Despite increasing efforts by both sides of the debate to sway the country’s sentiments regarding stem cell research over the past few years, the average American remains largely unaware of the science underlying the rhetoric. As the issue became increasingly politicized, the science attached to the label lost its place in public discourse. The political façade, created as a result of the debate gripping the country over the scientific use of human embryonic stem cells, was pulled down last week.
Dr. Hynek Wichterle, assistant professor of pathology at Columbia University, introduced students to one of the many frontiers of research disclosed by the advent of stem cells.
In a lecture entitled, “Use of Embryonic Stem Cells as a Tool to Study Spinal Cord Development,” Wichterle talked specifically about his work at Columbia. While some members of the scientific community are engaged in a race to find the next big cure, Wichterle has his eye on solving a part of the mystery that is the human nervous system.
“[Our team] uses stem cell technologies in combination with mouse genetics to study how neurons differ from one another,” Wichterle said.
The central nervous system, encompassing the brain and spinal cord, consists of a variety of neuronal cell types. Current understanding of these cells remains limited. It is known that unique cell types follow different developmental courses. This is where embryonic stem cells show the potential for enhancing our understanding of the vertebrate nervous system.
Embryonic stem cells are primitive cells that can develop into virtually any kind of specialized cell in the human body. These cells are theoretically capable of growing into any of the 220 cell types that exist within us. They bridge the gulf between the fertilized egg that is our origin and the architecture we become. Witcherle is using differentiating ability of stem cells to study various neuronal cell types.
“We have developed a robust protocol for the differentiation of mouse [embryonic stem] cells into spinal motor neurons and [intermediate neurons] and are developing similar methods for the generation of brain neurons,” Wichterle said.
As Wichterle focuses on unraveling the workings of the spinal cord, stems cells are currently being used to treat injuries to this vital structure.
About a year ago, the Korean Times reported that a team of scientists in South Korea was able to transplant multi-potent stem cells from umbilical cord blood into a 37-year-old female patient suffering from a spinal cord injury. Three weeks later she was able to walk on her own.
The woman’s lower limbs had been paralyzed nearly two decades ago and the injection of isolated stem cells from umbilical cord blood into the damaged part of the spinal cord was able to revive the patient’s sensory and motor neurons.
This Korean experiment could very well break the impasse that has prevented America’s own research in this arena to proceed as vigorously as possible. The stem cells used in this experiment were derived from the umbilical cord blood rather than the human embryo. Cord blood stem cells are found to be at a more advanced stage of differentiation than embryonic stem cells. They are developed enough not to provide the risk of tumor cells that comes with embryonic stem cells, while retaining the same powerful ability to differentiate into different kinds of cells.
Currently, this is the only example of a successful medical application of stem cell technology. It does suggest the possibilities that may present themselves with continued research in the field.
Experts caution that more work is needed to determine the risks involved. Immune response to foreign cells could cause complications, and the long term viability of these cells is unknown. Still, this area of research could lead to cures for spinal cord injuries and diseases like Parkinson’s.
As the political and ethical debate over human embryonic cell use rages, scientists like Wichterle are using cells collected from other animals in an attempt to solve basic scientific and medical questions.
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