Abstract
Purpose:
Lysyl oxidase-like protein-1 (LOXL1) maintains elasticity of connective tissues and natural variants of it show a strong association with the development of pseudoexfoliation syndrome/glaucoma (PEXS/G). LOXL1 is a major component of PEX-material, and the expression of LOXL1 appears to be induced during early stages of PEXS. Here we generated mice with an ocular overexpression of LOXL1 to examine the effects on the ultrastructure of the tissues of the anterior eye.
Methods:
1-3-, and 12-month-old mice with lens-specific transgenic overexpression of murine LOXL1 under the control of the chicken βB1-crystallin promoter and wild-type littermates were analyzed by transmission and scanning electron microscopy. The thicknesses of the zonular fibrils and the basal lamina of the non-pigmented ciliary epithelium were analyzed by morphometry. In addition, the animals were analyzed by funduscopy and intraocular pressure (IOP) readings.
Results:
βB1-crystallin-Loxl1 transgenic mice showed high expression of Loxl1 mRNA in their lenses causing a substantial increase in LOXL1 levels in the aqueous humor. The high amounts of LOXL1 did neither lead to formation of PEX-material nor to an increased IOP. There were no ultrastructural changes neither of the zonular fibers nor of the basal lamina of the non-pigmented ciliary epithelium.
Conclusions:
Higher than normal amounts of LOXL1 do not cause changes in the ultrastructure of zonular fibers or ciliary body. Moreover, they are not sufficient to induce PEXS or PEXG.
Keywords: 597 microscopy: electron microscopy •
519 extracellular matrix •
514 enzymes/enzyme inhibitors