Bioethics Home >> Cloning and Stem Cells Resources | Contacts

BEST EXAMPLES OF THE CAPABILITIES OF ADULT STEM CELLS

Adult Stem Cells Repair Heart Damage

Researchers at NIH and New York Medical College-Valhalla used mice to show that injecting adult bone marrow stem cells into damaged hearts could rebuild heart tissue and help restore heart function. Newly formed heart tissue occupied over two-thirds of the damaged portion of the heart nine days after the transplant. In other experiments, significant repair of heart damage was achieved by simply stimulating the production and release of stem cells from bone marrow, with the cells migrating to the heart and repairing damage. The studies indicate that adult stem cells can generate new heart tissue, decreasing the damage of coronary artery disease.

Reference

D Orlic et al., "Bone marrow cells regenerate infarcted myocardium," Nature 410, 701-705; April 5, 2001

Companion reference mentioned but not included D Orlic et al., "Mobilized bone marrow cells repair the infarcted heart, improving function and survival," Proceedings of the National Academy of Sciences USA 98, 10344-10349, August 28, 2001

Adult Stem Cells Can Be Cultured Extensively and Still Form Multiple Tissues

Researchers at the University of Minnesota have shown that human adult bone marrow stem cells can be grown in culture for extended periods of time and still retain the ability to differentiate into multiple cell types. Even after extensive time in culture, the cells did not age but rather maintained their ability to grow, as well as their "plasticity", i.e., their ability to form different specialized cell types, including bone, cartilage, muscle, and other tissues. The results provide further evidence that sufficient numbers of adult stem cells can be generated for clinical treatments.

Reference

M. Reyes et al., "Purification and ex vivo expansion of postnatal human marrow mesodermal progenitor cells," Blood 98, 2615-2625; Nov. 1, 2001.

Adult Stem Cells Can Form Potentially All Tissues

Injection of a single adult bone marrow stem cell can reform the entire bone marrow of a mouse, forming functional marrow and blood cells and saving the life of the mouse. The transplanted bone marrow also could form functional cells of liver, lung, gastrointestinal tract (esophagus, stomach, intestine, colon), and skin, as well as cells in heart and skeletal muscle. The experiments also provided evidence that adult stem cells "home in" to sites of tissue damage.

Reference

D.S. Krause et al.; "Multi-Organ, Multi-Lineage Engraftment by a Single Bone Marrow-Derived Stem Cell"; Cell 105, 369-377; May 4, 2001.

Stem Cells From Skin Can Develop into Brain Cells and Other Tissues

A research team in Montreal, Canada have taken stem cells from the skin of mice and transformed them into brain cells and other tissues. The results point to the potential for creating a "vast and accessible supply" of neurons from an easily isolated source. The researchers' work also indicates that similarly versatile adult stem cells are found in human scalp.

Ronald Worton, head of Canada's Stem Cell Network, was quoted in news reports: "Two years ago, I would have said this is a big surprise and I wouldn't have believed it unless it could be widely reproduced. But then the dogma used to be that if you were a stem cell in [adult] bone marrow, you could only make blood cells, or if you were a stem cell in skin, you could only make skin. There's now enough lab work to say the dogma was wrong."

Reference

J.G. Toma et al., "Isolation of multipotent adult stem cells from the dermis of mammalian skin," Nature Cell Biology 3, 778-784; Sept. 2001

Companion news story for Worton quote Carolyn Abraham, "McGill team harvests stem cells from skin," The Globe and Mail, Aug. 13, 2001.

Functional Brain Cells Generated From Adult Bone Marrow Stem Cells

Scientists in Tennessee and Germany have shown that adult bone marrow stem cells in mice can generate specific functional brain cells. The marked bone marrow stem cells could be tracked in their integration into the brain and formation of fully-developed specific neurons called Purkinje [purr-kin'-jee] cells, which help with coordination. The report presents "compelling ... evidence for the generation and integration of highly differentiated bone marrow-derived neurons."

Reference

J. Priller et al., "Neogenesis of cerebellar Purkinje neurons from gene-marked bone marrow cells in vivo," Journal of Cell Biology 155, 733-738; Nov 26, 2001.

Stimulating Adult Brain Stem Cells To Treat Parkinson's Disease

Injection of a growth protein into the brains of Parkinson's rats caused their neural stem cells to grow, migrate to the site of damage, and begin to replace missing nerve cells. Eighty percent (80%) of treated rats showed decreased symptoms, with no tumor formation.

Reference

J. Fallon et al., "In vivo induction of massive proliferation, directed migration, and differentiation of neural cells in the adult mammalian brain," Proceedings of the National Academy of Sciences USA 97, 14686-14691; December 19, 2000

Adult Stem Cells Can Promote Recovery From Spinal Cord Injury

Researchers have demonstrated that adult stem cells are capable of promoting functional recovery, nerve re-growth and reconnection in rats with spinal cord injury. The animals showed limb movement and supported their body weight. Adult stem cell transplants promoted recovery even when the spinal cord was completely severed, and treated rats showed "dramatic functional improvement and anatomical repair."

Reference

A. Ramón-Cueto et al., "Functional recovery of paraplegic rats and motor axon regeneration in their spinal cords by olfactory ensheathing glia," Neuron 25, 425-435; February 2000.

Human Blood Contains Stem Cells That Can Form Multiple Tissues

Scientists at the University of Texas MD Anderson Cancer Center have found that human adult stem cells from circulating blood can form many different tissues of the body. In patients who had received transplants of blood stem cells, the donor cells not only formed new blood cells but also cells of the liver, skin, and gastrointestinal tract.

Reference

M. Körbling et al., "Hepatocytes and epithelial cells of donor origin in recipients of peripheral-blood stem cells," New England Journal of Medicine 346, 738-746; March 7, 2002