Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.
Blood platelets from donors are often in short supply. Being able to mass-produce them from stem cells could be a boon for cancer patients when chemotherapy has knocked out their platelets.
Newly found stem cell primed to create blood platelets. Low blood platelet counts and the bleeding hazard it causes can be a major side effect of much cancer chemotherapy. Being able to coax the stem cells in your bone marrow into producing more platelets on demand could be a significant boon to cancer patients. Up until now researchers generally thought all the various blood components came from the same stem cells, but a British team has found a subset of those stem cells in mice that is particularly primed to create platelets. The work was published in Nature and was discussed in the Health Canal web site. Next they need to see if they can find the same stem cells in humans.
Overview of stem cell clinical trials for stroke. A writer for NextBigFuture.com reviewed the results of the 20 clinical trials using stem cells as stroke therapy that have been published in the scientific literature in the past two years. He noted that nearly all the trials were small and largely designed to test safety, but a few showed some suggestion of clinical benefit. The teams consistently reported no problems with safety.
The author also reviewed the preclinical animal experiments that supported the trials and suggests that this work is starting to point to which type of stem cell may be best for various therapeutic goals. Deciding which type of stem cell to use in various patients is something our researchers grapple with constantly. You can read about a CIRM Disease Team that is working toward a stroke clinical trial using cells derived from embryonic stem cells here.
Defining the role of the heart’s own stem cells. Researchers tend to agree that the heart has cardiac-specific stem cells, but fewer than most other tissues in the body. Because they are so scarce, no one has been sure of how much of a role they can have in repairing the heart after a heart attack. A British team developed a method to remove the heart stem cells from a strain of mice that had been shown to have the capacity to repair its damaged heart tissue. When the stem cells were removed, the animals were no longer able to make repairs.
But perhaps most important, when the stem cells were re-injected intravenously, they naturally homed to the heart and made the repair. This suggests that if heart stem cells can be mass-produced in the lab, they could be transplanted without invasive surgery. The research appeared in the journal Cell and was described in MedicalXpress.
A better method to prevent cell transplant rejection. A CIRM-funded team at Stanford used a combination of two agents not previously used to block the immune system of mice from rejecting tissues grown from embryonic stem cells. Even with chronic administration of standard immune suppressants researchers have a hard time getting transplanted cells to engraft where they are needed and stay there without being destroyed. The Stanford team administered the new combo for only a short course and still got much improved engraftment and cell survival. The work was published in the journal Stem Cells and the press release from the journal was picked up by benzinga.
They tested the new regimen with two types of tissue including heart cells and showed that not only did the cells stick around, they also repaired heart damage. The leader of the research team, Joseph Wu, also directs a CIRM Disease Team working toward a clinical trial with embryonic stem cell derived cells for severe heart failure. You can read about that project and other CIRM-funded work in heart disease here.