Just say “stem cell research,” and scientific, religious, ethical and political red flags immediately go up.
While the debate continues about expanding federal funding for human embryonic stem cell research, Northwestern researchers are moving forward, investigating the science and the ethics of research in both embryonic stem cells and adult stem cells. The hope is that unlocking the mysteries of these powerful cells could lead to new treatments, and possibly even cures, for devastating diseases and disorders such as Parkinson’s, cancer, heart disease, diabetes and spinal cord injury.
Stem cells are unspecialized cells that are thought to be able to reproduce themselves indefinitely and, under the right conditions, to develop into mature cells — such as a muscle cell, a brain cell or a red blood cell — with specialized functions.
With its promise to revolutionize medicine, stem cell biology has entered the mainstream of what life scientists need to think about in their research.
“The stem cell community at Northwestern is growing, and we can be proud that our science is very competitive,” says John Kessler, Ken and Ruth Davee Professor of Stem Cell Biology and chair of the department of neurology at the Feinberg School of Medicine.
The quality of research was recognized a year ago when Northwestern was one of two institutions selected by the National Institutes of Health to receive a $3.6 million grant as a Center of Excellence in Transitional Stem Cell Research. The center is part of a much larger stem cell institute at the University, which is just getting off the ground. Kessler is director of both the institute and the NIH center, which can only utilize and support work with federally approved stem cell lines.
“A large number of researchers are using various kinds of stem cells and studying many different organ systems — the nervous system, the skin, immune systems, the heart, the pancreas,” says Kessler, whose own work focuses on regenerating the spinal cord after injury and brain cells after stroke. “People now are thinking about how to apply stem cell biology to almost every organ system. Every organ is made of cells, which are ultimately derived from different populations of stem cells. If we want to repair organs that have been damaged, we have to understand stem cell biology.”
Three types of stem cells exist. The first is the totipotent stem cell, which can by itself give rise to an entire embryo. An example is a fertilized egg in the uterus. The second kind is the pluripotent stem cell. A pluripotent cell cannot by itself develop into an embryo, but it can become any one of the more than 200 cell types that make up the human body. An example is the embryonic stem cell. The third type is the multipotent stem cell. A multipotent stem cell can give rise to more than one type of cell but not all the different cells in all the organs. Commonly known as adult stem cells, multipotent stem cells can be found in almost every organ of the body, including the brain, liver, bone marrow and skin.
“Scientists are particularly excited about embryonic stem cells because of their versatility, but we are at the very beginning of our learning process,” says Mary Hendrix, Medical Research Institute Council Professor at the Feinberg School of Medicine and president and scientific director for the Children’s Memorial Research Center.
“While adult stem cells have been around for three decades — they are used in bone marrow transplants — embryonic stem cells were first reported only in 1998,” says Hendrix, who studies the ability of pluripotent stem cells to renew themselves indefinitely, which may shed light on the growth of cancer cells. “A lot needs to be learned about the best methods for isolating, maintaining and differentiating human embryonic stem cells.”
This spring Hendrix was one of three Northwestern researchers to receive stem cell research grants from the Illinois Regenerative Medicine Institute. With this support, Hendrix and colleagues will study human stem cells to determine their potential to reverse the progression of malignant tumors, muscular dystrophy, Parkinson’s disease, brain injury and epilepsy.
Other projects across the University, to name just a few, include studying stem cells for use in vascular tissue engineering and the development of replacement blood vessels; using pluripotent stem cells to generate insulin-secreting cells, which could be used to treat diabetes; learning about epidermal stem cells, which play a central role in maintaining skin and repairing wounds; and investigating how neuronal stem cells give rise to the diversity of cells in the mature brain, knowledge that may lead to therapies for neurodegenerative diseases such as Parkinson’s.
“The promise of stem cell research may also lie in its use in basic science. Understanding how brains develop may teach us a lot about what happens when brains begin to deteriorate,” says Laurie Zoloth, professor of medical humanities and bioethics and director of Feinberg’s Center for Bioethics, Science and Society, which works closely with Northwestern’s stem cell initiatives.
“Stem cell research allows us to ask very exciting questions quite broadly, even as we are careful to remember that this is a new and unknown field. It is a hope, not a promise. And the best hope for emerging science is an open quest — it is that very openness that calls for an open academic conversation across the ethical differences that may divide us.” — M.F.