Abstract
Purpose: :
To determine whether selected mechanotransduction channels (TRPM2, TRPA1 and TRPC1-6) undergo a level change in normal compared to glaucomatous trabecular meshwork (TM) and whether exposure of selected lipids results in the modulation of the levels of these channels on primary TM cells.
Methods: :
All studies were performed adhering to the tenets of declaration of Helsinki. Western analyses were performed on cadaver donor derived glaucomatous and normal TM tissue (n=10 each; all Caucasian donors; age range 55-83 years) procured from the National Disease Research Interchange, Philadelphia and Lions Eye Bank, Miami, Florida. Primary human TM cells (derived from cadaver donors; age range 55-62 years) were subjected to treatment with select phospholipids. The phospholipids for these experiments were selected based on their prior differential identification in normal but not glaucomatous TM using shotgun lipidomics approach in our laboratory. Western Blot analyses were carried out using commercial antibodies to mechanotransduction channels (TRPM2, TRPA1 and TRPC1-4 and 6) that were found in the TM by genomic analyses (from GEO database confirmed with RT-PCR analyses).
Results: :
We found changes in the levels for TRPM2, TRPC3 and TRPC6 between normal and glaucomatous TM normalized to GAPDH levels. We found level changes in TRPM2, TRPC3 and TRPC3 channels determined by Western Blot analyses in primary human TM cells in response to exposure to select exogenous added Phosphocholine and Phosphoserine in cell culture.
Conclusions: :
Our investigation confirms presence of TRPM2, TRPC1-4 and TRPC6 mechanotransduction channels at protein levels in the human TM. Levels of TRPM2, TRPC3 and TRPC6 undergo a change in glaucoma compared to controls and also on primary TM cells in response to exposure to select exogenously added phospholipids.
Keywords: trabecular meshwork • lipids • proteomics