Every day it seems as if there are new information—and new controversies— being reported about stem cells. What many people do not know is that there are actually two types of stem cells: embryonic stem cells and adult stem cells. Both may have applications in diabetes research as well as many other diseases.
Embryonic Stem Cells
Embryonic stem cells (ES cells, or fetal stemcells) are taken from fertilized human eggsat a very early stage. They have two keyqualities: They can divide indefinitely, andthey can form into a variety of cell types (aprocess called differentiation). For example,ES cells might differentiate into brain cells,blood cells, pancreatic cells or other celltypes. In the diabetes field, one highlycontested study claimed that ES cells couldbe coaxed into forming insulin-secreting betacells, but several other studies dispute thesefindings.
Though we hear so much about embryonicstem cells in the news, ES cell research isliterally in its infancy. There is still much basicresearch to be done on embryonic stem cells.One holdup is the difficulty of producingstable cell lines in the laboratory (“inculture”). While ES cells can be turned intohealthy cell types in culture, they also canturn into highly undesirable cells, includingtumor cells.
There are no federal restrictions on the useof mouse embryonic stem cells, so work withES cells from mice is progressing both in theUnited States and worldwide.
Adult Stem Cells
The term “adult stem cell” is somewhatmisleading. Adult stem cells can be found inpeople of any age—infants, adolescents oradults. What makes these cells “adult stemcells” is that they are undifferentiated cells(cells with the ability to mature into anyof a variety of cell types) that come fromdifferentiated tissue (tissue that is specialized,such as brain tissue or heart tissue).
For example, adult stem cells found in thebone marrow or blood (called hematopoieticadult stem cells) can become red blood cellsor any of several types of white blood cells.There are at least 11 known tissues in humanscontaining adult stem cells.
Research with adult stem cells is furtheradvanced than the research with ES cells.Adult stem cells are currently being used fortherapies in the areas of Parkinson’s research,heart tissue regeneration, spinal cord injury,tissue regrowth, restoring blood flow,regrowing corneas, curing sickle-cell anemiaand treating multiple sclerosis and lupus.
Adult stem cells are inherently more stablethan ES cells, but they, too, present hurdlesthat researchers must overcome. Adult stemcells can neither form whole organisms, norcan they form all types of tissues and cells.
The application of adult stem cell researchis underway in animal models of type 1diabetes. At least seven published studiesover the past eight years have found differenttypes of adult islet stem cells in animals orhumans.
In terms of islet regeneration, research is mostadvanced with hematopoietic stem cells frombone marrow, which may directly benefitislet regeneration. However, the possibilityof turning adult hematopoietic stem cellsinto islet cells has drawbacks. This stemcell population may not be robust enough,meaning that of the harvested cells, only aninsufficiently small amount will mature intoislets. Other adult stem cells also located inthe bone marrow may have the potential toform into islet cells, but again, researchersare not sure if it is possible to harvest enoughof these cells to produce sufficient insulin tochange the course of disease in diabetes.
How Can I Help?
The cost of the first threeyears of clinical trials atMassachusetts General Hospitalis estimated at $11 million. Contribute to the Join Lee Nowcampaign and support theseefforts to cure type 1 diabetesin humans. Donations may be made overthe Internet or by mail.
Internet: To make a donationover the Internet, please visitwww.JoinLeeNow.org.
U.S. mail: To mail yourdonation, please make checkspayable to “Iacocca Foundation.”Please write “JoinLeeNow” inthe subject line. All donationscan be sent to:
The Iacocca Foundation
17 Arlington Street
Boston, MA 02116
Volunteering: For moreinformation, go to www.JoinLeeNow.org or contact Danielle Briscoe at (212) 255-5340, firstname.lastname@example.org.