Abstract
Purpose :
Establish a glaucoma animal model. The objective of this project is to determine if Gli1 positive cells contribute to the POM and anterior eye structures by using an inducible Gli1-CreERT2;tdTomatoflox (Gli1-tdTomato) mouse model to serve as a probe for anterior eye development. Pitx2, FOXC1, and FOXC2 are critical for anterior eye development. A second objective is to establish that FOXC1, FOXC2, and Pitx2 are expressed in the Gli1 positive cells.
Methods :
Gli1-tdTomato expressing mice were induced at different stages with tamoxifen. Eyes were examined that were induced E13.5, P3, P30 and sacrificed several days to weeks later. Mouse tissues were fixed and prepared for frozen or paraffin sectioning. Tissue antigen retrieval was done using citric acid buffer. Indirect immunohistochemistry for FOXC1, FOXC2, and Pitx2 was completed. Some samples were counterstained with phalloidin. Sections were analyzed with confocal microscopy for spatial distribution of the Gli1+ labeled cells and FOXC1, FOXC2, and Pitx2.
Results :
In Gli1-tdTomato mice induced on E13.5, P7, and P30, the POM and anterior angle of the eye, eyelids and optic nerve were labeled several days to 3 weeks later. In contrast, the cornea, lens and sclera did not have positive cells for Gli1. Expression levels for FOXC1, FOXC2, and Pitx2 were generally higher in mice harvested at younger ages. After postnatal day 30, the expression decreased with little to no expression of FOXC1 and FOXC2 while Pitx2 expression remained relatively constant in anterior angle tissues.
Conclusions :
This inducible Gli1-tdTomato mouse model may be an excellent system for determining the role of periocular mesoderm in anterior eye development. These results provide evidence that POM cells are contributing to the development of the anterior angle tissues and may be a good target to develop a glaucoma mouse model.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.