Abstract
Abstract: :
Purpose: To partially characterize the factors affecting survival of retinal ganglion cells (RGCs) in vitro. Methods: Retinas from adult pigs were dissociated and seeded under six different conditions: 1) chemically defined medium (CDM) onto glass coverslips treated with laminin/poly-lysine, 2) CDM + brain-derived neurotrophic factor (BDNF 10 µg/ml), 3) CDM on confluent pig retinal Müller cell (RMC) monolayers, 4) CDM on fixed RMC, 5) CDM on 1 day RMC and 6) CDM + conditioned medium obtained from the supernatant of confluent RMC. After six days in vitro, coverslips with cultured cells were processed for immunohistochemistry using anti-neurofilament (NF) 68 kDa subunit monoclonal antibody or NF 200 kDa subunit polyclonal antibody to label RGCs. RGCs survival, size and neuritic morphology were characterised in the different conditions. Results: Pig RGC survival was increased with respect to control conditions (defined as 100%) when cultures were grown on confluent RMC substrates (110.4 3.4 %) or using RMC conditioned medium (116.7 4%). An increase in the mean area of RGC somas was also observed in response to both treatments. Percentage of neurite-bearing cells increased from 59.6 8.8 % in controls, to 99.5 0.4% with cells grow on confluent RMC, and 93.6 2 % in RMC conditioned medium. Neurite length was significantly increased in both conditions. BDNF did not significantly affect RGC survival (104.6 4.2 %) but produced significant increases in soma size (120.8 8.2%), in the number of neurites per cell, and in neurite length. Conclusion: RMC produce some important factors involved in neuroprotection of RGCs. BDNF does not affect RGC survival but modifies size distribution and neuritic morphology of RGCs, albeit to a lesser extent to that observed for RMC. Supported by grants from Univ. País Vasco, Gob. Vasco, MEC PM97-0047 and European Community.
Keywords: 415 ganglion cells • 479 Muller cells • 489 neuroprotection