UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Does GDNF exert its neuroprotective effects on photoreceptors in the rd1 retina through the glial glutamate transporter GLAST?

Delyfer, MN; Simonutti, M; Neveux, N; Leveillard, T; Sahel, JA; (2005) Does GDNF exert its neuroprotective effects on photoreceptors in the rd1 retina through the glial glutamate transporter GLAST? Molecular vision , 11 677 -687. Green open access

[thumbnail of Delyfer_does_GDNF_MV_2005.pdf]
Preview
PDF
Delyfer_does_GDNF_MV_2005.pdf

Download (243kB)

Abstract

PURPOSE: We previously demonstrated that exogenous glial cell line-derived neurotrophic factor (GDNF) induces histological and functional protection of photoreceptors in the retinal degeneration (rd1) mouse model. The mechanisms underlying such neuroprotection remain elusive. In parallel to this work, we provided evidence for the occurrence of glutamate-mediated excitotoxic phenomena contributing to rod photoreceptor death in the rd1 retina in the companion paper. In the present study, we investigated whether, as demonstrated in other models, GDNF could exert its neuroprotective effect on photoreceptors through Muller glial cells (MGC) by promoting the expression of the glial L-glutamate/L-aspartate transporter (GLAST), an endogenous neuroprotective mechanism against glutamate-mediated excitotoxicity. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to compare the mRNA expression levels of GDNF receptors between rd1 and wild-type mouse retinas as well as between MGC and mixed retinal cell cultures. Recombinant GDNF was applied to pure MGC cultures, to rd1 retinal organ cultures and injected subretinally into rd1 mouse eyes. GLAST expression following GDNF treatment was measured by RT-PCR, immunoblotting and immunohistochemistry. Free glutamate and glutamine levels were quantified in rd1 retinas after GDNF or control treatment using an amino acid analyzer. RESULTS: mRNA expression studies of GDNF receptors, GFRalpha-1 and Ret, demonstrated that GDNF receptors were not exclusively expressed by the degenerating photoreceptor cells but mainly by MGC. Exogenous GDNF application to MGC cultures, rd1 mouse retinal explants and in vivo rd1 mouse retinas increased the expression of GLAST by 48% in retinal explants (p<0.005) and by 25% in vivo (p<0.0005). GLAST protein expression in MGC was particularly increased around degenerative photoreceptors. Free glutamate and glutamine levels in the rd1 retina were not significantly modified by exogenous GDNF. CONCLUSIONS: Our data suggest that, in the rd1 mouse retina, GDNF neuroprotective effect on photoreceptors can be mediated indirectly through the activation of MGC. We demonstrate that injection of recombinant GDNF enhances the expression of GLAST and more particularly around the degenerating photoreceptors. Since we failed to demonstrate that GDNF decreases free glutamate levels, we could not ascertain whether GDNF promoted photoreceptor-survival via an increase of glutamate uptake and, therefore, a change in glutamate distribution

Type: Article
Title: Does GDNF exert its neuroprotective effects on photoreceptors in the rd1 retina through the glial glutamate transporter GLAST?
Open access status: An open access version is available from UCL Discovery
Publisher version: http://www.molvis.org/molvis/volume11.html
Language: English
Additional information: This work is licensed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivativeWorks 3.0 license. You are free to share (copy, distribute and transmit the work), but you must attribute the author, you may not use this work for commercial purposes and you may not alter, transform, or build upon this work and distribute any derivative works you create under a similar license
Keywords: Eye, Immunohistochemistry, Methods, Mouse, Mouse retina, Photoreceptor, Photoreceptors, Retina, Retinal degeneration, Rod
UCL classification: UCL
UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Ophthalmology
URI: https://discovery.ucl.ac.uk/id/eprint/40012
Downloads since deposit
122Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item