Effects of müller glia on cell survival and neuritogenesis in adult porcine retina in vitro.

PURPOSE To examine the effects of glia-derived and brain-derived neurotrophic factors on survival and morphology of cultured retinal ganglion cells (RGCs) from adult porcine retina. METHODS Adult porcine retinas were dissociated and cultured in different conditions: (1) on laminin- and poly-D-lysine-coated coverslips in chemically defined medium (CDM); (2) on laminin- and poly-D-lysine-coated coverslips in CDM supplemented with brain-derived neurotrophic factor (BDNF); (3) in confluent monolayer cultures of retinal Müller glia (RMG) in CDM; (4) in 1-day cultures of RMG in CDM; (5) in fixed RMG cultures in CDM; and (6) in laminin-poly-D-lysine substrate in conditioned medium obtained from RMG. RGCs were classified on the basis of the size, number of neurites, and length of the neurites, and the survival of the RGCs was assayed after each treatment. RESULTS Confluent RMG substrates and RMG-conditioned medium significantly increased the survival of cultured porcine RGCs. Moreover, these two conditions increased the size of the RGCs and enhanced growth and elongation of the neurite. Addition of BDNF to the culture medium or use of 1-day cultured RMG as a substrate did not modify survival but increased the size, neurite number, and neurite length in the RCGs. CONCLUSIONS These findings demonstrate that factor(s) secreted by RMG exert beneficial effects on survival of adult RGCs and neurite regeneration in vitro and may constitute effective agent(s) for neuroprotection of RGC.