Editor’s note. The following trio of items by Dr. David Prentice appeared on his fine blog at frcblog.com
An Israeli company is conducting a clinical trial using a patient’s own adult stem cells to treat ALS (Lou Gehrig’s disease.) The method was developed by professors at Tel Aviv University.
Prof. Daniel Offen, one of the developers of the technique, says he and his team bypassed the ethical and safety issues inherent in embryonic stem cells by using adult stem cells derived from a patient’s own bone marrow. In addition, he notes that because the original cells are drawn from the patients themselves, the body should have no adverse reactions.
ALS is characterized by the progressive degeneration of motor neurons,
Cells are taken from a patient’s own bone marrow and differentiated in the lab into astrocytes, cells responsible for nurturing neurons in the brain and preventing deterioration. By releasing neurotrophic factors (which are proteins that can protect brain cells), the former bone marrow adult stem cells can protect and preserve brain cell function.
The clinical trial has been started at Jerusalem’s Hadassah Medical Center, but could be expanding soon to Massachusetts General Hospital in collaboration with the University of Massachusetts Medical School.
Scientists have reversed the aging process for human adult stem cells. Researchers at the Buck Institute for Research on Aging and the Georgia Institute of Technology have shown in laboratory studies that they can turn back the clock on the aging of adult stem cells, which are responsible for maintenance and repair of old and damaged tissues in the body. Adult stem cells are also the gold standard for patient treatments, now being used for dozens of diseases in thousands of patients around the globe.
The modern “stem cell hypothesis of aging” suggests that living organisms are as old as their adult stem cells, which explains the decline in regenerative power of our tissues as we age. Most cells show aging by the shortening of DNA sequences (called telomeres) on the ends of chromosomes. As a cell ages, the telomeres get shorter, similar to a fuse burning down.
But adult stem cells tend to maintain these fuses, so the researchers hypothesized that these repair stem cells must age by a different mechanism. They found that as we and our adult stem cells age, 65% of the DNA damage in self-renewing adult stem cells occurred within small sections of DNA called “transposable elements” or “retrotransposons”. Co-author King Jordan said:
“Retrotransposons were previously thought to be non-functional and were even labeled as ‘junk DNA’, but accumulating evidence indicates these elements play an important role in genome regulation.”
Young adult stem cells were able to suppress the activity of these genetic elements and deal with DNA damage, but older adult stem cells were less able to suppress them. Senior author Victoria Lunyak said:
“By suppressing the accumulation of toxic transcripts from retrotransposons, we were able to reverse the process of human adult stem cell aging in culture.”
Next steps will include validating the rejuvenation of adult stem cells in lab animals. The study is published in the journal Cell Cycle.
Stanford University is reporting that it has injected the fourth patient with embryonic stem cell-derived cells, the latest of a series of experiment on patients with a specific type of spinal cord injury. The trial is being run by Geron Corp. of Menlo Park, California which developed and manufactures the embryonic cells being tested.
Geron had previously announced the first and second patients, but not the third patient who was apparently injected in the last couple of months in Atlanta.
Up to ten patients may be tested in the initial experiments. Patients will be monitored for 15 years because of the significant risk of tumor development. Scientists are still trying to overcome the cancerous potential of embryonic stem cells.
Adult stem cells have already successfully improved dozens of spinal cord injury patients, documented by peer-reviewed publications, and all without concerns for tumors, transplant rejection, or harm or destruction of the stem cell donor.