RT Journal Article
SR Electronic
T1 Axonal Injury Alters Alternative Splicing of the Retinal NR1 Receptor: the Preferential Expression of the NR1b Isoforms Is Crucial for Retinal Ganglion Cell Survival
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 8278
OP 8291
DO 10.1523/JNEUROSCI.18-20-08278.1998
VO 18
IS 20
A1 Michael R. Kreutz
A1 Tobias M. Böckers
A1 Jürgen Bockmann
A1 Constanze I. Seidenbecher
A1 Bettina Kracht
A1 Christian K. Vorwerk
A1 Jens Weise
A1 Bernhard A. Sabel
YR 1998
UL http://www.jneurosci.org/content/18/20/8278.abstract
AB Cellular-specific splicing of the retinal NMDAR1 receptor (NR1) and expression of NMDAR2 receptor (NR2) subunits in response to optic nerve injury was investigated by in situ hybridization in adult rats. A controlled optic nerve crush led to a clear alteration in the expression of alternatively spliced NR1 variants in the retinal ganglion cell layer (GCL). The NR1–2b and NR1–4b isoforms were preferentially expressed between 2 d and 1 week after injury, whereas expression for all other isoforms remained either unchanged or decreased to barely detectable levels within 4 weeks. Cellular silver grain density for NR2 subunits also declined in the GCL after trauma. To directly test the hypothesis that NR1b expression is crucial for cell survival after axonal trauma, we administered intraocularly an antisense oligonucleotide against the NR1b isoform 2 and 3 d after injury. This led to a drastic loss of retrogradely labeled retinal ganglion cells (RGCs). Antisense targeting clearly reduced retinal NR1 protein levels, as judged by Western blot analysis, but had no effect on the cell number in control retinas. These findings point toward injury-specific changes in alternative splicing of the NR1 receptor, which are crucial for the survival of RGCs after partial axonal trauma. We therefore propose that this reflects an adaptive, rather than a pathogenic, cellular response to neurotrauma.