Abstract
Purpose :
To develop a novel method to enhance the differentiation of rat retinal müller cells to photoreceptor cells and explore the mechanism of signaling pathway , thus providing a valuable tool for treating retinal degeneration.
Methods :
Retinal stem cells were dedifferentiated from rat Müller glial cells,then transfected with lentivirus PGC-FU-OTX2-EGFP, empty lentivirus PGC-FU-EGFP,or no transfection randomly. In addition,the retinal stem cells were transfected with Crx siRNA or Nrl siRNA or treated with Wnt/β-catenin signaling antagonist, Dkk-1. The retinal stem cells were induced to differentiate for 3 days,then were injected into the subretinal space of adult MNU-treated rats. The population of differentiated cells and photoreceptors were assessed by immunofluorescence, the expression levels of Otx2,Crx,Nrl and β-catenin were detected using quantitative PCR and Western blotting. ERG of the retinas of rats were performed. Additionally, the apoptosis of retinal cells were eventually detected with TUNEL analysis.
Results :
The proportion of photoreceptor cells differentiated from Otx2-tranfected stem cells was significantly higher than that of controls. Knockdown of Crx or Nrl inhibited, while Wnt promoted, the differentiation into photoreceptors cells.Otx2 promoted the expression of Crx and Nrl and activated by the Wnt/β-catenin pathway. By 2 weeks after subretinal injection, GFP-expressing transplanted cells integrated into the host retina, forming structures similar to the outer nuclear layer,expressed a photoreceptor-specific marker, manifested by a subtle increase in the a-wave amplitude using scotopic electroretinography,indicating that rod photoreceptor function was partially restored in the MNU-treated rats.Furthermore, few positive cells in the TUNEL staining and no teratoma formation was observed in the recipient retina.
Conclusions :
OTX2 promotes the differentiation of Müller cells-derived retinal stem cells into retinal photoreceptor cells by activating Wnt signaling in vitro and in vivo.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.