There are tremendous parallels between the early days of recombinant DNA technology in the 70s and the early days of stem cell research. Both created a big social uproar over whether we should be doing the work, followed by a compromise and then getting on with the research. Recombinant DNA essentially gave us unlimited access to all the genes in the body — and pluripotent stem cells provides the same thing, except for cells. For the first time, pluripotent stem cells give biomedical science access to all of the cellular building blocks of the human body.
Today, our lab is focusing on two topics: blood vessels and developmental clocks.
On the question of clocks, we’d like to understand what controls the wide variation in gestation rates across species — or why it takes 9 months for a human to develop and three weeks for a mouse. This is important because, unfortunately, human stem cells repeat this timing in a culture dish. Growing some types of cells, like neural cells, takes several months, thus making stem cell therapies difficult. If we can find a way to control developmental timing, we can make those cells available faster to treat disease.
We also decided to focus on blood vessels, from arteries to small capillaries, because any advanced engineered tissue will require a blood supply, and cardiovascular disease is a major cause of death worldwide. In the U.S. for example, heart disease and stroke are the No. 1 and No. 3 killers, respectively. Blood vessels also play a role in the pathogenesis of a wide range of other important diseases, from how cancer spreads to complications from diabetes. A better understanding of the vasculature will have an impact on the majority of conditions that kill us.
We are already seeing clinical trials based on stem cell therapies, including trials for macular degeneration, a leading cause of blindness. And multiple groups are gearing up for clinical trials for Parkinson’s disease. However, it’s the insights we will get from stem cells on how the human body works that will ultimately change the face of medicine.
Parkinson’s is a good example. This is the first time we can grow the neurons responsible for Parkinson’s in bulk and study them and understand why they die. While I am hopeful that stem cell-based transplantation therapies will work for Parkinson’s, in the long term it will be much more important to understand why those cells are dying, so we can prevent their death from occurring in the first place, eliminating the need for cell transplantation.