Abstract
Purpose :
Oxidative stress plays a cardinal role in the pathophysiology of AMD, and leads to apoptosis of RPE. Adipose tissue derived mesenchymal stem cells (ASCs) may serve as a therapeutic tool to regenerate RPE. Here we evaluated the activity of ASCs when exposed to RPE under oxidative stress in vitro; we assessed their migratory capacity towards injured RPE, and their ability to prevent apoptosis of RPE. We also studied the differentiation potential of ASCs into RPE.
Methods :
Human ASCs were harvested from subcutaneous fat of patients undergoing abdominoplasty. Primary cultures of human RPE cells were subjected to oxidative stress by exposure to 1.5mM hydrogen peroxide (H2O2). Conditioned medium of “stressed” RPE was collected. The migratory capacity of ASCs towards conditioned medium of “stressed” RPE or towards conditioned medium of normoxic RPE was determined by a scratch assay. In order to study the preventive effect of ASCs on apoptosis of RPE, “stressed” RPE were treated with ASCs’ conditioned medium or with standard, non-conditioned medium. H2O2 induced RPE apoptosis was measured by Annexin V/ propidium iodide staining and flow cytomtery analysis. Finally, the differentiation potential of ASCs into RPE was evaluated by culturing ASCs with 10nM nicotine amide.
Results :
ASCs exhibited enhanced migration towards RPE that were subjected to oxidative stress (193%±0.4 increase cells per area, p<0.05). Treatment of “stressed” RPE with ASCs’ conditioned medium prevented H2O2 induced apoptosis (50±0.7% decrease cells number, p <0.05). After two weeks in differentiation medium, ASCs underwent marked morphological changes forming spheroid bodies in culture and upregulating early eye field markers (PAX6 2.2±0.1, RX 2.1±0.8, BF1 4.7±0.7, NestinA 2.3 ±0.38 folds).
Conclusions :
ASCs migrate towards RPE under oxidative stress and reduce H2O2 induced apoptosis of RPE. Moreover, ASCs demonstrate a differentiation potential into RPE evident by a morphological change and upregulation of eye field markers. These data may imply to a therapeutic potential of ASCs in regenerating RPE.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.