Researchers at The University of Michigan have proven that mesenchymal stem cells are present in the lungs, and that these cells have transplanted along with the rest of the lung.
In the past, it was believed that the mesenchymal stem cells ( a versatile group of stem cells – see the information in the quote below) were derived from the patient’s lungs. We now know that they came from the donor and they they persist for years, aiding in the repair and function of the
In the cases where the donor and recipient are different genders, most of the stem cells are found to be from the donor. Some of the cells have been found more than 11 years after the transplant.
So much for the “first transplantable” claims out of Houston.
One of the most telling findings was that, in cases where the transplant donor and recipient were not of the same sex, nearly all the MSCs (about 97 percent) originated in the donor, indicating that they were present in the tissue since the time of transplantation. “We were able to isolate the cells derived from the donor as far as 11,5 years after transplantation,” says Lama, assistant professor in the Division of Pulmonary and Critical Care Medicine at the U-M Medical School. “We discovered the existence of a population of MSCs that reside and self-renew in the tissues of the adult lung – something that might hold true for other organ systems as well.
“Potentially the most important outcome of our finding is that it could lead to an understanding about therapeutic options using MSCs that reside in adult organs,” Lama continues. “These lung-derived cells are different from MSCs derived from bone marrow in the expression of various genes, which makes us believe that they are specific to the organ they are isolated from.”
The study appears online March 8 in advance of publication in the April print issue of the Journal of Clinical Investigation.
MSCs are widely seen as a potential source of therapies for numerous diseases and conditions, such as heart disease, cystic fibrosis, graft-versus-host disease, muscular dystrophy, and as a possible source for improved recovery of cancer patients undergoing chemotherapy.
Lama’s laboratory currently is working on another study involving the lung-derived MSCs that shows potential importance of these cells in lung transplantation. That study is not yet complete, but so far it indicates a very strong ability of these MSCs to suppress the immune cells that are involved in organ rejection. In addition to helping prevent organ rejection, other possible uses for the lung-derived MSCs could be therapies related to heart attack and pulmonary fibrosis, Lama says.
MSCs are termed progenitor cells; that is, they can differentiate into only limited number of cell types such as bone, cartilage and fat cells. However, previous laboratory studies have demonstrated the beneficial effect of these cells in various diseases, such as models of heart attacks and pulmonary fibrosis.
The current study of MSCs included 172 bronchoalveolar lavage fluid samples collected and analyzed from 76 lung transplant recipients at the U-M Health System. The ability to isolate these cells with relative ease from lavage fluid is a very significant finding as it provides a potential source to isolate MSCs, says Victor J. Thannickal, M.D., associate professor of Internal Medicine in the Division of Pulmonary and Critical Care Medicine and senior author on this study. “The specific roles of these cells in chronic lung diseases are yet to be fully defined, but will be an active area of research in years to come.” Source : University of Michigan Health System