Abstract
Purpose :
Exosomes are now widely accepted as signaling carriers supporting inter tissues communication. Regarding the ocular drainage system we recently reported that non-pigmented ciliary epithelium (NPCE) derived exosomes can attenuate normal trabecular meshwork (NTM) canonical Wnt signaling. These signaling effects were detected using both NPCE and NTM cell lines. The present study aim was to validate our results in NPCE and NTM primary cells.
Methods :
Exosomes were extracted from Primary Human NPCE (NPCEp, ScienCell® Catalog #6580) or human NPCE cell line cells (NPCE, kindly donated by Professor Coca-Prados, Yale USA) grown in medium with exosomes depleted serum. Exosomes were characterized using tunable resistive pulse sensing (TRPS), transmission electron microscopy (TEM) and specific exosomes markers (Exo-Check antibody array). Exosomes from both sources were incubated for different time with primary NTM cells (TM-123 kindly donated by Prof. D. Stamer, Duke, USA). NTM cells proteins were extracted and analyzed using western blot analysis.
Results :
NPCEp derived exosomes are significantly smaller than NPCE derived exosomes (80nm vs 114nm respectively). NPCEp cells and NPCE cell line derived exosomes had similar effect on selected canonical Wnt signaling protein expression when incubated with primary NTM cells. In both types of cells exosomes caused a significant decrease in pGSK3b and b-catenin expression at 1h and 2h after incubation with NTM cells. Interestingly, in order to achieve the same effect, NPCEp exosomes concentration according to their protein content was one fifth of NPCE cell line derived exosomes.
Conclusions :
Using NPCE and NTM cell lines as a model for signaling delivery between the aqueous humor producing cells and the aqueous humor draining cells is supported by the present primary cells findings. The NPCEp derived exosomes effect was significantly larger suggesting possibly different exosome cargo content.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.