Lookup NU author(s): Dr Sanja Bojic,
Dr Dean Hallam,
Dr Ali Ghareeb,
Dr Rachel Queen,
Dr Gustavo Figueiredo,
Professor Francisco Figueiredo,
Professor Majlinda Lako
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
One of the main challenges in limbal stem cell (LSC) biology and transplantation is the lack of definitive cell surface markers which can be used to identify and enrich viable LSCs. In this study, expression of 361 cell surface proteins was assessed in ex vivo expanded limbal epithelial cells. One marker, CD200 was selected for further characterisation based on expression in a small subset of limbal epithelial cells (2.25±0.69%) and reduced expression through consecutive passaging and calcium induced differentiation. CD200 was localised to a small population of cells at the basal layer of the human and mouse limbal epithelium. CD200+cells were slow cycling and contained the majority of side population and all the holoclone forming progenitors. CD200+ cells displayed higher expression of LSCs markers including PAX6, WNT7A, CDH3, CK14, CK15 and ABCB5 and lower expression of Ki67 when compared to CD200- . Downregulation of CD200 abrogated the ability of limbal epithelial cells to form holoclones, suggesting an important function for CD200 in the maintenance and/or self-renewal of LSCs. A second marker, CD109 which was expressed in 56.29±13.96% of limbal epithelial cells, was also found to co-localise with ΔNp63 in both human and mouse cornea, albeit more abundantly than CD200. CD109 expression decreased slowly through calcium induced cell differentiation and CD109+ cells were characterised by higher expression of Ki67, when compared to CD109- subpopulation. Together our data suggest that CD200 expression marks a quiescent population of LSCs with holoclone forming potential, whilst CD109 expression is associated with a proliferative progenitor phenotype.
Author(s): Bojic S, Hallam D, Alcada N, Ghareeb A, Queen R, Pervinder S, Buck H, Lange AA, Figueiredo G, Rooney P, Stojkovic M, Shortt A, Figueiredo FC, Lako M
Publication type: Article
Publication status: Published
Journal: Stem Cells
Print publication date: 01/11/2018
Online publication date: 29/08/2018
Acceptance date: 09/08/2018
Date deposited: 10/08/2018
ISSN (print): 1066-5099
ISSN (electronic): 1549-4918
Publisher: AlphaMed Press, Inc.
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