Expression of Epithelial Membrane Protein 2 (EMP2) in Stem Cells

Abstract

 

Purpose:

 

Epithelial membrane protein-2 (EMP2) is a tetraspan protein that has been shown to regulate surface expression of integrins. EMP2 has been found in localized regions of the body, including the eye. In this study, we set out to see if EMP2 is present in stem cells.

 

Methods:

 

The human embryonic stem cells (hESC) line H9, human bone marrow derived - mesenchymal stromal cells (MSC), and the ARPE-19 cell line were cultured and used in this study. Quantification of EMP2 expression was determined with immunohistochemistry and Western Blot analysis. Immunohistochemistry and Western Blot analysis for EMP2 detection was performed with an antibody against EMP2. F-actin was also identified and labeled in immunohistochemistry with phalloidin.

 

Results:

 

Immunohistochemistry demonstrated that EMP2 is expressed in undifferentiated hESCs, undifferentiated MSCs and ARPE-19 cells. EMP2 was also found to be expressed in hESC that were 20 days into the differentiation pathway toward retinal pigment epithelium. Western Blot analysis confirmed that EMP2 is present and expressed in MSC and ARPE-19 cells.

 

Conclusions:

 

EMP2 is known to exist in the eye, however, these findings show that EMP2 is also highly expressed in undifferentiated embryonic stem cells and mesenchymal stromal cells.  

 

Keywords: gene/expression • immunohistochemistry • protein structure/function