Abstract
Purpose :
Trabecular meshwork (TM) regulates aqueous humor outflow and intraocular pressure (IOP) through extracellular matrix (ECM) turnover. Just like any other cell, TM cells communicate with their surroundings. Primary cilia are specialized organelles that may play an important role in that communication. The importance of primary cilia is observed in a group of disorders termed “ciliopathies”. The role of primary cilia in helping TM to communicate with their surrounding in terms of ECM and vice versa remains largely unknown.
Methods :
Cilia positive cells and ciliary lengths (immunochemically using anti-ARL13b antibody) were compared among cultured human primary normal (NTM) and glaucomatous TM (GTM) cell strains and tissues (n=3). Effects on different ECM proteins production and secretion were studied after targeting TM cilia using chemical agents, and siRNA and CRISPR/Cas9 against intraflagellar genes. Samples were analyzed using PCR, western immunoblotting and ELISA. In addition, cells were cultured on different ECM substrates to study the effect on primary cilia.
Results :
Cultured GTM cell strains appear to have longer primary cilia as compared to NTM. Disrupting cilia affect signaling and extracellular matrix synthesis in TM. Cells respond to their extracellular environment by altering their primary cilia length/composition.
Conclusions :
The differences among primary cilia on GTM vs NTM cell strains, involvement of primary cilia in ECM production, and dynamic interaction of ECM with primary cilium suggest a prominent role of primary cilia in TM function and potential involvement in glaucoma pathophysiology.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.