Japan team develops effective method to create iPS cells from blood

KYOTO –

A Japanese research team has produced induced pluripotent stem, or iPS, cells safely and efficiently by adding artificially synthesized ribonucleic acid to human blood cells.

The team, comprising researchers from Kyoto University’s Center for iPS Cell Research and Application, or CiRA, and other institutions, also succeeded in converting the produced iPS cells into corneal epithelial cells.

Its achievements were published in a British scientific journal.

Researchers create iPS cells by introducing a specific group of genes into skin, blood or other somatic cells and reprogramming them into an undifferentiated state similar to a fertilized egg.

Utilizing synthetic RNA for gene introduction is safer than using viruses as RNA is easily decomposed and does not remain in the body for long, according to the team.

While a method to create iPS cells using skin cells and synthetic RNA has already been developed, it had been thought to be difficult to produce iPS cells from blood cells, which are easy to collect but have low reprogramming efficiency.

The research group assumed that the reprogramming efficiency of blood cells is reduced due to the overactivation of a tumor suppressor gene. It then identified a protein that inhibits the gene’s activity and incorporated it into synthetic RNA, resulting in an increase of more than 10-fold in the efficiency of reprogramming peripheral blood mononuclear cells, a type of white blood cell.

“If iPS cells can be produced safely and efficiently, the use of the technology in regenerative medicine is expected to spread rapidly around the world,” said Masato Nakagawa, a lecturer at CiRA and member of the research team.