Skin cells halt blindness
using iPS cell technology to stop vision degeneration in humans.
A team of scientists led by ophthalmologist Dr. Masayo Takahashi of Riken Center for Developmental Biology (CDB), Kobe, reports the world's first iPS cell-based therapy. Skin cells from a patient going blind were reprogrammed into eye cells using iPS cell technology and then transplanted back to the patient, stabilizing her vision. CiRA contributed to this work in evaluating cells prior to transplantation.
The patient suffers from age-related macular degeneration (AMD), a disease that leads to the progressive degeneration of vision due to an impairment of retinal pigment epithelial (RPE) cells. While some patients can be treated with drugs, surgical intervention that transplants retinal cells might be a better option for others.
The researchers took a skin biopsy from the patient and reprogrammed the cells into iPS cells. The iPS cells were then differentiated into RPE cells, which were prepared for transplantation.
However, the creation of iPS cells requires manipulating the DNA of the skin cells, which sometimes can cause mutations associated with cancer. Therefore, the cells used for the transplantation had to undergo exhaustive evaluation to confirm they were safe.
Because this was the first iPS cell-based therapy, CiRA was extra vigilant in checking the safety of the cells, said Assistant Professor Akira Watanabe and Professor Shinya Yamanaka, who performed genomic analyses of cells at CiRA.
CiRA looked for abnormal changes in the chromosomes, DNA copy numbers and other irregularities in the DNA, according to Watanabe. "Because these were the first ever human transplantation experiments, we made our stringency very high," Yamanaka added.
iPS cell-derived RPE cells that passed CiRA's tests were transplanted into one of the patient's eyes in order to compare the therapy with the untreated eye. One year after the surgery, the patient's vision in the treated eye had stabilized and even showed improvement.
AMD was selected as the first disease for iPS cell-based therapy, because the eye is relatively easy to diagnose post-surgery and because the number of cells needed for the transplant was relatively few compared to that needed for larger organs.
This therapy is the beginning of what Yamanaka envisions as the future for iPS cells. A major program at CiRA is the preparation of clinical-grade iPSCs that can be used by clinicians like Takahashi to treat patients. "This is a brilliant work by Dr. Masayo Takahashi. We are working with her and other clinicians and scientists to treat a wide range of diseases. AMD is the important proof of concept," Yamanaka said.
- Journal: New England Journal of Medicine
- Title: Autologous induced stem cell-derived retinal cells for macular degeneration
- Abbreviated Authors: Michiko Mandai1,2, Akira Watanabe3, ..., Shinya Yamanaka3, and Masayo Takahashi1,2
- Author Affiliations:
- Institute for Biomedical Research and Innovation Hospital, Kobe, Japan
- Riken Center for Developmental Biology, Kobe, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan