population of cells expressing rhodopsin (Z.D. Ezzeddine et al, Development 124, 1055–1067; 1997). We evaluated the survival, migration and differentiation of retinal progenitor cells (RPCs) exposed to CNTF by seeding them onto retinal explants harvested from rd mice. Methods:RPCs were isolated from the retina of P1 EGFP mice and maintained in culture. RPCs were cultured on laminin/Poly–D–Lysine coated flasks and treated with CNTF 20ng/ml. After 2 weeks in culture, the cells were trypsinized and seeded onto C3H rd retinal explants. After 1 week of co–culture with the RPCs, the explants were fixed in 4% paraformaldehyde and cryosectioned for immunostaining. We evaluated survival and migration via GFP expression and stained for markers of bipolar, glial and other mature retinal neurons. Antibodies against PKCα, nestin, GFAP, Calbindin, NF–200, recoverin and rhodopsin were used to determine the differentiation status of RPCs in the diseased retina. Results:Epifluorescence microscopy showed that the RPCs survived and migrated into the diseased retinal explant. The explanted RPCs expressed PKCα and GFAP. There was a down–regulation in the expression of nestin in the RPCs after explantation, suggesting differentiation of the progenitor cells. Conclusion:Our results show that CNTF promotes the differentiation of multipotent progenitor cells into cells expressing bipolar and glial cell markers. The use of rd explants as a model for retinal degenerative diseases provides an excellent system for developing techniques such as cell transplantation for the treatment of these diseases.
Keywords: retinal culture • bipolar cells • retina