Abstract
Purpose :
To generate and characterize a mouse model for PRCD-deficiency in humans.
Methods :
Targeted deletion of Prcd in mice was obtained by homologous recombination in embryonic stem cells. Characterization of retinal structure was obtained by light microscopy and by electron microscopy through retinal sections. Characterization of retinal function was obtained by electroretinography (ERG). Immunohistochemistry was performed to measure the phagocytosis of photoreceptor outer segment (POS) discs by the retinal pigment epithelium (RPE).
Results :
Prcd- knockout (ko) mice presented with progressive retinal degeneration, starting at 20 weeks of age and onwards. This process was reflected by a significant and progressive reduction of both scotopic and photopic ERG responses, and by thinning of the retina, and specifically of the outer nuclear layer, indicating photoreceptor loss. Electron microscopy revealed severe damage of the photoreceptor layer and loss of POS in the Prcd-ko retina. In 5-weeks old Prcd-ko mice, phagocytosis of POS discs by the RPE was severely impaired.
Conclusions :
Prcd-ko mice serve as a good model for retinitis pigmentosa caused by PRCD mutations in humans. Impaired phagocytosis of POS discs in Prcd-ko mice implies that PRCD is involved in this process. This study has important implications for understanding the function of PRCD in the retina, as well as for future development of treatment modalities for PRCD-deficiency in humans.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.