Tag Archives: mesenchymal

Stem Cells Show Promise in Reducing Hardening of the Arteries

Durham, NC – The medical world is excited about the potential that stem cells have demonstrated in aiding the recovery of patients who have suffered a heart attack. Now, a new study appearing in the January issue of STEM CELLS Translational Medicine indicates that stem cells may also benefit those who suffer from hardening of the arteries.

Hardening of the arteries – or atherosclerosis – occurs due to a buildup of fats, cholesterol and other substances in and on the artery walls. The arteries become hardened by fibrous tissue and calcification and, as the plaque grows, it clogs the artery tubes, reducing the oxygen and blood supply to the affected organ. If the artery becomes severely blocked, it can cause death of the tissue fed by the artery and lead to a heart attack or stoke.

Stem Cells Show Promise in Extending Transplanted Kidneys’ Survival Time

Can stem cells provide an answer to the perplexing question of how to ensure long-term survival of transplanted kidneys? The results of a new Phase 1 clinical trial say maybe so. Details of the trial, conducted by researchers at Leiden University Medical Center, The Netherlands, are published in the current issue of STEM CELLS Translational Medicine.

Kidney transplants have long been the treatment of choice for many patients with end-stage renal disease, and the short-term results are excellent. But unfortunately, the viability of these kidneys over time has not improved accordingly, often due to fibrosis, which is a scarring of the transplanted organ generally caused by the immune system rejecting it.

The LUMC team, led by Marlies E.J. Reinders, M.D, Ph.D., and Ton J. Rabelink, M.D., Ph.D., decided to test whether stem cells might keep fibrosis in check. They focused on mesenchymal stromal cells, a type of stem cell found throughout the body, including in bone marrow.

Early Results Show Promise for Stem Cells in Treating Chronic Liver Failure

Stem cell transfusions may someday replace the need for transplants in patients who suffer from liver failure caused by hepatitis B, according to a new study coming out of Beijing. . The results are published in the October issue of STEM CELLS Translational Medicine. Worldwide more than 500,000 people die each year from this condition.

“In China, hepatitis B virus (HBV) infection accounts for the highest proportion of liver failure cases. While liver transplantation is considered the standard treatment, it has several drawbacks including a limited number of donors, long waiting lists, high cost and multiple complications. Our study shows that mesenchymal stem cell (MSCs) transfusions might be a good, safe alternative,” said Fu-Sheng Wang, Ph.D., M.D., the study’s lead author and director of the Research Center for Biological Therapy (RCBT) in Beijing.

Wang along with RCBT colleague, Drs. Ming Shi and Zheng Zhang of the Research Center for Biological Therapy, The Institute of Translational Hepatology led the group of physician-scientists from the centers and Beijing 302 Hospital who conducted the study.

MSC transfusions had already been shown to improve liver function in patients with end-stage liver diseases. This time, the researchers wanted to gauge the safety and initial efficacy of treating acute-on-chronic liver failure (ACLF) with MSCs. The American Association for the Study of Liver Diseases and the European Association for the Study of the Liver define ACLF as an “acute deterioration of pre-existing chronic liver disease usually related to a precipitating event and associated with increased mortality at three months due to multisystem organ failure.” The short-term mortality rate for this condition is more than 50 percent.

MSCs have self-renewing abilities and the potential to differentiate into various types of cells. More importantly, they can interact with immune cells and cause the immune system to adjust to the desired level.

Of the 43 patients in this pilot study — each of whom had liver failure resulting from chronic HBV infection — 24 were treated with MSCs taken from donated umbilical cords and 19 were treated with saline as the control group. All received conventional therapy as well. The liver function, adverse events and survival rates were then evaluated during the 48-week or 72-week follow-up period.

Along with increased survival rates, the patients’ liver function improved and platelet count increased. No significant side effects were observed throughout the treatment and follow-up period.

“While the results are preliminary and this pilot study includes a small number of patients, MSC transfusions appear to be safe and may serve as a novel therapeutic approach for HBV-associated ACLF patients,” Dr. Shi said.

“The study also highlights several key issues that will need to be considered in the design of future clinical studies, such as the optimal type of stem cells that will be infused, the minimum effective number of the cells and the best route of administration,” Dr. Wang added.

“These results are certainly promising and the strategy merits additional study, especially considering the shortage of donor organs”  said Anthony Atala, MD, Editor of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine.

Stem Cell Therapy for Spinal Cord Injury

Part 1 of a 5-Part Series: Dr. Neil Riordan discusses mesenchymal stem cell sources from umbilical cord Wharton’s jelly, stem cell expansion, therapeutic potential of umbilical cord mesenchymal stem cells vs. bone marrow mesenchymal stem cells, CD34+ hematopoietic stem cells from umbilical cord blood and the scientific rationale supporting stem cell treatment of spinal cord injury. View part 2 here: http://youtu.be/I17-wYIEZ84
Visit the Stem Cell Institute at www.cellmedicine.com

Stem cell therapies for hearts inching closer to wide use

By Elizabeth Landau, CNN.com

If you’ve just had your first heart attack, doctors may one day be able to reverse the damage done with stem cell therapy.

An intravenous method of injecting stem cells into patients who had experienced heart attacks within the previous 10 days suggested that this method works to repair — not just manage — heart damage, a recent study found.

The study is a step forward in a field in which a lot of approaches have been tried in animals and preliminary human trials, but none has been approved for widespread clinical use for heart patients.

The new results are a milestone in stem cell research, and for patients, said Jeffrey Karp, a researcher at Brigham and Women’s Hospital in Boston, Massachusetts, who runs a stem cell biology lab at Harvard University. He was not involved in the study.

Most current clinical approaches are focused on managing problems, not addressing the root of the damage, he said.

“Many patients who have a heart attack will go on to suffer heart failure,” he said. “It’s imperative to try and fix the root of the problem as quickly as possible.”

The research, published in the Journal of the American College of Cardiology, were part of a phase I study that set out to show safety. The trial has moved on to phase II, which is taking place in 50 hospitals in the United States, said Dr. Joshua Hare, director of the Interdisciplinary Stem Cell Institute at the University of Miami’s Miller School of Medicine and lead author of the study.

“We’re looking on the time frame here of five years, in the best-case scenario, to have approved cardiac stem cell therapies,” Hare said.

Coronary heart disease, which causes heart attacks and angina — chest pain resulting from the heart not getting enough blood — is the leading cause of death in the United States, with nearly 450,000 in 2005, according to the American Heart Association. About 1.1 million people have attacks occur in the United States each year, according to the National Heart Lung and Blood Institute.

The particular kind of cells used in this research are called mesenchymal stem cells, and come from adults, not embryos.

The researchers are using a mesenchymal stem cell therapy that is marketed by Osiris Therapeutics Inc. under the name Prochymal. The drug, which consists of stem cells from donor bone marrow, gets injected into the vein. The cells then travel through the bloodstream and take up residence in the heart.

Mesenchymal stem cells have some natural homing capability, and injury serves as a homing beacon for them, Karp said.

The stem cells reduce the amount of scar tissue and increase the pumping strength of the heart in heart attack patients, Hare said. To a limited extent, they also grow new heart muscle.

The phase I results from 53 patients are not definitive proof that the treatment is effective, but do suggest so, Hare said. In accordance with clinical trial regulations set by the Food and Drug Administration, phase I is meant to show safety, while phase II and phase III trials are done on a larger group of subjects and evaluate how well the drug works.

In this trial, patients’ doses ranged from 35 million cells to 350 million cells. There was no change or increase in side effects in treatments getting higher doses of cells, but it seemed that the treatment was more effective — at least in terms of reducing electrical problems — in the high dose group, he said.

In separate trials, researchers are looking at how the technique works in patients who have had heart attacks many month or years in the past, Hare said.

The study shows the results of a six-month follow-up with patients in 2007, and researchers are presently working with data from the two-year follow-up.

More broadly, besides bone marrow transplantations, there have not been any major successes in the stem cell field in terms of helping large numbers of patients, Karp said.

“Mesenchymal stem cells are poised to really be the next major success in cell therapy that could be used to treat tens of thousands of patients,” he said.

There are several advantages to using mesenchymal stem cells for heart therapy. First, they are adult stem cells, so there are no ethical issues that surround research on embryonic stem cells. Secondly, at least from a safety perspective, mesenchymal stem cells do not require matching — any donor can give cells to any other donor, and no immunosuppresant drugs are necessary, he said.

Still, millions of cells are required in order for enough stem cells to reach the heart and have a therapeutic benefit, and it’s costly to get the required numbers of cells for each patient, Karp said. An area of improvement would be making the stem cell treatment more efficient, he said.

“If we could increase the number of cells that could reach the heart, that would have significant advantages to this approach,” Karp said.

This method of intravenous injection means that the procedure theoretically could be performed in a doctor’s office or clinic, increasing the accesibility to patients, Karp said.

A more invasive stem cell delivery technique has been showing positive results in other clinical trials, involving injecting patients’ own stem cells directly into heart muscle.

The largest national stem cell study for heart disease, sponsored by Baxter Inc., uses this surgical method, and recently announced success in a 12-month phase II trial for patients with severe angina. Researchers found that participants had less pain and an improved ability to walk.

Because stem cells are delivered through a catheter in this method, there is a risk of perforation of about 1 percent, Dr. Douglas Losordo, cardiologist at Northwestern Memorial Hospital in Chicago, Illinois, told CNN earlier this year. The drug, GCSF, which mobilizes stem cells, also carries a small risk of blood clotting.

For the Osiris trials, further research is ongoing determine whether patients would benefit more from more infusions of the stem cells, or if it’s better for the stem cells to come from their own bodies instead of from a donor, Hare said.

While there’s less chance of a person’s body rejecting his or her own stem cells than from a donor, there is a time delay, he said. Taking bone marrow and amplifying the stem cells in it could take up to five weeks, whereas donor cells could be made readily available, he said. On the other hand, it is unclear whether a donor could potentially transmit a disease to the recipient in the process.

If you are interested in enrolling in a clinical trial, you can find one at clinicaltrials.gov.  The Orisis trial is still recruiting participants.

Hysterectomies Could Be Source of Stem Cells

Researchers eye tissues that are normally discarded after surgery

From health.usnews.com

Fallopian tubes removed from fertile women of child-bearing age during hysterectomies or other procedures might prove to be a new source of highly sought-after stem cells.

Researchers from the University of Sao Paulo in Brazil found that human fallopian tubes are rich in mesenchymal stem cells. The team isolated and grew these cells in a laboratory and differentiated them into muscle, fat, cartilage and bone cell lines without producing problems in the cell chromosomes, according to a report in the Journal of Translational Medicine.

“In addition to providing an additional potential source for regenerative medicine, these findings might contribute to reproductive science as a whole,” study leader Tatiana Jazedje, of the university’s Human Genome Research Center, said in a news release from the journal’s publisher.

Past studies have also shown success with isolating and differentiating mesenchymal stem cells harvested from umbilical cords, dental pulp and body fat.

Together, these findings are of great interest, the researchers said. “Moreover, the use of human tissue fragments that are usually discarded in surgical procedures does not pose ethical problems,” Jazedje said.