Retinal pigment epithelial cells made from stem cells
/ CC BY-NC-SA 2.0

An important milestone in the field of regenerative biology has been reached: earlier this month a Japanese patient became the first person to receive a tissue transplant derived from her own induced pluripotent stem cells (iPS cells). The team of doctors and researchers responsible for the breakthrough took some of the patient’s own skin cells and, through a process termed reprogramming, turned them into pluripotent stem cells, a cell type that can be coaxed into becoming many different cell types in the body – this all taking place in a dish. They then exposed the iPS cells to a specific suite of molecules to direct them into becoming retinal pigment epithelial cells, a cell type found in the eye. Since the patient was suffering from age-related macular degeneration, a common eye disease that can lead to blindness, the hope was to stop the disease progression by delivering more functional retinal cells to the patient.

While human embryonic stem cells have been used for previous transplants in human patients, this is the first instance of a patient’s own cells being used for therapy. The use of patient-derived iPS cells overcomes both a therapeutic barrier (a patient can have an immune response and reject transplanted tissue if it is derived from another person) and an ethical barrier (due to contention over the use of stem cells derived from human embryos). Prior to this trial, the team had already shown that this transplantation could be done in both mice and monkeys and that the tissue could survive for at least several months with no initial side effects, giving hope that in humans the results will be the same.

Perhaps the most profound part of this accomplishment is the fact that the treatment is being tested only seven years following the first report of human iPS cells from Shinya Yamanaka’s group (whose work led to a Nobel Prize). This very short period of time reflects how rapidly the fields of regenerative medicine is moving and the amount of potential stem cell biology holds in treating a wide range of diseases. Still, even though the patient received the cells without issue and experienced no obvious immediate side effects from the treatment, it will be important to monitor her health and eyesight over the coming years to determine how safe and effective the treatment is. The outcome of this procedure will surely impact how future clinical trials using iPS cells are designed and will shape how the public views stem cell therapy as a means to combat debilitating diseases.

Acknowledgements: Thanks to Jeffrey Davis, a graduate student in the BBS program at Harvard, for providing expert insight and opinion on the topic.

Managing Editor: Tyler R. Huycke

Additional Reading: 

SITN Flash article on stem cells:

Nature news stories on iPS cell clinical trials: and

Stem cell blog post on the event:

2 thoughts on “A Stem Cell Milestone

  1. Stem cell therapies are safe and effective treatment and have saved individuals from joint replacement surgeries and research on regenerative medicine is achieve new milestones with time.

  2. The results of this method will undoubtedly influence the design of future iPS cell clinical trials, as well as the public’s perception of stem cell therapy as a treatment for debilitating disorders. Thank you for sharing!

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