Abstract
Purpose:
To determine the direct interaction between the extracellular matrix protein cochlin and the mechanotransducing channel TREK-1 in intraocular pressure regulation
Methods:
TREK-1 mRNA was silenced in the DBA/2J mouse model in an effort to determine its effect on intraocular pressure. A sodium fluorescein dye assay along with a gel expansion assay was implemented to mimic the effect of the cochlin/TREK-1 interaction on trabecular meshwork cell conformation. The interaction was further characterized by a co-immunoprecipitation and the utilization of a yeast - two hybrid system. Patch - clamp whole cell recording was also performed in the presence or absence of cochlin in order to measure TREK-1 channel activity.
Results:
TREK-1 mRNA silencing prevented a cochlin-induced increase in intraocular pressure (IOP). The presence of cochlin and TREK-1 together causes a spatial change in the cells of the trabecular meshwork as demonstrated by the increase of the fluorescein dye and the increase in collagen length in the gel expansion assay. A co- immunoprecipitation further demonstrated the increase of cochlin and TREK-1 specifically under shear stress and ionic stress conditions. The yeast-two hybrid system using a T7 promoter sequence demonstrated direct interaction between the bait (hCochlin) and TREK-1. In addition, cochlin interaction reduced TREK-1 channel currents as demonstrated by whole cell patch clamp recordings.
Conclusions:
The results support the potential interaction occurring between cochlin and TREK-1 under stressful conditions, which in turn may result in extracellular matrix remodeling and an increase in IOP.