I received many emails regarding our progress on Wolfram syndrome induced pluripotent stem cells (iPS cells) in the past two weeks. I would like to update you on a few things. As I mentioned in my previous blogs, we have created many iPS cells from skin cells of patients with Wolfram syndrome. These iPS cells can differentiate into various types of cells including brain cells and pancreatic beta cells that are damaged in patients with Wolfram syndrome
1. Disease modeling
We could successfully differentiate these iPS cells into neural progenitor cells. These are immature brain cells. We found that neural progenitor cells from patients are not completely damaged, which was surprising, but good news to us. Instead, they have altered calcium homeostasis. My impression right now is that cells from patients with Wolfram syndrome are "sensitive" to environmental stress, especially stimulus that changes cellular calcium levels. So we are looking for drugs that can modulate calcium homeostasis in cells to develop a treatment for Wolfram syndrome.
2. Testing drugs
As I mentioned above, we are focusing on drugs that can modulate calcium homeostasis in cells, especially endoplasmic reticulum calcium levels, to develop a treatment. Three drugs out of five candidate drugs that we have identified so far can control endoplasmic reticulum calcium levels. We are testing these three drugs using iPS cells.
3. Correcting a mutation
Using a special enzyme and artificial DNA, we are replacing an abnormal segment of Wolfram gene with a normal segment of Wolfram gene in patient-derived iPS cells. In theory, we should be able to correct altered calcium homeostasis through this process.
4. Making eye cells
A group in Columbia University Medical Center in New York could successfully make pancreatic beta cells from Wolfram syndrome iPS cells. We are collaborating with this group. So we are focusing our own efforts on making eye cells from Wolfram syndrome iPS cells. This is a collaboration project with a group in a major medical center in Japan. They have a special "recipe" for making eye cells. Because a clinical trial using this technology for an eye disease will start in a few weeks in Japan, I feel that this collaboration is so important for us. A physician and scientist who is working on this collaboration project will come to the US and work with us in a few months. The arrangement has been made, and the Japanese agency will partially support this effort.
You may be interested in a clinical study using iPS cells for an eye disease. Here is some info.
http://blogs.nature.com/news/2013/07/japan-to-start-stem-cell-study-on-humans.html
http://www.riken.jp/en/pr/press/2013/20130730_1/
