Extracellular miR-6723-5p could serve as a biomarker of limbal epithelial stem/progenitor cell population

BACKGROUND: Dysfunction or loss of limbal stem cells can result in limbal stem cell deficiency (LSCD), a disease that cause corneal opacity, pain, and loss of vision. Cultivated limbal epithelial transplantation (CLET) can be used to restore stem cell niche homeostasis and replenish the progenitor pool. Transplantation has been reported with high success rate, but there is an unmet need of prognostic markers that correlate with clinical outcomes. To date, the progenitor content in the graft is the only parameter that has been retrospectively linked to success. METHODS: In this study, we investigate extracellular micro RNAs (miRNAs) associated with stem/progenitor cells in cultivated limbal epithelial cells (cLECs). Using micro RNA sequencing and linear regression modelling, we identify a miRNA signature in cultures containing high proportion of stem/progenitor cells. We then develop a robust RNA extraction workflow from culture media to confirm a positive miRNA correlation with stem/progenitor cell proportion. RESULTS: miR-6723-5p is associated with cultures containing high proportion of stem/progenitor cells, and is detected in the basal layer of corneal epithelium. CONCLUSIONS: These results indicate that miR-6723-5p could potentially serve as a stem/progenitor cell marker in cLECs. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40364-022-00384-2.