Abstract
Purpose :
Melanocyte is a potential niche component for limbal epithelial stem cells (LESCs). The aim of this research is to investigate its role in modulating proliferation and differentiation of LESCs.
Methods :
Human corneal limbal sections and conjunctival sections were stained with Melan-A to identify the distribution of melanocytes in human ocular surface. Human limbal epithelial cells were clone-cultured and melanocytes were purified from human epidermal cells. The resulting co-cultures were examined for the ability of melanocytes to support the growth of limbal epithelial cells in colony-forming capacity, maintenance of limbal epithelial stem/progenitor cell markers, and gene expression levels of factors that correlated to proliferation and differentiation and stratified epithelial cell sheet formation.
Results :
Melan-A was expressed in the basal layer of limbal epithelium and conjunctival epithelium, neighbouring p63+ epithelial cells. The staining of the limbal epithelial cells co-cultured with melanocyte showed a higher intensity of the limbal stem cell marker ΔNp63 than that in the control group. Moreover, real-time PCR analysis revealed that compared with the common expression of EGF etc., the limbal epithelial cells showed a higher expression level of PCNA, K12 and a higher expression level of β-catenin and hes1. The limbal epithelial cell sheets with melanocytes stratified well, resembling the in vivo constructs of cornea and limbus.
Conclusions :
Melanocytes had the ability to support the proliferation and differention of limbal epithelial cells, suggesting their roles in maintaining the ocular surface. And this effect may partially through activation of Wnt and Notch signaling pathway.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.