Stem cell scientists had what first appeared to be an easy win for regenerative medicine when they discovered mesenchymal stem cells several decades ago. These cells, found in the bone marrow, can give rise to bone, fat, and muscle tissue, and have been used in hundreds of clinical trials for tissue repair. Unfortunately, the results of these trials have been underwhelming. One problem is that these stem cells don't stick around in the body long enough to benefit the patient.
But Harvard Stem Cell Institute (HSCI) scientists at Boston Children's Hospital aren't ready to give up. A research team led by Juan Melero-Martin, PhD, recently found that transplanting mesenchymal stem cells along with blood vessel-forming cells naturally found in circulation improves results. This co-transplantation keeps the mesenchymal stem cells alive longer in mice after engraftment, up to a few weeks compared to hours without co-transplantation. This improved survival gives the mesenchymal stem cells sufficient time to display their full regenerative potential, generating new bone or fat tissue in the recipient mouse body. The finding was published in the Proceedings of the National Academy of Sciences (PNAS).
"We are losing mesenchymal stem cells very rapidly when we transplant them into the body, in part, because we are not giving them what they need," said Melero-Martin, an HSCI affiliated faculty member and an assistant professor of surgery at Boston Children's Hospital, Harvard Medical School.
"In the body, these cells sit very close to the capillaries, constantly receiving signals from them, and even though this communication is broken when we isolate mesenchymal stem cells in a laboratory dish, they seem to be ok because we have learned how to feed them," he said. "But when you put the mesenchymal stem cells back into the body, there is a period of time when they will not have this proximity to capillary cells and they start to die; so i
|Contact: Joseph Caputo|