A researcher talks about the kinds of work his team and others are doing toward realizing the potential of stem cell therapies.
By Herb Drill
For such tiny and indistinct things, they sure do have a big impact on people with strong opinions. It’s easy to think they’re nothing but abstractions, but they’re real all right. You can even see them, if you have enough magnification and go to a laboratory where researchers work with them.
They’re called stem cells, and researchers are doing real work and making real progress with them, steadily unlocking their mysteries to understand their therapeutic potential.
Blank Slates
What makes them seem so unreal, perhaps, is the great promise researchers claim for them. Studying stem cells, they say, may help explain how serious conditions such as birth defects and cancer develop. If this research is fruitful, further research may unlock secrets that can lead to discoveries of cures for forms of cancer, diabetes, multiple sclerosis (MS), and a host of illnesses that seem incurable. Potentially, stem cells could make new healthy cells and tissues, replacing unhealthy ones that cause or complicate conditions including Parkinson’s, Alzheimer’s, spinal cord injury (SCI), heart disease, and arthritis.
Scientists view stem cells as “blank slates” of body cells; in infancy, they possess the potential to become many different types of cells. They can be prompted to become a particular cell or tissue type, and reproduce continually as that type on their own. These healthy cells could replace malfunctioning cells viewed as largely responsible for a disease.
The path is clear at McKnight Brain Institute at the University of Florida/Gainesville (MBI-UF), where more than 300 faculty from many academic departments and colleges do research and educational programs to cover “nearly all aspects of basic, clinical, and translational neuroscience.”
Dr. Dennis Steindler is executive director of MBI-UF. He works daily to understand the biology, growth, and potential of neural stem cells. “My major research goal is to see this therapy become a major treatment for debilitating neurological diseases,” Steindler says. Toward that end, Steindler and his researchers are at work on five different but concurrent sets of experiments that aim to “advance our understanding and use of neural stem cell therapies.”
Working with Stem Cells
Steindler explains how his team, which he co-led with Dr. Bjorn Scheffler, a UF neuroscientist (the two are involved with Regen Med Inc., a biotechnology company that seeks to use stem cell technology to develop human therapeutics), use mature human brain cells from epilepsy patients to generate new brain tissue in mice. The MBI-UF scientists “coax these pedestrian human cells” to produce “large amounts of new brain cells in culture,” with one cell “theoretically” able to begin a division cycle that “doesn’t stop until the cells number about 10 to the 16th power.”
“We get the human tissue from patients undergoing resection of brain tissue for intractable epilepsy, as well as from postmortem brain specimens,” Steindler explains. “Then, brain tissue is placed in tissue culture to isolate cells that behave like brain cell progenitors. These cells are used in transplantation studies in animal models of human diseases, including Parkinson’s and Alzheimer’s, to see if they can treat the disease.”
Through a “long and difficult process,” Steindler says, when donor cells were given a “bath of growth agents within cell cultures,” a type of cell emerged that behaved like something called a “neural progenitor.” That’s a cell that’s a “bit further along” in development than a stem cell but “shares a stem cell’s ability to divide and transform into different types of brain cells.”
Even when the epilepsy patients’ cells were transplanted into mice, “bypassing growth enhancements,” they took “cues from surroundings” and produced new neurons.
Regenerating Broken Body Parts
Armed with “state-of-the-art imaging and diagnostic technologies, plus basic science,” Dr. Steindler relates, scientists apply the “most current genetic, molecular/cellular therapeutic approaches” for SCI repair. Study and clinical efforts are “focusing on the innate, regenerative potential of spinal cord cells and circuitries” to try and “rebuild cells and pathways lost to injury and disease.”
Another success Steindler points to is with bone marrow. Adult stem cells within bone marrow have long been known to have the ability to “replace all of our blood cells,” and such transplants have “gained wide use” as therapies for diseases such as leukemia and breast cancer. “We know a region of the human brain retains potential disease-fighting cells,” Steindler says. “This ‘brain marrow’ attempts to repair the injured brain but appears to need help from scientific research to uncover ways to boost their abilities.”
The most obvious benefit of these cells, he emphasizes, is “they’re yours, and will not be attacked by your own immune system” after application of technologies to “mobilize” them for protecting or replacing lost cells in diseases like those mentioned. Stem cells from donors, including embryonic stem cells, “can’t offer this possibility without the application of ethically-controversial approaches.”
Meanwhile, retinal physicians look to therapies which might benefit patients globally who have little or no hope for better or saved vision. Stem cells have been used for ophthalmic problems such as severe corneal disease, says Gerald Helzner, senior editor of Ophthalmology Management and Retinal Physician magazines. Stem cells for retinal disease remain “investigational,” but with their “multi-potential nature” they may offer hope for “biological management” for some diseases that have rendered patients with reduced or no vision.
In particular, Steindler notes, regenerative medicine is beginning to uncover cells which are “progenitors” of all spinal cord circuits and “remain in adult neural tissues for life.” They’re “amenable” to replacing lost cells and connections via exposure to new drugs which “rekindle their natural tissue-building abilities.” These progenitors are studied at
MBI-UF, teaming with the Miami Project to Cure Paralysis, to be “seeded into (SCI) with the hope of reversing the damage and encouraging regeneration.”
With knowledge gained from studies of animals with ability to regenerate a damaged spinal cord, “like salamanders,” Steindler adds, MBI-UF’s Regeneration Project is assembling the “most gifted investigators [worldwide] … to learn how humans might be able to regenerate tissue damaged or lost from SCI.” Finally, MBI-UF neuroscientists, who cooperate with rehabilitation researchers, are “finding ways to return some lost functions following injury in incremental ways that one day may lead to new [therapies] that could globally improve the lives of [SCI] patients.”
In his wheelchair in Jacksonville, Florida, Herb Drill heads Able Me & Associates. His e-mail address is herbdrill@ableme.com. He has Muscular Dystrophy.
