Effect of Stem Cell-Derived Extracellular Vesicles on Damaged Human Corneal Endothelial Cells
Raffaele Nuzzi, Lola Buono, Simona Scalabrin, Marco De Iuliis, Benedetta Bussolati
Abstract
Purpose. Human corneal endothelial cells (HCECs) are essential to visual function; however, since they have limited proliferative capacity in vivo, they are prone to corneal endothelial dysfunction. At present, the only treatment is a corneal transplantation from donor cadavers. Also, due to a global shortage of donor corneas, it is important to find alternative strategies. Recent studies highlight that stem cell–derived extracellular vesicles (EVs) play a relevant role in stem cell-induced regeneration by reprogramming injured cells and inducing proregenerative pathways. The aim of this work is to evaluate whether EVs derived from mesenchymal stem cells (MSC-EVs) are able to promote regeneration of damaged HCECs. Methods. We isolated HCECs from discarded corneas in patients undergoing corneal transplantation or enucleation ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mi>N</a:mi> <a:mo>=</a:mo> <a:mn>23</a:mn> </a:math> patients). Bone marrow mesenchymal stem cells (MSCs) were obtained from Lonza, cultured, and characterized. MSC-EVs were obtained from supernatants of MSCs. In order to establish a valid in vitro damage model to test the regenerative potential of EVs on HCECs, we evaluated the proliferation rate and the apoptosis after exposing the cells to serum-deprived medium at different concentrations for 24 hours. We then evaluated the HCEC migration through a wound healing assay. Results. In the selected serum deprivation damage conditions, the treatment with different doses of MSC-EVs resulted in a significantly higher proliferation rate of HCECs at all the tested concentrations of EVs ( <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"> <c:mn>5</c:mn> <c:mo>‐</c:mo> <c:mn>20</c:mn> <c:mo>×</c:mo> <c:msup> <c:mrow> <c:mn>10</c:mn> </c:mrow> <c:mrow> <c:mn>3</c:mn> </c:mrow> </c:msup> </c:math> MSC-EV/cell). MSC-EVs/cell induced a significant decrease in number of total apoptotic cells after 24 hours of serum deprivation. Finally, the wound healing assay showed a significantly faster repair of the wound after HCEC treatment with MSC-EVs. Conclusions. Results highlight the already well-known proregenerative potential of MSC-EVs in a totally new biological model, the endothelium of the cornea. MSC-EVs, indeed, induced proliferation and survival of HCECs, promoting the migration of HCECs in vitro.