Mesenchymal stem cells and corneal regeneration

Mesenchymal stem cells (MSC) are the subject of intensive research for regenerative medicine purposes. MSC can be isolated from a broad range of tissues, allowing use in both autologous or allogeneic stem cell transplantation. Furthermore, these cells are readily bankable and their numbers can be expanded in vitro. MSC possess an impressive functional-repertoire as they are differentiated into a steadily growing number of cell types, including those found in the cornea. However the regenerative abilities of MSC extend beyond differentiation. MSC are able to modulate and supress localised immune responses encouraging graft acceptance and reducing occurrences of GVHD/rejection. Furthermore they are able to encourage regeneration by the host tissue using a multitude of paracrine signalling pathways. MSC have previously been shown to promote corneal wound healing both with and without incorporation into the host tissue. MSC have been found to reside in the limbal and peripheral corneal stroma. Although their role in normal corneal homeostasis and wound healing is unknown there have recently been tantalising glimpses into their potential for substantial corneal regeneration.