Morphological evaluation of retinal ganglion cells expressing the L132C/T159C ChR2 mutant transgene in young adult cynomolgus monkeys

摘要

To characterize recombinant AAV2(rAAV2)-mediated expression of L132 C/T159 C ChR2 mutant in retinal ganglion cells(RGCs)of young adult cynomolgus monkeys, rAAV2 vectors carrying a fusion construct of the ChR2 mutant and GFP(ChR2-GFP) were delivered to the vitreous chamber by intravitreal injection. Expression patterns of the ChR2 mutant in RGCs were examined by immunohistochemical methods three months after injection. The RNA-binding protein with multiple splicing(RBPMS) was used as an RGC specific marker to differentiate RGCs from other retinal neurons and non-neuronal cells. The numbers of RBPMS+and GFP+ double-labeled RGCs in the central foveal varied with the eccentricity. The expression peaked within 100 μm from the edge of the foveola and drastically decreased to a single superficial RGC layer approximately 300 μm from the edge. On average,the ratio of the double-labeled RGCs versus RBPMS+ RGCs approached 0.32±0.15(n=14 fields) at the central foveal region(0.1 to 0.53 mm). We observed that the ratio reached 0.78±0.16(n=21 fields) at peripheral retinal locations(eccentricity >7 mm). This investigation demonstrates that RBPMS could serve as a valuable RGC specific marker for future investigations in this field.