Abstract
Purpose: :
Corneal endothelial cell dysfunction is a common cause of corneal vision loss. One possible therapeutic approach for such disorders is the proliferation of human corneal endothelial cells, either in vivo or in vitro. Such proliferation is common in vascular and lymphatic endothelium but is not characteristic of in vivo corneal endothelium. However, corneal endothelium is of a separate embryological derivation from vascular or lymphatic endothelium, and the degree of phenotypic similarity between these three cell types is not well characterized. The goal of this study was to assess human primary cultured corneal endothelial cells for expression of cell surface markers involved in vascular and lymphatic endothelial cell proliferation. The presence or absence of these surface proteins may be useful in further characterizing and inducing proliferation of the human corneal endothelium.
Methods: :
Endothelial cells from a three year old human cornea were dissociated and grown in enriched organ culture medium. A Trizol (Invitrogen) RNA extraction was performed to collect total RNA from these cells, and reverse transcription PCR (RT–PCR) was used to assess for the expression of the following markers of vascular and lymphatic endothelial cell proliferation: VEGFR–2, VEGFR–3, LYVE–1, and PECAM–1. Control reactions included beta–actin and RNA from vascular endothelial cell lines known to express the markers studied.
Results: :
Expression of the vascular or lymphatic endothelial cell proliferation markers (VEGFR–2, VEGFR–3, LYVE–1, PECAM–1) was not detected by RT–PCR analysis.
Conclusions: :
These data indicate that human primary cultured corneal endothelial cells do not express the cell surface markers VEGFR–2, VEGFR–3, LYVE–1, or PECAM–1 associated with proliferation in vascular and lymphatic endothelium. This suggests that corneal endothelial cell proliferation occurring under culture conditions utilizes a different mechanism than these other two cell types, and that well–characterized mechanisms of vascular and lymphatic endothelial proliferation may be less promising approaches for inducing corneal endothelial proliferation in vitro or in vivo.
Keywords: cornea: endothelium • proliferation • cornea: basic science