I think they should call it “Hope on the Hill”. Or at least that’s how the Buck Institute for Research on Aging appeared to me as my colleagues and I drove up the winding Marin County hillside toward the institute’s campus. We visited the Buck to film the second installment of our Ask the Expert video series with associate professor Dr. Xianmin Zeng who is developing stem cell-based treatments for Parkinson’s disease. Dr. Zeng’s CIRM Early Translation II research grant is one of the furthest along the path toward clinical trials for Parkinson’s disease, giving hope to the many who suffer with the disease. (You can see all CIRM Parkinson's disease awards here.)
Along with our video equipment, we brought the questions you submitted about Parkinson's disease and stem cell research via this blog, Facebook, and Twitter. Amy Adams, CIRM’s communication’s manager, began the interview by asking for a quick description of Parkinson’s. Dr. Zeng summed it up this way:
Parkinson's disease is a neurodegenerative disorder, which leads to progressive deterioration of motor function, and the cause is the loss of dopamine-producing nerve cells…The primary symptoms for Parkinson's disease are tremor, slowness in movement, impaired balance, and stiffness. The secondary symptoms are anxiety, depression, and dementia.There is no cure for Parkinson’s. And although drugs can help reduce symptoms, they eventually lose their effectiveness. Zeng also pointed out some startling statistics about the disease’s affect on the general population, in particular the workforce:
There are about one million Americans that suffer the disease, and with the aging population now, the number is expected to increase, and about 40% of the people affected by Parkinson's disease are under the age of 60. So there is a clear impact on society in terms of losing productivity.Ten years ago, Zeng was a researcher in one of the first labs in the world to work with embryonic stem cells. Through that early work she developed methods for transforming those stem cells into dopamine-producing nerve cells, the same cells that are lost in Parkinson’s disease. Now with her own lab at the Buck, Zeng described her latest progress:
At this moment, we have decided on an embryonic stem cell line which we know can be used for clinical purposes, and we have generated two lots of dopaminergic neurons suitable for direct transplantation into the brain to hope those cells will replace the lost cells and function in the brain. So we are now in a position to go to the FDA to file for a phase 1 clinical trial in the next two years, that's my estimation, so, in hoping that we would be able to run a clinical trial in the next three to five years.In addition to using embryonic stem cells as a cell source, Zeng has also generated dopamine-producing nerve cells by using reprogrammed adult cells, such as skin cells. These so-called induced pluripotent stem cells (iPSC) are cells that have been altered to have the properties of an embryonic stem cell so that under the right conditions, they can develop into any type of tissue. When asked why she works with iPSC as well embryonic stem cells, Zeng explained that:
Because iPS cells provide an additional cell source of producing the right type of dopaminergic neurons, also because you now have a cell source coming from both normal and patient subjects, and you can use the cells to test different drugs to be a better predictor of the potential clinical benefit.Related to the question above, a person who wrote in asked, "What types of stem cells are best suited for treating Parkinson's disease?" Zeng’s answer brings up an important point that applies to the stem cell research field as a whole:
I think this is a question nobody can now provide an answer, and that's why people need to work with different types of the stem cells in order to find out exactly this question: What type of the stem cells is the best? So that's why I'm working on both ES cells and iPS cells.We really enjoyed our visit with Dr. Zeng and we hope you all learned something new from this Ask the Expert video. I know we did. And as we drove down the hill, I looked back up and marveled not only at the Buck Institute’s architecture but also at the hope contained inside it for people living with Parkinson’s and their caregivers.
You can watch the previous Ask the Expert interview with Dr. Lawrence Goldstein talking about therapies for Alzheimer's disease here.
(Note: With this video, we’re excited to launch closed-captioning for the hearing impaired as well as foreign subtitles. Click the “cc” button in the video player to change the language or general settings).