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From the Brink of Death to Jogging on the Beach
Willerson describes results to date and the promise of stem cell research
Visiting at the President’s Executive Luncheon are, from left: State Rep.
Martha Wong, UT Health Science Center at Houston President James T.
Willerson, M.D.; State Rep. Talmadge Heflin, chairman of the House
Appropriations Committee; and Chase Untermeyer, vice president for
governmental relations. Photo by Nancy Hudgins
What if physicians could take your stem cells and rebuild your heart – or ultimately your brain?
That provocative question is the basis of research that The University of Texas Health Science Center at Houston President James T. Willerson, M.D., discussed at the Nov. 5 President’s Executive Luncheon at the Warwick Hotel.
In collaboration with colleagues at the Texas Heart Institute, where he is medical director, Willerson helps lead one of the two largest clinical studies in the world to treat end-stage heart disease patients using their own bone marrow-derived stem cells at Hospital Procardico in Rio de Janeiro, Brazil. His partners in this effort are Emerson Perin, M.D., Ph.D., a native Brazilian and director of New Interventional Cardiovascular Technology at Texas Heart Institute, and Hans F. R. Dohmann, M.D., at Hospital Procardico.
Stem cells are unique in their ability to continually divide, and they have the potential to turn into virtually any cell type or tissue in the body.
“It’s become apparent in the last few years that if one injures a blood vessel or the heart, stem cells are recruited to that site of injury. They’re recruited out of your bone marrow, out of your blood and maybe from adipose (fat) tissue,” said Willerson, who also holds the Edward Randall III Chair in Internal Medicine and the Alkek/Williams Distinguished Professorship. “The stem cells come to try to repair that injury. We and others from around the world have wanted to use stem cells from a relevant site in organ repair.”
After about three or four years of study in experimental animal models, “we became convinced that we could repair much of the injury in an animal heart that was injured, and sometimes in a blood vessel, using stem cells,” Willerson said.
The research team began a clinical study in Rio de Janeiro, Brazil. All of these patients had prior heart attacks; many had already had angioplasties, stents and bypass surgery; and some were on waiting lists for heart transplants.
The patients have end stage heart failure: “they can’t breathe, can’t walk, can’t work and die suddenly,” Willerson said.
Using a special catheter to find those areas of the heart that are still alive, Perin injected 15 million up to many as 150 million of the patients’ own bone marrow cells directly into the heart muscle. Twenty patients have been treated so far.
“In a period of follow-up as short as four months and as long as one year, these patients have improved blood flow and improved function in the heart, both at the precise sites where we injected the cells and overall in the heart,” he said.
A recent report on the Discovery channel showed two of the treated patients jogging on the beach in Rio.
Willerson cautioned that “the numbers are not large enough and the follow-ups not long enough to claim any kind of victory. We’re trying to help people, and we would like what we’ve been working on for several years to be very useful to people.”
In addition to regenerating tissues, stem cells may be useful as vectors for genes, he said. “The patient who has premature coronary disease, the patient who develops dementia, the patient who has diabetes, the patient who has liver disease – each has a certain set of genes and proteins that are important to the normal function of the heart or the brain, the pancreas or the liver. We are back in the animal laboratory now working to deliver genes to these cells.”
Genes have been identified that:
elevate high density lipoprotein (the so-called good cholesterol) and prevent apoptosis (programmed cell death),
prevent blood clots,
prevent restenosis (narrowing of arteries that have been opened with stents).
The next step is to begin clinical trials using stem cells to deliver these genes to patients.
“I think the gene and protein discoveries in front of us, the stem cell work, the ability to regenerate organs with some of these approaches is going to revolutionize medicine,” Willerson said. “This is a very exciting time to be alive. Our children and grandchildren – and some of us – can benefit.”
Willerson acknowledged the work of key colleagues in the research: Yong-Jian Geng, M.D., Ph.D., associate professor of internal medicine at the UT Medical School at Houston and director of UT’s Center for Cardiovascular Biology and Atherosclerosis Research; S. Ward Casscells, M.D., the health science center’s vice president for biotechnology, the John Edward Tyson Distinguished Professor of Medicine and a professor of cardiology at the Medical School; L. Maximilian Buja, M.D., the health science center’s executive vice president for academic affairs, the H. Wayne Hightower Distinguished Professor in the Medical Sciences and holder of the Distinguished Chair in Pathology and Laboratory Medicine; Edward T. H. Yeh, M.D., director of the Research Center for Cardiovascular Disease at UT’s Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases and chairman of cardiology at the UT M. D. Anderson Cancer Center; and Silvio Litovsky, M.D., senior research scientist for the Vascular Cell Biology Laboratory at Texas Heart Institute.
Geng, Buja and Yeh also hold faculty appointments in the UT Graduate School of Biomedical Sciences at Houston.
— by Ina Fried, Public Affairs