Development of Non-Animal-Based Method to Grow Human Embryonic Stem Cells
News Aug 28, 2008
Because of their tremendous potential, hESCs are considered promising sources for future cell therapy to treat diseases such as Parkinson’s disease and diabetes mellitus.
Noboru Sato, an assistant professor of biochemistry, developed the new method, which is not only cleaner and easier to use than conventional methods of culturing hESCs but also results in hESCs whose pluripotency – the potential to differentiate into any of the specialized cells of the body such as neurons, cardiac muscles, and insulin-producing cells – is uncompromised.
Currently in labs worldwide, many researchers grow hESCs on Matrigel-coated culture plates, Matrigel being the trade name for a gelatinous extract, taken from mouse tumor cells, that contains extracellular matrices (ECMs), made up of special proteins. The Matrigel coating provides the scaffolding to which the hESCs first attach and then grow in undifferentiated colonies before differentiating into specialized cells.
“The development of animal-free coating methods for hESCs still remains a major challenge due to the complexity of ECMs and insufficient knowledge about how hESCs control cell-cell and cell-ECM interactions,” explained Sato, who led the research project.
His lab identified a specific signaling pathway, called Rho-Rock, which the hESCs use during colony formation and which plays an important role in physical interactions between hESCs. When the researchers blocked the pathway, they found, as expected, that the normal colony formation of hESCs was considerably impaired. They also found that the hESCs maintained their pluripotency.
“Until now, it was generally assumed that the hESC colony formation was pivotal for maintaining pluripotency,” Sato said. “But we show that pluripotency can be retained independent of close cell-cell contact.”
Prue Talbot, the director of UCR’s Stem Cell Center of which Sato is a member, noted that Sato’s discovery could affect the way embryonic stem cells are grown in the future.
“His work is certainly an important step forward in both understanding signal transduction pathways in stem cells and in the development of an improved methodology for culturing stem cells,” she said.
Original article: Harb et al PLoS ONE 3(8): e3001. doi:10.1371/journal.pone.0003001