Study data from Harvard University update understanding of stem cell research
2007 NOV 19 -- "In healthy adult mice, the beta cell population is not maintained by stem cells but instead by the replication of differentiated beta cells. It is not known, however, whether all beta cells contribute equally to growth and maintenance, as it may be that some cells replicate while others do not," scientists writing in the journal Plos Biology report. "Understanding precisely which cells are responsible for beta cell replication will inform attempts to expand beta cells in vitro, a potential source for cell replacement therapy to treat diabetes. Two experiments were performed to address this issue. First, the level of fluorescence generated by a pulse of histone 2B-green fluorescent protein (H2BGFP) expression was followed over time to determine how this marker is diluted with cell division; a uniform loss of label across the entire beta cell population was observed. Second, clonal analysis of dividing beta cells was completed; all clones were of comparable size. These results support the conclusion that the beta cell pool is homogeneous with respect to replicative capacity and suggest that all beta cells are candidates for in vitro expansion," wrote K. Brennand and colleagues, Harvard University. The researchers concluded: "Given similar observations in the hepatocyte population, we speculate that for tissues lacking an adult stem cell, they are replenished equally by replication of all differentiated cells." Brennand and colleagues published their study in Plos Biology (All beta cells contribute equally to islet growth and maintenance. Plos Biology, 2007;5(7):1520-1529). Additional information can be obtained by contacting D. Melton, Harvard University, Dept. of Molecular & Cellular Biology, Cambridge, MA 02138, USA. The publisher of the journal Plos Biology can be contacted at: Public Library Science, 185 Berry St., Ste. 1300, San Francisco, CA 94107, USA. Keywords: United States, Cambridge, Stem Cell Research, Harvard University. This article was prepared by Stem Cell Week editors from staff and other reports. Copyright 2007, Stem Cell Week via NewsRx.com.
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