Abstract
Purpose :
To compare the integrin a3, a5, and b1 expression of iPS-derived human RPE (iPS-RPE) and ARPE-19 cells and test the efficacy of several known strategies to boost up iPS-derived human RPE integrin expression.
Methods :
Three iPS-derived human RPE cell lines were generated according to Yamanaka protocol. Expression of integrin a3, a5, and b1 on passage #2-4 iPS-RPE cells were determined using flow cytometry and compared with the expression of integrins on ARPE19 cells. Several strategies were also applied to preserve and/or boost up the integrin expression of the iPS-RPE, including: (1) Incubation with glucocorticoids (cortisol: 10 nM -10 mM; dexamethasone: 100 nM-500 nM) for 12 days; (2) Incubation with extracellular matrix molecules (laminin, 1 ug/ml and fibronectin, 20 ug/ml); (3) Different harvesting techniques (trypsinization vs. scraping), and (4) Plating cells on different matrices (Matrigel®, non-treated tissue culture plastic and human Bruch’s membrane). ARPE-19 cells treated similarly was taken as control.
Results :
Integrin a3, a5, and b1 expression of all three iPS-RPE cell lines were significantly lower than ARPE-19 cells. Glucocorticoids did not increase the a3, a5, and b1 integrin expression of iPS-RPE cells; however, cortisol and dexamethasone at concentrations higher than 100 nM induced mild increase in a-5 expression of ARPE-19 cells. Overnight incubation of iPS-RPE and ARPE-19 cells in the presence of laminin and fibronectin or adding soluble laminin and fibronectin to their culture media did not alter the integrin expression. Harvesting both iPS-RPE and ARPE-19 cells with trypsinization resulted in better preservation of a3, a5, and b1 integrins. iPS-RPE cells plated on Matrigel® gradually expressed more a-3 integrin; however, plating them on human Bruch’s membrane significantly downregulated the a-3 integrin expression.
Conclusions :
Integrin a3, a5, and b1expression of iPS-RPE cells is significantly lower than ARPE-19 cells. This correlates with their lower reattachment and survival rates on human Bruch’s membrane. Strategies should be developed to increase integrin expression of iPS-RPE prior considering to transplant these cells for repairing the damaged human RPE matrix.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.