In his research, McGowan Institute faculty member Stephen Strom, PhD, Professor, Division of Cellular and Molecular Pathology at the University of Pittsburgh, has found that cells isolated from placental tissues are a uniquely useful and noncontroversial stem cell source. Cells isolated from the placenta have been the subject of intense investigation because many of the cells express characteristics of multipotent or even pluripotent stem cells. Cells isolated from placentas also have some unique properties as compared to some other stem cell sources in that they are isolated from a tissue that is normally discarded following birth, they are quite plentiful and easily isolated, and they do not produce tumors when transplanted.
"My lab was looking at alternative stem cells, and we were trying to identify renewable and what was perceived by some as a more ethical source," Dr. Strom said.
Cells from the placental tissues such as amnion and chorion have been reported to display multilineage differentiation and surface marker and gene expression patterns consistent with embryonic stem and mesenchymal stem cells, respectively. When subjected to specific differentiation protocols, amniotic epithelial cells display markers of differentiation to cardiomyocytes, neurons, pancreatic cells, and hepatocytes.
Dr. Strom and his colleagues have reported that if specific and efficient methods could be developed to induce differentiation of these cells to hepatocytes, the amnion may become a useful source of cells for liver transplants. Other research efforts have shown that stem cells contained in the amniotic membrane may be useful for cellular repair of the damaged heart. These stem cells may even be used to expedite damage caused by burns, a clinical application that a Pittsburgh-based startup company is now exploring built on his work.
Placentas, usually discarded after births, are a rich source of stem cells that can be coaxed to accelerate healing by simply being sprinkled onto a wound, Dr. Strom said.
The first international Workshop on Placenta Derived Stem Cells was held in Brescia, Italy, in 2007. During the Workshop, Dr. Strom spoke of the features of placenta derived stems cells and their clinical potential. Later, Dr. Strom was part of the published review to summarize and provide the state-of-the-art of research in this field, addressing aspects such as cell isolation protocols and characteristics of these cells, as well as providing preliminary indications of the possibilities for use of these cells in future clinical applications.
Abstract (Naive rat amnion-derived cell transplantation improved left ventricular function and reduced myocardial scar of postinfarcted heart. Fujimoto KL, Miki T, Liu LJ, Hashizume R, Strom SC, Wagner WR, Keller BB, Tobita K. Cell Transplantation. 2009;18(4):477-86.)
Abstract (Production of hepatocyte-like cells from human amnion. Miki T, Marongiu F, Ellis EC, Dorko K, Mitamura K, Ranade A, Gramignoli R, Davila J, Strom SC. Methods in Molecular Biology. 2009;481:155-68.)
Abstract (Concise review: isolation and characterization of cells from human term placenta: outcome of the first international Workshop on Placenta Derived Stem Cells. Parolini O, Alviano F, Bagnara GP, Bilic G, Bühring HJ, Evangelista M, Hennerbichler S, Liu B, Magatti M, Mao N, Miki T, Marongiu F, Nakajima H, Nikaido T, Portmann-Lanz CB, Sankar V, Soncini M, Stadler G, Surbek D, Takahashi TA, Redl H, Sakuragawa N, Wolbank S, Zeisberger S, Zisch A, Strom SC. Stem Cells. 2008 Feb;26(2):300-11.)
Preliminary Program--Workshop on Placenta Derived Stem Cells, March 2007