8. Abstracts of Interest
Uncovering How Bone Marrow Cells Can Potentially Regenerate Brain Tissue
Japanese researchers have found a piece of the "missing link" about how bone marrow cells restore lost neurologic function when transplanted into animals exhibiting central nervous system disorders, according to a study in the March issue of the Journal of Nuclear Medicine.
"Our study showed that cell transplantation therapy may improve brain receptor function in patients who suffered from cerebral stroke, improving their neurological symptoms," said Satoshi Kuroda, M.D., Ph.D., who is with the department of neurosurgery at Hokkaido University School of Medicine in Sapporo, Japan.
What researchers do know is that cells found in bone marrow may provide a safe, ethical source for replacing brain cells lost to neurological disorders such as Alzheimer's and Parkinson's diseases. Studies have shown that cells taken from human bone marrow may possibly be converted into neural cells.
Using autoradiography (a technique that uses X-ray film to visualize radioactively labeled molecules) and fluorescence immunohistochemistry (the testing of sections of tissue for specific proteins by attaching them with specific antibodies), the researchers examined the binding of a radioactive molecule with a specific receptor protein in animals with cerebral infarcts or strokes. Their findings "clearly showed" that bone marrow cells "may contribute to neural tissue regeneration by migrating toward the periinfarct area and acquiring the neuron-specific receptor function," reports the JNM article.
To see the full version of this Article look in Radiology/Nuclear Medicine News
Article Date: 19 Mar 2006
Techniques Push Stem Cells to Repair Damaged Nerves
New studies suggest that use of cells derived from bone marrow may prompt stem cells to repair nerve damage caused by stroke or spinal cord injury. Researchers at the Medical College of Georgia, Augusta, examined bone marrow-derived multi-potent progenitor cells, which have the ability to develop into different kinds of cells, including nervous system cells. Both human and rat bone marrow cells were transplanted into rats with induced strokes. Both types of cell transplants led to a reduction in motor impairments in the rats, the researchers reported. In neonatal rats, the transplanted cells migrated out from the transplant sites toward another nearby brain region. The Georgia team found no evidence of tumor formation. To view the entire article go to Health Day News dated April 7th 2006.
Researchers Have Evidence Bone Marrow Stem Cells Become Brain Cells
Using a potion of growth factors and other nutrients, scientists at Jefferson Medical College have shown in the laboratory they are able to convert human bone marrow stem cells into adult brain cells.
The results suggest such stem cells may have potential use in treating neurodegenerative diseases such as Parkinson's.
"The goal [of the work] is to find stem cells that we can differentiate into dopamine neurons to replace those lost in Parkinson's disease," says developmental biologist Lorraine Iacovitti, Ph.D., professor of neurology at Jefferson Medical College.
Human bone marrow stem cells - also known as pluripotent stem cells - normally give rise to human bone, muscle, cartilage and fat cells.
Other scientists have shown previously that at least a portion of mouse bone marrow stem cells treated with various growth factors and other agents will go on to resemble neurons in cell culture.
Dr. Iacovitti's team used the previous group's cocktail of growth factors and nutrients on human bone marrow stem cells and found that some cells converted to neurons."
By experimenting with different combinations of growth factors and nutrients, they eventually found a cocktail of reagents that converted 100 percent of cells within an hour - a stunning development that had never been shown before.
"It flew in the face of everything I knew from developmental biology," Dr. Iacovitti says. "We've identified factors that get 100 percent of human bone marrow stem cells converted to neurons very quickly." Not only do the converted cells look like neurons, she says, they contain neuronal proteins.
The converted stem cells have neuronal markers and markers that are identified with subclasses of neurons. "That's important because we've shown they can convert to specific classes of neurons".
"The major advantage of using adult human bone marrow stem cells is that each person can be his own donor, meaning they can have an autologous graft of cells without rejection," Dr. Iacovitti says.
Reported November 2007 at the annual meeting of the Society for Neuroscience in San Diego.
Bone Marrow Stromal Stem Cells: Nature, Biology, and Potential Applications
Bone marrow cells are progenitors of skeletal tissue components such as bone, cartilage and adipocytes. In addition, they may be induced to undergo unorthodox differentiation, forming neural and myogenic cells. As such, they represent an important paradigm of post-natal nonhematopoietic stem cells, and an easy source for potential therapeutic use.
Bone marrow has traditionally been seen as an organ composed of two main systems rooted in distinct lineages—the hematopoietic tissue proper and the associated supporting stroma. The evidence pointing to a putative stem cell upstream of the diverse lineages and cell phenotypes comprising the bone marrow stromal system has made marrow the only known organ in which two separate and distinct stem cells and dependent tissue systems not only coexist, but functionally cooperate. Originally examined because of their critical role in the formation of the hematopoietic microenvironment (HME), marrow cells later came to center stage with the recognition that they are the stem/progenitor cells of skeletal tissues. More recent data pointing to the unexpected differentiation potential of marrow cells into neural tissue or muscle grant them membership in the diverse family of putative somatic stem cells. These cells exist in a number of post-natal tissues that display transgermal plasticity; that is, the ability to differentiate into cell types phenotypically unrelated to the cells in their tissue of origin.
The increasing recognition of the properties of marrow cells has spawned a major switch in our perception of their nature, and ramifications of their potential therapeutic application have been envisioned and implemented. Yet, several aspects of marrow stromal cell biology remain in question and unsettled throughout this evolution both in general perspective and in detail, and have gained further appeal and interest along the way. These include the identity, nature, developmental origin and in vivo function of marrow stromal cells, and their amenability to ex vivo manipulation and in vivo use for therapy. Just as with other current members of the growing list of somatic stemcells, imagination is required to put a finger on the seemingly unlikely properties of marrow stromal cells, many of which directly confront established dogmas or premature inferences made from other more extensively studied stem cell systems. Source Stem Cells, Vol. 19, No. 3, 180-192, May 2001.