We previously blogged about the new award grant to Dr. Amy Paller at Northwestern University, for her siRNA gold nanoparticle research, and about the work of Dr. Heiko Traupe at University Hospital in Muenster, Germany on building a better mouse for ichthyosis research.
The other two research projects discussed in the FIRST newsletter aren’t as attention-grabbing, but Dr. Roop’s research is also quite exciting once you dig into it a little bit.
The first update on the back page is from Dr. Dennis Roop, a dermatologist at the University of Colorado. (Dr. Roop was the honoree at FIRST’s 2012 testimonial dinner held in Denver Colorado, which raised over $121,000 for FIRST.) Jennifer and I attended that event, and we were very impressed with how Dr. Roop’s colleagues talked about Dr. Roop not only as a leader and a great researcher, but also as someone who never lost sight of the fact that the research in his lab helped individual patients. (We were also amused to hear about his ongoing quest to exterminate vermin in his yard. Oh, and the costumes. We’re going to remember those for a while.)
Dr. Roop previously received funding from FIRST in 2006 and 2007, in which he and Dr. Jiang Chen (also at the University of Colorado) developed a genetically engineered mouse which showed areas of epidermolytic ichthyosis (formerly known as epidermolytic hyperkeratosis, or EHK) on the mouse’s skin and paws. In September 2007, Drs. Roop and Chen reported that they had worked out a way to deliver siRNA to the mouse’s affected skin; their earlier delivery method used a modified virus, by inserting a chunk of corrected siRNA into the virus. The virus then transported the siRNA in the affected cells. In 2007, DRs. Roop and Chen were also writing about an alternative system which “may allow siRNA to be delivered topically” using nanotechnology. (Hey, that sounds familiar!)
Dr. Roop and Dr. Chen’s current research project (started in 2009 / 2010) is named “Generating immortalized cell lines and iPS cells from EHK patients“, and that project received additional funding from FIRST this year and was discussed in FIRST’s September 2012 research newsletter.
When most lay people think about stem cells, I think they first think about embryonic stem cells, which are derived from an early-stage embryo. Research on human embryonic stem cells comes with ethical issues (and can be a bit of a political hot potato). But there is a different type of stem cells — adult stem cells — which doesn’t require the destruction of an embryo.
Stem cells are important because they are cells which can differentiate — that is, they can turn into different types of cells. So of course you have this happening in the earliest stages of life. But adults also have stem cells, and part of our body’s normal process involves adult stem cells “repairing” the body by turning into (very specific) types of cells. So for instance, the skin, hair, sperm and blood in our bodies are all constantly replenished by stem cells.
When talking about adult stem cells, one of the most interesting types for researchers are”pluripotent” stem cells, which are stem cells that can give rise to any other cell type. Perhaps one of the more commonly understood sources of pluripotent stem cells comes from umbilical cord blood.
Ok, that’s a lot of background. Dr. Roop’s and Dr. Chen’s research involves the creation of “induced pluripotent stem cells” (that link goes to NIH; here is a link to the Wikipedia article on iPS cells). In other words, they are taking adult cells, and then turning them into the functional equivalent of embryonic stem cells — and thus handily avoiding the ethical issues associated with embryonic stem cells.
What does this have to do with ichthyosis research? Well, the outer layer of the skin, the epidermis, is renewed by adult epidermal stem cells. Dr. Roop’s and Dr. Chen’s research involves taking a biopsy from the skin of a patient with epidermolytic ichthyosis, growing those skin cells in the lab, and then reprogramming the lab-grown cells into induced pluripotent stem cells, or “iPS cells”.
Here’s the important part disclosed in the September 2012 FIRST research newsletter: “Dr. Roop has recently been successful in correcting the defect in the K1 [KRT1] gene in one patient’s iPS cells with a technique that uses zinc finger nucleases.”
Still with me? If not, let’s rewind a bit. Epidermolytic ichthyosis is caused by a defect in the keratin 1 or keratin 10 gene. Dr. Roop has “fixed” the defect in an induced pluripotent stem cell grown from a patient who has epidermolytic ichthyosis. Specifically, he now has an iPS cell which does not have the defect in the KRT1 gene that causes the donor’s ichthyosis. That means that the iPS cell could grow into normal, unaffected skin, because stem cells can grow into other types of cells — like all the types of cells which make up skin.
Of course, these are preliminary results, and Dr. Roop’s lab is working to see if the corrected iPS cells are genetically stable. And there’s a whole bunch of other things necessary before the iPS cells he has could be used in any therapy.
And finally, one more important thing about iPS cells. Dr. Roop points out that therapy based on iPS cells “would truly be ‘personalized medicine'”. Remember the patient who originally donated the biopsy which was “corrected” in the lab? If you graft skin grown from the “corrected” iPS cells onto that original donor, you would have a much lower risk of rejection. And that should be pretty exciting to think about.
If you have stuck with me this far, I’d really like to hear from you. I was able to unpack the summary of Dr. Roop’s research after a bit of “refresher” reading on stem cells, and a lot of the basic science is stuff I was already familiar with. I feel like Jennifer and I were able to do much the same with respect to Dr. Paller’s and Dr. Traupe’s research. Are our explanations still too complicated? Do you, our readers, need more basic background to understand what’s going on, or was all of this stuff obvious to you?
And now my confession. I’ve read the progress report from Drs. Anders Vahlquest and Hans Torma from University Hospital in Uppsala, Sweden. Their FIRST-funded project, “Studies on novel therapeutic options for epidermolytic ichthyosis affecting the skin barrier” has also received renewed funding from FIRST. I’ve read the original description and the “progress report” in the newsletter perhaps a half dozen times already, and I have to confess that I haven’t been able to decipher what’s going on. I think their research involves trying to figure out whether certain other substances might be good treatments for epidermolytic ichthyosis, and their method is breaking down EI cells and then testing the results against a large library of chemicals. But I could be really wrong on that so don’t quote me! Based on what’s publicly available right now, I’m a bit at a loss to see how the Vahlquest and Torma research fits into the “big picture”, and I’d love if someone could help me figure that out.
This post has not been approved by anyone on the FIRST staff, the MSAB or Board; all errors and misstatements in this article are ours and ours alone.
12/4/2012 update: FIRST’s latest newsletter contains some additional tidbits regarding this research, which we blogged about in the post, Ichthyosis Research: Updates from FIRST.