Examining the Effect of Cell Culture Microenvironment on Stem Cell Shape and Developmental Potential

Abstract

The cell culture microenvironment plays an important role in controlling cell shape and gene/protein expression. Conventional two dimensional (2D) cell culture provides an unnatural microenvironment for cell growth and causes cells to spread out thinly over the substrate. This change in cell shape leads to abnormal expression of genes compared with cells in vivo due to significant re-organisation of the cytoskeleton.
Recent developments in three dimensional (3D) cell culture allow in vitro cell culture to recreate similar 3D growth conditions a cell would be exposed to in vivo. 3D culture allows cells to maintain their more natural 3D shape which in turn leads to cells expressing more in vivo like levels of proteins compared to conventional 2D cell culture. This is a fundamental issue that influences the majority of cultured cells, including specialised cell types such as stem cells.
Stem cells are located within niches in the body. Stem cells grown in vitro are therefore far removed from their natural microenvironment. With the use of 3D cell culture, we can to recapitulate the in vivo niche and enhance the stem cell phenotype. By changing the shape of the cell using 3D cell culture, we alter protein expression to a more in vivo like state and consequently affect the developmental potential of stem cells. We show that culture of pluripotent stem cells in a 3D microenvironment leads to not only a cell shape change (acquiring a 3D morphology) but that this shape changes leads to an increased developmental potential compared with cells grown in conventional 2D culture. Our data also indicate that the protein ROCK may be involved both in the signalling process in all shape changes and in the maintenance of the new 3D phenotype.