US institute develops new stem cell generation technique

5th December 2012 (Last Updated December 5th, 2012 18:30)

The Salk Institute for Biological Studies in the US has developed a new laboratory-based method for increased production of mature cell-derived stem cells, which are used for regenerative medicine therapies.

Salk

The Salk Institute for Biological Studies in the US has developed a new laboratory-based method for increased production of mature cell-derived stem cells, which are used for regenerative medicine therapies.

The new technique not only enables unlimited stem cell and derivative production, but significantly reduces production time from around two months to 15 days.

Salk Institute postdoctoral researcher and one of the first authors of the paper, Ignacio Sancho-Martinez, said; "One of the barriers that needs to be overcome before stem cell therapies can be widely adopted is the difficulty of producing enough cells quickly enough for acute clinical application."

Stem cells that are pluripotent are derived either directly from young cells yet to be pluripotent, or from mature cells reprogrammed to be pluripotent.

Embryonic stem cells derived from blastocysts are associated with ethical controversies and may trigger immune reactions when transplanted into patients.

Induced pluripotent stem cells (iPSCs) are a type of pluripotent stem cell artificially derived from a non-pluripotent cell, typically an adult somatic cell, by inducing a forced expression of specific genes.

iPSCs have a long laboratory production time as the somatic cells must first be reprogrammed to iPSCs and then be differentiated into a specific cell lineage before therapeutic application.

"The new technique not only enables unlimited stem cell and derivative production, but significantly reduces production time from around two months to 15 days."

iPSCs can even occasionally develop tumours, known as teratomas.

A technique of direct lineage conversion eliminates the potential problems associated with iPSCs, which includes conversion of one somatic cell into just one other cell type.

The Salk team modified the direct lineage conversion technique and developed indirect lineage conversion (ILC), where somatic cells are pushed back to an earlier state suitable for further specification into progenitor cells.

ILC can produce multiple lineages once cells are introduced to the specially developed chemical environment.

The ILC technique saves time while reducing the risk of teratomas by avoiding iPSC generation.

Salk scientists used the ILC technique to reprogramme human fibroblasts (skin cells) to angioblast-like cells, the progenitors of vascular cells.


Image: Endothelial cells derived by indirect lineage conversion from human fibroblasts (skin cells). Cell nuclei are in blue, proteins that are hallmarks of endothelial cells are green and red. Photo: Courtesy of the Salk Institute for Biological Studies.