Abstract
Abstract: :
Purpose:Previous studies have reported that kainic acid–induced apoptosis of retinal ganglion cells correlates with specific degradation of laminin from the underlying inner limiting membrane by an increased gelatinolytic metalloproteinase activity. This study evaluated the effects of matrix and matrix components on retinal ganglion cell line (RGC–5) growth and viability. Since NMDA excitotoxicity mediates the death of retinal ganglion cells (RGCs) in glaucoma we studied the effects of different inner limiting membrane components on RGC–5 viability in the presence of glutamate. Methods:RGC–5 cells were cultured in media containing 10% fetal calf serum. Viable attached cells were assessed using the neutral red dye uptake assay. Proliferation was quantified by 5’–bromo–2’–deoxyuridine (BrDU) incorporation into RGC–5 cells, immunostaining at 17 hours after plating on laminin and matrigel matrices. Components evaluated included type IV collagen, fibronectin, laminin, and matrigel infiltrated with growth factors. We tested the effect of glutamate on RGC–5 cells grown in the above media in the presence and absence of 5 mM glutamic acid, incubated for 24 hours. Results: Analysis of the BrDU incorporation into RGC–5 cells suggested that matrigel increased growth by accelerating cell proliferation and viability in comparison to laminin. The efficacy of neuroprotection by the different matrix components and matrix itself in the presence of glutamate were as follows: fibronectin 95.87%>Collagen 90.42%>uncoated 89.5%>laminin 77.96%>matrigel 72.34%. Conclusions: These results suggest that matrigel is superior to laminin in promoting RGC–5 attachment and survival. However, it also potentiates glutamate toxicity.
Keywords: extracellular matrix • excitatory neurotransmitters • retinal culture