Myocilin expression in the eye and blood of zebrafish

Abstract

Purpose : Myocilin is a matricellular protein present in ocular structures and involved in glaucoma. Both its normal function and the pathogenic mechanism remain uncharacterized, but recently we have demonstrated its presence in human blood serum. The main purpose of this study was to characterize the expression of myocilin in the eye and blood of zebrafish.

Methods : Histological sections and blood smears of adult fishes were used for fluorescent immunohistochemistry using an IgY anti-myocilin antibody raised against a synthetic human peptide. The specificity of the signal was evaluated by antibody blocking with the immunogen peptide.

Results : Myocilin was detected in ocular tissues such as the non-pigmented ciliary epithelium, iris vessels and stroma, corneal endothelium and retinal ganglion cell layer. Myocilin was also identified in erythrocytes and leukocytes. Peptide blocking suppressed these signals, supporting their specificity.

Conclusions : To the best of our knowledge, this is the first study of myocilin expression in zebrafish. The observed ocular expression pattern is similar to humans, supporting that zebrafish can be used as a model to study myocilin. The results also support our previous finding of myocilin in blood and its putative role as a plasma matricellular protein.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.