Nov. 13, 2014

One remarkable quality of pluripotent stem cells is they are immortal in the lab, able to divide and grow indefinitely under the right conditions. It turns out this ability also may exist further down the development path, with the workhorse progenitor cells responsible for creating specific tissues.

A team from the Morgridge Institute for Research regenerative biology group, led by University of Wisconsin-Madison professor and stem cell pioneer James Thomson, discovered a way to impose an immortal-like state on mouse progenitor cells responsible for producing blood and vascular tissue. By regulating a small number of genes, the cells became "trapped" in a self-renewing state and capable of producing functional endothelial, blood and smooth muscle cells.

David Vereide

The finding, to be published in the December 9, 2014 issue of Stem Cell Reports, points to a potential new approach to developing cells in the lab environment for use in drug screening, therapies and as a basic research tool.

"The biggest takeaway for me is the ability to arrest development of these cells," says David Vereide, a Morgridge fellow in regenerative biology and lead author on the paper. "Normally, these cells are ephemeral and get used up while differentiating into specific cell types, but we found a way to interrupt that."

During development, blood and vascular cells are thought to originate from a progenitor cell known as a hemangioblast. This research project identified and imposed six transcription factors on the cells that allowed hemangioblasts to keep proliferating over multiple generations. Transcription factors are proteins that regulate which genes get turned on or off in a genome.

In this case, the transcription factors act to "keep the lights on" in these cellular factories that kept them dividing and expanding, he says.

One exciting element of this research, Vereide says, is it could greatly improve the efficiency of creating cell types that have research and therapeutic value. Progenitor cells, the "sons and daughters" of stem cells that give rise to specific tissue, are usually the end steps in producing the key building-block cells for the body brain, vasculature, bone, etc.

Visit link:
Morgridge scientists find way to keep the lights on for cell self-renewal

UW-Madison cell and regenerative biology professor James Thomson and his team of scientists recently made new strides in their extensive stem cell research.

Thomson and his team members from the Morgridge Institute for Research conducted tests and experiments on mice to advance their research, according to a UW-Madison news release.

Results from the trials led to a developed method which eternally preserves progenitor cells in their pluripotent stages. In other words, the stem cells, which eventually transform into specific tissues, will forever remain in a phase with the potential to become one of at least 200 different cell types.

Maintaining pluripotent stem cells in a controlled environment enables them to undergo constant reproduction. The cells will cyclically divide and grow to produce working endothelial, blood and smooth muscle cells.

David Vereide, one of Thomsons associates at MIR, said the cells are able to self-renew through the regulation of a small quantity of genes.

"Normally, these cells are ephemeral and get used up while differentiating into specific cell types, but we found a way to interrupt that, Vereide explained in the release.

He also said their findings bring researchers very close to finalizing medical uses for stem cells.

Thomson said in the release he and his team have ambitions to progress from examining mouse cells to working with human cells, and motivate other experts to uncover even more valuable information on the topic.

"I'm hoping that other scientists who see this get inspired," Vereide said in the release. "If you dig into the progenitor state of any tissue, you will probably find core factors that will drive the expansion of those progenitors in a dish.

The new discovery will be recorded in the Dec. 9 publication of Stem Cell Reports.

Read more:
UW-Madison researchers discover method to encourage self-renewal of stem cells