Abstract
Purpose: :
Mesenchymal stem cells (MSC) can differentiate into a variety of cell types, and MSC-epithelial transdifferentiation has been shown in vitro. Regeneration of the ocular surface using transplanted MSC has been successful in animal models. In humans this treatment may mitigate many of the disadvantages associated with limbal stem cell transplantation for severe ocular surface disease. However it is crucial to first establish the potential of MSC to differentiate into corneal epithelial cells (CEC).
Methods: :
A heterogeneous population of MSC was extracted from human foetal liver. Single random isolates from the heterogeneous MSC population were clonally expanded. These clonal MSC were then stimulated in specific medium to transdifferentiate into CEC. Cell morphology was analyzed by light microscopy. Limbal stem cell (LSC) markers (cytokeratins14 & 19, ABCG2, vimentin and P63) and terminally differentiated CEC (cytokeratin3/12, E-cadherin, connexin43) were analyzed by flow cytometry and qPCR.
Results: :
Some, MSC clones exhibited complete transdifferentiation whereas others retained their MSC phenotype. The transdifferentiated MSC expressed both LSC and CEC markers.
Conclusions: :
Human MSC can transdifferentiate into LSC and CEC in vitro. LSC and CEC appear to only be generated by specific MSC sub-populations. Pre-selection of MSC sub-populations before transplantation onto the ocular surface may expedite corneal regeneration.
Keywords: cornea: basic science • flow cytometry